How to make LED flashlights yourself. DIY LED flashlights

For safety and the ability to continue active activity in the dark, a person needs artificial lighting. Primitive people pushed the darkness apart, setting fire to tree branches, then invented a torch and a kerosene stove. And only after the invention of the prototype of the modern battery by the French inventor George Leclanche in 1866, and in 1879 by Thomson Edison of the incandescent lamp, did David Meisel have the opportunity to patent the first electric lantern in 1896.

Since then, nothing has changed in the electrical circuit of new lantern samples, until in 1923 the Russian scientist Oleg Vladimirovich Losev found a connection between luminescence in silicon carbide and the pn-junction, and in 1990, scientists failed to create an LED with a higher light output, which allows replacing a light bulb. incandescent. The use of LEDs instead of incandescent lamps, due to the low power consumption of LEDs, has made it possible to significantly increase the operating time of flashlights with the same capacity of batteries and accumulators, increase the reliability of flashlights and practically remove all restrictions on their area of \u200b\u200buse.

The LED rechargeable flashlight that you see in the photo came to me for repair with a complaint that the Lentel GL01 Chinese flashlight bought the other day for $ 3 does not shine, although the battery charge indicator is on.

External inspection of the lantern made a positive impression. High-quality molded body, comfortable handle and switch. The plugs for connecting to the household network for charging the battery are retractable, which eliminates the need to store the power cord.

Attention! Care should be taken when disassembling and repairing the flashlight if it is connected to the mains. Touching exposed circuitry while connected to the mains may result in electric shock.

How to disassemble the Lentel GL01 LED rechargeable torch

Although the flashlight was subject to warranty repair, remembering my walks during the warranty repair of a failed electric kettle (the kettle was expensive and the heating element burned out in it, so it was not possible to repair it with my own hands), I decided to do the repair myself.

It turned out to be easy to disassemble the lantern. It is enough to turn the ring securing the protective glass by a small angle counterclockwise and pull it off, then unscrew a few screws. It turned out that the ring is fixed to the body using a bayonet connection.

After removing one of the halves of the flashlight body, access to all its nodes appeared. On the left in the photo, a printed circuit board with LEDs is visible, to which a reflector (light reflector) is attached using three self-tapping screws. In the center there is a black battery with unknown parameters, there is only a marking of the polarity of the terminals. To the right of the battery is a printed circuit board for the charger and display. On the right is a power plug with retractable rods.

Upon closer examination of the LEDs, it turned out that there were black spots or dots on the emitting surfaces of the crystals of all LEDs. It became clear even without checking the LEDs with a multimeter that the flashlight does not shine due to their burnout.

There were also blackened areas on the crystals of two LEDs installed as a backlight on the battery charging indication board. In LED lamps and strips, one LED usually fails, and working as a fuse, protects the rest from burnout. And in the lantern, all nine LEDs went out of order at the same time. The battery voltage could not increase to a value that could damage the LEDs. To find out the reason, I had to draw an electrical schematic diagram.

Finding the cause of the flashlight failure

The electric circuit of the lantern consists of two functionally complete parts. The part of the circuit located to the left of the switch SA1 serves as a charger. And the part of the circuit shown to the right of the switch provides a glow.

The charger works as follows. The voltage from the 220 V household network is supplied to the current-limiting capacitor C1, then to the bridge rectifier assembled on VD1-VD4 diodes. From the rectifier, voltage is supplied to the battery terminals. Resistor R1 serves to discharge the capacitor after removing the flashlight plug from the network. Thus, electric shock from the discharge of the capacitor is excluded in the event of accidental hand touching of two pins of the plug simultaneously.

The HL1 LED, connected in series with the current-limiting resistor R2 in the opposite direction with the upper right diode of the bridge, as it turned out, always lights up when the plug is inserted into the network, even if the battery is faulty or disconnected from the circuit.

The SA1 operating mode switch is used to connect individual groups of LEDs to the battery. As you can see from the diagram, it turns out that if the flashlight is connected to the mains for charging and the switch slider is in position 3 or 4, then the voltage from the battery charger also goes to the LEDs.

If a person turned on the flashlight and found that it did not work, and, not knowing that the switch engine must be set to the "off" position, which is not said in the flashlight operating instructions, connect the flashlight to the mains for charging, then at the expense voltage surge at the output of the charger, a voltage significantly higher than the calculated one will hit the LEDs. The current will flow through the LEDs in excess of the permissible current and they will burn out. With the aging of the acid battery due to the sulfation of the lead plates, the battery charge voltage increases, which also leads to burnout of the LEDs.

Another circuit solution that surprised me was the parallel connection of seven LEDs, which is unacceptable, since the current-voltage characteristics of even LEDs of the same type are different and therefore the current passing through the LEDs will also not be the same. For this reason, when choosing the value of the resistor R4 on the basis of the maximum permissible current flowing through the LEDs, one of them may overload and fail, and this will lead to an overcurrent of the parallel connected LEDs, and they will also burn out.

Alteration (modernization) of the electric circuit of the lantern

It became obvious that the breakdown of the lantern was due to mistakes made by the developers of its electrical circuit diagram. To repair the flashlight and exclude its repeated breakdown, it is necessary to redo it by replacing the LEDs and making minor changes to the electrical circuit.

In order for the battery charge indicator to really signal its charging, it is necessary to turn on the HL1 LED in series with the battery. The LED needs a current of several milliamps to light up, and the current output from the charger should be about 100 mA.

To ensure these conditions, it is enough to disconnect the HL1-R2 chain from the circuit in the places indicated by the red crosses and install an additional 47 Ohm resistor Rd in parallel with it with a power of at least 0.5 W. The charge current flowing through Rd will create a voltage drop of about 3 V across it, which will provide the necessary current for the HL1 indicator to glow. At the same time, the connection point HL1 and Rd must be connected to pin 1 of switch SA1. In this simple way, the possibility of supplying voltage from the charger to the EL1-EL10 LEDs during battery charging will be excluded.

To equalize the magnitude of the currents flowing through the EL3-EL10 LEDs, it is necessary to exclude the resistor R4 from the circuit and in series with each LED, connect a separate resistor of 47-56 Ohm.

Electrical diagram after revision

Minor changes made to the circuit have increased the information content of the charge indicator of an inexpensive Chinese LED flashlight and greatly increased its reliability. I hope that the manufacturers of LED lights, after reading this article, will make changes to the wiring diagrams of their products.

After the modernization, the electrical circuit diagram took the form as in the drawing above. If you need to illuminate with a flashlight for a long time and you do not need a high brightness of its glow, you can additionally install a current-limiting resistor R5, due to which the operating time of the flashlight without recharging will double.

Repair of LED rechargeable flashlight

After disassembly, first of all, you need to restore the working capacity of the flashlight, and only then do the modernization.

Checking the LEDs with a multimeter confirmed their malfunction. Therefore, all the LEDs had to be evaporated and the holes for installing new diodes had to be freed from the solder.

Judging by their appearance, the board had lamp LEDs from the HL-508H series with a diameter of 5 mm. There were HK5H4U type LEDs from a linear LED lamp with similar technical characteristics. They came in handy for repairing the lantern. When soldering the LEDs to the board, you must remember to observe the polarity, the anode must be connected to the positive terminal of the battery or battery.

After replacing the LEDs, the PCB was connected to the circuit. The brightness of some LEDs was slightly different from others due to the common current-limiting resistor. To eliminate this drawback, it is necessary to remove the resistor R4 and replace it with seven resistors, connecting it in series with each LED.

To select a resistor that provides an optimal LED operating mode, the dependence of the current flowing through the LED on the value of the series-connected resistance at a voltage of 3.6 V, equal to the voltage battery lantern.

Based on the conditions for using the flashlight (in the event of an interruption in the supply of electricity to the apartment), high brightness and illumination range were not required, therefore the resistor was chosen with a nominal value of 56 ohms. With such a current-limiting resistor, the LED will operate in light mode, and power consumption will be economical. If it is required to squeeze out the maximum brightness from the flashlight, then you should use a resistor, as can be seen from the table, with a nominal value of 33 Ohms and make two modes of operation of the flashlight, turning on another common current-limiting resistor (in the diagram R5) with a nominal value of 5.6 Ohms.

To connect a resistor in series with each LED, you must first prepare the printed circuit board. To do this, you need to cut on it one by one any current-carrying track suitable for each LED and make additional contact pads. The current-carrying paths on the board are protected with a layer of varnish, which must be scraped off with a knife blade to copper, as in the photo. Then, tin the bare contact pads with solder.

It is better and more convenient to prepare a printed circuit board for mounting resistors and solder them if the board is fixed on a standard reflector. In this case, the surface of the LED lenses will not be scratched, and it will be more convenient to work.

Connecting the diode board after repair and modernization to the flashlight battery showed sufficient for illumination and the same brightness of all LEDs.

I didn't have time to repair the previous flashlight, when the second one got into repair, with the same malfunction. I did not find information about the manufacturer and technical characteristics on the body of the flashlight, but judging by the handwriting of the manufacture and the reason for the breakdown, the manufacturer is the same, the Chinese Lentel.

By the date on the body of the flashlight and on the battery, it was possible to establish that the flashlight was already four years old and, according to its owner, the flashlight worked flawlessly. Obviously, the flashlight lasted a long time thanks to the warning sign "Do not turn on while charging!" on the hinged lid covering the compartment, which contains the plug for connecting the flashlight to the mains to charge the battery.

In this model of the flashlight, the LEDs are included in the circuit according to the rules, a 33 Ohm resistor is installed in series with each. The size of the resistor is easy to find by color coding using an online calculator. Checking with a multimeter showed that all the LEDs are faulty, the resistors were also open-circuit.

Analysis of the reasons for the failure of the LEDs showed that due to the sulfation of the plates of the acid battery, its internal resistance increased and, as a result, its charging voltage increased several times. During charging, the flashlight was turned on, the current through the LEDs and resistors exceeded the limit, which led to their failure. I had to replace not only the LEDs, but all the resistors. Based on the above specified operating conditions of the flashlight, 47 Ohm resistors were selected for replacement. The resistor value for any type of LED can be calculated using an online calculator.

Redesign of the battery charging mode indication circuit

The lamp has been repaired, and you can start making changes to the battery charging indication circuit. For this, it is necessary to cut the track on the printed circuit board of the charger and indication in such a way that the HL1-R2 chain from the side of the LED is disconnected from the circuit.

The lead-acid AGM battery was brought to a deep discharge, and an attempt to charge it with a standard charger was unsuccessful. I had to charge the battery using a stationary power supply with the function of limiting the load current. The battery was supplied with a voltage of 30 V, while at the first moment of time it consumed only a few mA of current. Over time, the current began to increase and after a few hours it increased to 100 mA. After fully charged, the battery was installed in the flashlight.

Charging deeply discharged lead-acid AGM batteries after long-term storage with increased voltage allows them to restore their performance. I have tested the method on AGM batteries more than a dozen times. New batteries, which do not want to be charged from standard chargers, when charged from a constant source at a voltage of 30 V, are restored to almost their original capacity.

The battery was discharged several times by turning on the flashlight in operating mode and charged using a standard charger. The measured charge current was 123 mA, with a voltage at the battery terminals of 6.9 V. Unfortunately, the battery was worn out and it was enough to operate the flashlight for 2 hours. That is, the capacity of the battery was about 0.2 A × hour, and for a long-term operation of the flashlight, it needs to be replaced.

The HL1-R2 chain on the PCB was well placed, and it was necessary to cut just one conductor at an angle, as in the photo. The cutting width must be at least 1 mm. Calculation of the resistor rating and testing in practice showed that for the stable operation of the battery charging indicator, a 47 Ohm resistor with a power of at least 0.5 W is required.

The photo shows a printed circuit board with a soldered current limiting resistor. After this modification, the battery charge indicator only lights up if the battery is actually being charged.

Modernization of the mode switch

To complete the repair and modernization of the lanterns, it is necessary to re-solder the wires at the switch terminals.

In the models of repaired lamps, a four-position slide-type switch is used to turn on. The average conclusion in the above photograph is general. When the switch slider is in the extreme left position, the common terminal is connected to the left terminal of the switch. When you move the switch slider from the extreme left position one position to the right, its general output is connected to the second output, and upon further movement of the slider sequentially to 4 and 5 outputs.

To the middle common terminal (see photo above), you need to solder the wire coming from the positive terminal of the battery. Thus, it will be possible to connect the battery to a charger or LEDs. You can solder a wire from the main board with LEDs to the first terminal, and a 5.6 ohm current-limiting resistor R5 can be soldered to the second to enable the flashlight to switch to energy-saving mode. Solder the lead from the charger to the rightmost terminal. This will eliminate the possibility of turning on the flashlight while charging the battery.

Repair and modernization
LED rechargeable flashlight "Foton PB-0303"

Another example from a series of Chinese-made LED lanterns, called Photon PB-0303 LED floodlight, came into my repair. The flashlight did not react when the power button was pressed, an attempt to charge the flashlight battery using a charger was unsuccessful.

The flashlight is powerful, expensive, and costs about $ 20. According to the manufacturer, the luminous flux of the flashlight reaches 200 meters, the body is made of shock-resistant ABS plastic, the kit includes a separate charger and a shoulder strap.

Photon LED flashlight has good maintainability. To gain access to the electrical circuit, simply unscrew the plastic ring holding the protective glass by rotating the ring counterclockwise while looking at the LEDs.

When repairing any electrical appliance, troubleshooting always begins with the power source. Therefore, the first thing was measured with a multimeter turned on in the mode, the voltage at the terminals of the acid battery. It was 2.3 V, instead of 4.4 V required. The battery has been completely discharged.

When the charger was connected, the voltage at the battery terminals did not change, it became obvious that the charger was not working. The flashlight was used until the battery was completely discharged, and then it was not used for a long time, which led to a deep discharge of the battery.

It remains to check the health of the LEDs and other elements. To do this, the reflector was removed, for which six screws were unscrewed. On the printed circuit board there were only three LEDs, a chip (microcircuit) in the form of a droplet, a transistor and a diode.

From the board and the battery, five wires went into the handle. In order to understand their connection, it was necessary to disassemble it. To do this, use a Phillips screwdriver to unscrew two screws inside the lantern, which were located next to the hole into which the wires went.

To detach the handle of the flashlight from its body, it must be moved away from the fastening screws. This must be done carefully so as not to tear off the wires from the board.

As it turned out, there were no electronic elements in the pen. Two white wires were soldered to the terminals of the on / off button of the flashlight, and the rest to the connector for connecting the charger. A red wire was soldered to pin 1 of the connector (conditional numbering), which was soldered with the second end to the positive input of the printed circuit board. A blue and white conductor was soldered to the second contact, which was soldered to the negative side of the printed circuit board with the second end. A green wire was soldered to pin 3, the other end of which was soldered to the negative terminal of the battery.

Electrical circuit diagram

Having dealt with the wires hidden in the pen, you can draw an electrical schematic diagram of the Photon lantern.

From the negative terminal of the GB1 battery, the voltage is supplied to terminal 3 of the X1 connector and then from its terminal 2 through the blue-white conductor to the printed circuit board.

Connector X1 is designed in such a way that when the charger plug is not inserted into it, pins 2 and 3 are connected to each other. When the plug is inserted, pins 2 and 3 are disconnected. Thus, automatic disconnection of the electronic part of the circuit from the charger is ensured, excluding the possibility of accidental switching on of the flashlight while charging the battery.

From the positive terminal of the GB1 battery, voltage is applied to D1 (microcircuit-chip) and the emitter of the S8550 bipolar transistor. The CHIP performs only the function of a trigger, which allows the button to turn on or off the EL LEDs (⌀8 mm, white color, power 0.5 W, consumption current 100 mA, voltage drop 3 V) without latching. When the S1 button is pressed for the first time from the D1 microcircuit, a positive voltage is applied to the base of the Q1 transistor, it opens and the supply voltage is supplied to the EL1-EL3 LEDs, the flashlight turns on. When the S1 button is pressed again, the transistor closes and the flashlight turns off.

From a technical point of view, such a circuit design is illiterate, since it increases the cost of the flashlight, reduces its reliability, and in addition, due to the voltage drop across the junction of the transistor Q1, up to 20% of the battery capacity is lost. Such a circuit solution is justified if it is possible to adjust the brightness of the light beam. In this model, instead of a button, it was enough to put a mechanical switch.

It was a surprise that in the circuit the EL1-EL3 LEDs are connected in parallel to the battery like incandescent bulbs, without current-limiting elements. As a result, when switched on, a current flows through the LEDs, the value of which is limited only by the internal resistance of the battery and when it is fully charged, the current can exceed the permissible value for the LEDs, which will lead to their failure.

Checking the functionality of the electrical circuit

To check the operability of the microcircuit, transistor and LEDs from an external power source with a current limiting function, a DC voltage of 4.4 V was applied, observing polarity, directly to the power pins of the printed circuit board. The current limit was set to 0.5 A.

After pressing the power button, the LEDs lit up. After pressing again, they went out. The LEDs and the microcircuit with the transistor turned out to be working properly. It remains to deal with the battery and charger.

Recovery of an acid battery

Since the 1.7 A acid battery was completely discharged, and the standard charger was faulty, I decided to charge it from a stationary power supply. When connecting the battery for charging to a power supply with a set voltage of 9 V, the charging current was less than 1 mA. The voltage was increased, to 30 V - the current increased to 5 mA, and after an hour under this voltage it was already 44 mA. Then the voltage was reduced to 12 V, the current dropped to 7 mA. After 12 hours of charging the battery at a voltage of 12 V, the current rose to 100 mA, and the battery was charged with this current for 15 hours.

The temperature of the battery case was within normal limits, which indicated that the charging current was used not to generate heat, but to store energy. After charging the battery and finalizing the circuit, which will be discussed below, tests were carried out. The flashlight with the recovered battery illuminated continuously for 16 hours, after which the beam brightness began to drop and therefore it was turned off.

Using the method described above, I had to repeatedly restore the performance of deeply discharged small-sized acid batteries. As practice has shown, only serviceable batteries, which have been forgotten for a while, can be restored. Acid batteries that have exhausted their resource cannot be restored.

Charger repair

Measurement of the voltage value with a multimeter at the contacts of the output connector of the charger showed its absence.

Judging by the sticker glued to the adapter case, it was a power supply that emitted an unstabilized constant voltage of 12 V with a maximum load current of 0.5 A. There were no elements in the electrical circuit that limit the amount of charging current, so the question arose, why Was an ordinary power supply used as a charger?

When the adapter was opened, a characteristic smell of burnt electrical wiring appeared, which indicated that the transformer winding had burned out.

The dialing of the primary winding of the transformer showed that it was open. After cutting the first layer of the tape that insulates the primary winding of the transformer, a thermal fuse was found, designed for a response temperature of 130 ° C. Testing showed that both the primary winding and the thermal fuse are defective.

Repair of the adapter was economically impractical, since it was necessary to rewind the primary winding of the transformer and install a new thermal fuse. I replaced it with a similar one, which was at hand, for a DC voltage of 9 V. The flexible cord with a connector had to be re-soldered from the burnt out adapter.

The photo shows a drawing of an electrical circuit of a burned-out power supply unit (adapter) of the Photon LED flashlight. The replacement adapter was assembled according to the same scheme, only with an output voltage of 9 V. This voltage is quite enough to provide the required battery charging current with a voltage of 4.4 V.

For fun, I connected the flashlight to a new power supply and measured the charging current. Its value was 620 mA, and this is at a voltage of 9 V. At a voltage of 12 V, the current was about 900 mA, significantly exceeding the load capacity of the adapter and the recommended charging current of the battery. For this reason, the primary winding of the transformer burned out from overheating.

Completion of the electrical circuit diagram
LED rechargeable flashlight "Photon"

To eliminate circuitry violations in order to ensure reliable and long-term operation, changes were made to the lantern circuit and the printed circuit board was revised.

The photo shows the electrical schematic diagram of the converted LED flashlight "Photon". Additional installed radio elements are shown in blue. Resistor R2 limits the battery charge current to 120 mA. To increase the charging current, you need to reduce the value of the resistor. Resistors R3-R5 limit and equalize the current flowing through the LEDs EL1-EL3 when the lamp is on. The EL4 LED with a series-connected current-limiting resistor R1 is installed to indicate the battery charging process, since the developers of the flashlight design did not take care of this.

To install current limiting resistors on the board, the printed paths were cut, as shown in the photo. The charge current limiting resistor R2 was soldered at one end to the contact pad, to which the positive wire from the charger was previously soldered, and the soldered wire was soldered to the second terminal of the resistor. An additional wire (yellow in the photo) was soldered to the same contact pad, designed to connect the battery charging indicator.

Resistor R1 and LED indicator EL4 were placed in the handle of the flashlight, next to the connector for the charger X1. The LED anode pin was soldered to pin 1 of the X1 connector, and to the second pin, the LED cathode, a current-limiting resistor R1. A wire (yellow in the photo) was soldered to the second terminal of the resistor, connecting it to the terminal of the resistor R2, soldered to the printed circuit board. Resistor R2, for ease of installation, could be placed in the handle of the flashlight, but since it heats up when charging, I decided to place it in a freer space.

When finalizing the circuit, MLT resistors with a power of 0.25 W were used, except for R2, which is designed for 0.5 W. EL4 LED is suitable for any type and color of light.

This photo shows the charging indicator while charging the battery. The installation of the indicator made it possible not only to monitor the battery charging process, but also to monitor the presence of voltage in the network, the health of the power supply and the reliability of its connection.

How to replace a burnt out CHIP

If suddenly the CHIP - a specialized microcircuit without marking in the "Photon" LED flashlight, or similar, assembled according to a similar scheme, fails, then to restore the flashlight's performance it can be successfully replaced with a mechanical switch.

To do this, you need to remove the D1 chip from the board, and instead of the Q1 transistor key, connect an ordinary mechanical switch, as shown in the above electrical diagram. The light switch can be installed in place of the S1 button or in any other suitable place.

Repair with modernization
LED Flashlight Keyang KY-9914

A visitor to the site, Marat Purliev from Ashgabat, shared in a letter the results of repairing the Keyang KY-9914 LED flashlight. In addition, he submitted a photo, diagrams, a detailed description and agreed to publish the information, for which I express my gratitude to him.

Thank you for the article "DIY repair and modernization of LED lamps Lentel, Foton, Smartbuy Colorado and RED".

Using the examples of repairs, I repaired and upgraded the Keyang KY-9914 flashlight, in which four of the seven LEDs burned out, and the battery was worn out. The LEDs burned out due to switching the switch while charging the battery.

In the revised wiring diagram, changes are highlighted in red. I replaced the faulty acid battery with three Sanyo Ni-NH 2700 rechargeable AA batteries connected in series, which were at hand.

After reworking the flashlight, the current consumption of the LEDs in two switch positions was 14 and 28 mA, and the battery charge current was 50 mA.

Repair and alteration of LED flashlight
14Led Smartbuy Colorado

Stopped turning on led torch Smartbuy Colorado, although three AAA batteries were new.

The waterproof housing was made of anodized aluminum alloy and was 12 cm long. The flashlight looked stylish and was easy to use.

How to check the batteries in the LED flashlight for suitability

The repair of any electrical appliance begins with checking the power source, therefore, despite the fact that new batteries were installed in the flashlight, repairs should begin with checking them. In a Smartbuy lantern, batteries are installed in a special container, in which they are connected in series using jumpers. In order to access the flashlight batteries, you need to disassemble by rotating the back cover counterclockwise.

Insert the batteries into the container observing the polarity indicated on it. The polarity is also marked on the container, so it must be inserted into the body of the lantern with the side with the "+" sign.

First of all, it is necessary to visually check all the contacts of the container. If there are traces of oxides on them, then the contacts must be cleaned to a shine using sandpaper or scraped off the oxide with a knife blade. To avoid re-oxidation of the contacts, they can be lubricated with a thin layer of any machine oil.

Next, you need to check the suitability of the batteries. To do this, touching the probes of the multimeter, which is included in the DC voltage measurement mode, it is necessary to measure the voltage at the container contacts. Three batteries are connected in series and each of them should provide a voltage of 1.5 V, therefore, the voltage at the terminals of the container should be 4.5 V.

If the voltage is less than the specified, then it is necessary to check the correct polarity of the batteries in the container and measure the voltage of each of them individually. Perhaps only one of them sat down.

If everything is in order with the batteries, then you need to insert, observing the polarity, the container into the body of the lantern, screw the cover and check it for operability. In this case, one should pay attention to the spring in the cover, through which the supply voltage is transmitted to the body of the flashlight and from it directly to the LEDs. There should be no traces of corrosion on its end.

How to check the health of the switch

If the batteries are good and the contacts are clean, but the LEDs are off, then you need to check the switch.

The Smartbuy Colorado has a push-button sealed switch with two fixed positions, a short wire coming from the positive terminal of the battery container. When the switch button is pressed for the first time, its contacts are closed, and when the switch is pressed again, they open.

Since batteries are installed in the lantern, you can also check the switch using a multimeter turned on in voltmeter mode. To do this, turn it counterclockwise, looking at the LEDs, unscrew its front part and put it aside. Then, with one probe of the multimeter, touch the body of the flashlight, and with the second touch the contact, which is located deep in the center of the plastic part shown in the photo.

The voltmeter should show a voltage of 4.5 V. If there is no voltage, press the switch button. If it is working properly, then the voltage will appear. Otherwise, the switch must be repaired.

Checking the health of the LEDs

If in the previous steps of the search it was not possible to find a malfunction, then at the next stage you need to check the reliability of the contacts supplying the supply voltage to the board with LEDs, the reliability of their soldering and serviceability.

The printed circuit board with the LEDs sealed into it is fixed in the head of the flashlight with a steel spring-loaded ring through which the supply voltage from the negative terminal of the battery container is simultaneously fed to the LEDs along the body of the flashlight. The photo shows the ring from the side with which it presses the printed circuit board.

The retaining ring is fixed quite tightly, and it was possible to remove it only with the help of the device shown in the photo. Such a hook can be bent out of a steel strip with your own hands.

After removing the retaining ring, the printed circuit board with LEDs, which is shown in the photo, was easily removed from the head of the lantern. The absence of current-limiting resistors immediately struck, all 14 LEDs were connected in parallel and through a switch directly to the batteries. Connecting LEDs directly to a battery is unacceptable, since the amount of current flowing through the LEDs is limited only by the internal resistance of the batteries and can damage the LEDs. At best, it will greatly shorten their service life.

Since all the LEDs in the lantern were connected in parallel, it was not possible to check them using a multimeter included in the resistance measurement mode. Therefore, a DC supply voltage of 4.5 V was applied to the printed circuit board from an external source with a current limitation to 200 mA. All LEDs lit up. It became apparent that the flashlight malfunction was a poor contact of the printed circuit board with the retaining ring.

LED lamp current consumption

For interest, I measured the current consumption by LEDs from batteries when they were turned on without a current-limiting resistor.

The current was over 627 mA. The flashlight has LEDs of the HL-508H type, the operating current of which should not exceed 20 mA. 14 LEDs are connected in parallel, therefore, the total consumption current should not exceed 280 mA. Thus, the current flowing through the LEDs has more than doubled the nominal current.

Such a forced operation of LEDs is unacceptable, as it leads to overheating of the crystal, and as a result, premature failure of the LEDs. An additional disadvantage is that the batteries drain quickly. They will be enough if the LEDs do not burn out earlier, for no more than an hour of operation.

The design of the flashlight did not allow soldering current-limiting resistors in series with each LED, so I had to install one common one for all LEDs. The resistor value had to be determined experimentally. For this, the flashlight was powered from standard batteries and an ammeter was connected in series with a 5.1 ohm resistor in the positive wire break. The current was about 200 mA. When installing an 8.2 Ohm resistor, the current consumption was 160 mA, which, as the test showed, is quite enough for good lighting at a distance of at least 5 meters. The resistor did not heat up to the touch, so any power will do.

Alteration of the structure

After the study, it became obvious that for reliable and durable operation of the flashlight, it is necessary to additionally install a current-limiting resistor and duplicate the connection of the printed circuit board with LEDs and a fixing ring with an additional conductor.

If earlier it was necessary for the negative bus of the printed circuit board to touch the lamp body, then due to the installation of the resistor, it was necessary to exclude the touch. For this, a corner was ground off from the printed circuit board along its entire circumference, from the side of the current-carrying paths using a file.

To prevent the pressure ring from touching the current-carrying paths when fixing the printed circuit board, four rubber insulators with a thickness of about two millimeters were glued to it with Moment glue, as shown in the photograph. Insulators can be made from any dielectric material, such as plastic or thick cardboard.

The resistor was previously soldered to the clamping ring, and a piece of wire was soldered to the extreme track of the PCB. An insulating tube was put on the conductor, and then the wire was soldered to the second terminal of the resistor.

After a simple DIY upgrade of the flashlight, it began to turn on stably and the light beam illuminated objects well at a distance of more than eight meters. Additionally, the battery life has more than tripled, and the reliability of the LEDs has increased dramatically.

Analysis of the reasons for the failure of refurbished Chinese LED lights showed that they all failed due to illiterately designed electrical circuits. It remains only to find out whether this was done on purpose in order to save on components and reduce the life of the flashlights (so that new ones would be bought more), or as a result of the developers' ignorance. I tend to the first assumption.

Repair of LED lamp RED 110

A flashlight with a built-in acid battery from a Chinese manufacturer of the RED trademark got into repair. The lantern had two emitters: - with a beam in the form of a narrow beam and emitting diffused light.

The photo shows the appearance of the RED 110 flashlight. I liked the flashlight right away. Convenient body shape, two modes of operation, loop for suspension on the neck, retractable plug for charging. In the lantern, the section of LEDs for the scattered light shone, but not for the narrow beam.

For the repair, the black ring was first unscrewed, fixing the reflector, and then one self-tapping screw was unscrewed in the loop area. The body easily split into two halves. All parts were fixed on self-tapping screws and easily removed.

The charger circuit was made according to the classical scheme. From the network, through a current-limiting capacitor with a capacity of 1 μF, voltage was supplied to a rectifier bridge of four diodes and then to the battery terminals. The voltage from the battery to the LED of the narrow beam was supplied through a 460 Ohm current-limiting resistor.

All parts were mounted on a single sided printed circuit board. The wires were soldered directly to the pads. The appearance of the printed circuit board is shown in the photo.

10 side light LEDs were connected in parallel. The supply voltage was supplied to them through a common current-limiting resistor 3R3 (3.3 Ohm), although according to the rules, a separate resistor must be installed for each LED.

An external examination of the LED of a narrow beam of defects was not found. When power was applied through the flashlight switch from the battery, the voltage at the terminals of the LED was present, and it heated up. It became obvious that the crystal was broken, and this was confirmed by a dial tone with a multimeter. The resistance was 46 Ohm for any connection of the probes to the LED terminals. The LED was defective and needed to be replaced.

For the convenience of work, the wires were soldered from the LED board. After freeing the leads of the LED from the solder, it turned out that the LED is firmly held by the entire plane of the reverse side on the PCB. For his department it was necessary to fix the board in the table temples. Next, install the sharp end of the knife at the junction of the LED with the board and lightly hit the knife handle with a hammer. The LED bounced off.

As usual, there was no marking on the LED body. Therefore, it was necessary to determine its parameters and select a suitable replacement. Based on the overall dimensions of the LED, the battery voltage and the size of the current-limiting resistor, it was determined that a 1 W LED (current 350 mA, voltage drop 3 V) is suitable for replacement. White LED6000Am1W-A120 was selected for repair from the "Reference Table of Popular SMD LED Parameters".

The printed circuit board on which the LED is installed is made of aluminum and at the same time serves to remove heat from the LED. Therefore, when installing it, it is necessary to ensure good thermal contact due to the tight fit of the back plane of the LED to the printed circuit board. To do this, before sealing, thermal paste was applied to the contact points of the surfaces, which is used when installing a radiator on a computer processor.

In order to ensure a snug fit of the LED plane to the board, you must first put it on a plane and bend the leads slightly upward so that they recede from the plane by 0.5 mm. Next, tin the conclusions with solder, apply thermal paste and install the LED on the board. Then press it to the board (it is convenient to do this with a screwdriver with the bat removed) and warm up the leads with a soldering iron. Next, remove the screwdriver, press it with a knife at the bend of the output to the board and warm it up with a soldering iron. After the solder has hardened, remove the knife. Due to the spring properties of the pins, the LED will be tightly pressed against the board.

The polarity must be observed when installing the LED. True, in this case, if a mistake is made, then it will be possible to swap the supply wires. The LED is soldered and you can check its operation and measure the current consumption and voltage drop.

The current flowing through the LED was 250 mA, the voltage drop was 3.2 V. Hence the power consumption (you need to multiply the current by the voltage) was 0.8 W. It was possible to increase the operating current of the LED by reducing the resistance of 460 Ohm, but I did not do this, since the brightness of the glow was sufficient. But the LED will work in a lighter mode, heat up less and increase the operating time of the flashlight from one charge.

Checking the heating of an LED that has been operating for an hour has shown effective heat dissipation. He heated up to a temperature of no more than 45 ° C. Sea trials have shown sufficient lighting range in the dark, more than 30 meters.

Replacing the acid battery in the LED flashlight

An acid battery that has failed in an LED flashlight can be replaced with a similar acid battery, lithium-ion (Li-ion) or nickel-metal hydride (Ni-MH) batteries of AA or AAA size.

In the repaired Chinese flashlights, lead-acid AGM batteries of various dimensions without marking with a voltage of 3.6 V were installed. According to the calculation, the capacity of these batteries is from 1.2 to 2 A × hours.

On sale you can find a similar acid battery from a Russian manufacturer for the 4V 1Ah Delta DT 401 UPS, which has an output voltage of 4 V at a capacity of 1 A × hour, costing a couple of dollars. For replacement, it is quite simple, observing the polarity, to re-solder the two wires.

After several years of operation, the Lentel GL01 LED lamp, the repair of which is described at the beginning of the article, was again brought to me for repair. Diagnostics showed that the acid battery has worn out.

A Delta DT 401 battery was purchased to replace, but it turned out that its geometric dimensions were larger than the faulty one. The standard flashlight battery had dimensions of 21 × 30 × 54 mm and was 10 mm higher. I had to modify the body of the flashlight. Therefore, before buying a new battery, make sure that it fits into the body of the flashlight.

The stop in the case was removed and a part of the printed circuit board was cut off with a hacksaw for metal, from which the resistor and one LED were previously soldered.

After the revision, the new battery was well installed in the body of the flashlight and now, I hope, will last more than one year.

Replacing the acid battery
AA or AAA batteries

If it is not possible to purchase a 4V 1Ah Delta DT 401 battery, then it can be successfully replaced with any three AA or AAA finger batteries with a capacity of 1 A × hour or more, which have a voltage of 1.2 V. connect three batteries in series, observing the polarity, by soldering wires. However, economically, such a replacement is impractical, since the cost of three high-quality AA batteries can exceed the cost of buying a new LED flashlight.

But where is the guarantee that there are no errors in the electrical circuit of the new LED flashlight, and you will not have to modify it either. Therefore, I believe that replacing the lead-acid battery in the modified flashlight is advisable, as it will ensure reliable operation of the flashlight for several more years. And it will always be pleasant to use a flashlight, repaired and modernized with your own hands.

Light sources of a new generation - LEDs - are becoming more and more popular despite their still high cost.

Due to their low power consumption, they are successfully used not only in stationary lighting fixtures, but also in stand-alone ones, powered by batteries.

In this article we will talk about how you can make an LED flashlight with your own hands and what advantages it will have in comparison with the usual one.

A light emitting diode (foreign name - Light Emitting Diode or LED), like a conventional diode, consists of two semiconductors with electron and hole conductivity.

But in this case, such materials are used for which the glow in the pn-junction zone is characteristic.

Generally speaking, LEDs have been used in electronics for a long time.

But before, they barely glowed, and therefore were used only as indicators, for example, indicating that the device was turned on.

With the development of technology, LEDs have learned to make them much brighter, so that they have turned into full-fledged light sources. At the same time, their cost is constantly decreasing, although, of course, they are still very far from an ordinary light bulb.

But many buyers are willing to overpay, because LEDs have a number of advantages:

1. Consume 10 - 15 times less electricity than incandescent lamps of the same brightness.
2. They have just a huge resource, which is expressed in 50 thousand hours of work. Moreover, manufacturers back their promises with a warranty period of 2 or even 3 years.
3. They emit white light, very similar to natural.
4. They are much less susceptible to shock and vibration than other light sources.
5. They are highly resistant to voltage drops.

Thanks to all these qualities, LEDs today confidently displace other light sources from almost everywhere. They are used in everyday life, in car headlights, in advertising activities, and in portable flashlights, one of which we will now learn to make.

Required items for manufacturing

First of all, you need to get all the components that will make up the device.

There are not many of them:

1. Light-emitting diode.
2. Ferrite ring with a diameter of 10 - 15 mm.
3. Wire for winding with a diameter of 0.1 and 0.25 mm (pieces of 20 - 30 cm).
4. 1 kΩ resistor.
5. An n-p-n transistor.
6. Battery.

It's good if you can get the body from a purchased flashlight. If not, any base can be used to attach the components.

Assembly diagram

If everything is ready, we can start:

1. We make a transformer: a ferrite ring will act as a magnetic core of a homemade transformer. First, 45 turns of a winding wire with a diameter of 0.25 mm are wound on it, forming a secondary winding. In the future, an LED will be connected to it. Next, from a wire with a diameter of 0.1 mm, you need to make a primary winding with 30 turns, which will be connected to the base of the transistor.
2. Resistor Selection: The base resistor should be approximately 2K ohms.

But the value of the second resistor must be selected. This is done like this:

1. a trimmer (variable) resistor is installed in its place.
2. Having connected the flashlight to a new battery, set such a resistance on a variable resistor so that a current of 22-25 mA flows through the LED.
3. Measure the value of the resistance across the variable resistor and install a constant resistor with the same rating instead.

As you can see, the scheme is extremely simple and the error probability can be considered minimal.

DIY LED flashlight - diagram

If the flashlight nevertheless turned out to be inoperative, the reason may be as follows:

1. During the manufacture of the windings, the condition of multidirectional currents was not met. In this case, the generation of current in the secondary winding will not occur. In order for the circuit to be working, you need to either wind the windings in different directions, or swap the terminals of one of the windings.
2. The winding contains too few turns. It should be borne in mind that the required minimum is 15 turns.

If they are present in a smaller amount in the winding, current generation will again be impossible.

DIY 12 volt LED flashlight

Those who do not need a flashlight, but a whole spotlight in miniature, can assemble a device with a more powerful power source. The latter will be a 12-volt battery. This product will be somewhat large, but it will still be easy to carry.

To create a high power light source, you need to prepare the following:

• polymer pipe with a diameter of about 50 mm;
• glue for gluing PVC parts;
• a pair of threaded fittings for PVC pipes;
• screw cap;
• toggle switch;
• 12V LED;
• 12 volt battery;
• auxiliary elements for the installation of electrical wiring - heat shrink tubes, electrical tape, plastic clips.

As a power source, you can use several batteries from broken radio controlled toys, which are combined into one battery with a voltage of 12 V. Batteries, depending on their type, will need from 8 to 12.

The 12-volt LED torch is assembled like this:

1. We solder pieces of wire to the contacts of the LED, which are a couple of centimeters longer than the battery in length. In this case, it is necessary to ensure reliable isolation of the connections.
2. The wires connected to the battery and LED are equipped with special connectors that allow quick disconnect connections.
3. When assembling the circuit, the toggle switch is installed so that in relation to the LED it is on the opposite side. The electronic filling is ready and if tests have shown that it works properly, you can start making the case.

The body is made of a polymer pipe. This is done like this:

1. The pipe is cut to the desired length, after which all the electronics are placed inside it.
2. We put the battery on glue so that it remains motionless during carrying and manipulating the flashlight. Otherwise, the heavy battery can hit the LED element and damage it.
3. From both ends we glue to the pipe along the threaded fitting. There is no need to save glue - the connection must be airtight. Otherwise, water may seep into the case at this point.
4. We fix the toggle switch inside the fitting installed on the side opposite to the LED. We put the switch on the glue, while it should not protrude outward so that the plug can be screwed onto the fitting.

To switch the toggle switch, the plug will need to be unscrewed, then reinstalled in place. This is somewhat inconvenient, but such a solution ensures the complete tightness of the case.

The question of price and quality

Of all the flashlight components, the most expensive is the 12-volt LED. You will have to pay 4 - 5 USD for it.

Everything else can be obtained for free: batteries, as already mentioned, are removed from radio-controlled toys, plastic pipes and parts very often remain as waste after installing plumbing or heating in the house.

If absolutely all the components have to be purchased in the store, then the cost of the lighting device will result in about 10 USD.

A homemade LED strip lamp can be built quickly and easily. - see the manufacturing instructions and make your own unique product.

Read how to properly install an LED strip with your own hands.

Conclusion

A convenient flashlight that gives a bright light and at the same time can work for a long time without recharging the battery is always needed on the farm. As you can see, you can easily do it yourself, which will save you some amount. The main thing is to be careful and strictly adhere to all the recommendations set out in the article.

Video on the topic

At night you cannot cope without a flashlight - the main electrical device for vision. Without this object, it is generally not possible for a person to see anything in the dark. The reason for this lies in the fact that a person in the dark is not able to distinguish between colors.

Every year, more and more photos of homemade flashlights appear on the Internet, which is quite logical, since, thanks to such an invented device, you can see absolutely everything in the dark.

Today there are several varieties of flashlights. You can find not only the classic options, known to everyone, but also lights that provide for self-regulation, if necessary, the beam of light. In this article, we will consider in detail how to make a flashlight with your own hands, using only prepared materials and step-by-step instructions.

Lanterns made of paper

If you look at various diagrams and instructions on how to make a flashlight yourself, you will easily notice that making it out of paper is easier than out of any other material. Moreover, even a child under the supervision of an adult can make a beautiful flashlight out of colored paper.

You can see countless samples on the Internet and looking at them you can execute them quickly enough. If you want to make a beautiful flashlight, you can additionally decorate it with such an accessory as a paper ribbon.

A paper flashlight acts as a rather cute symbol, so even if some homemade lighting assistants do not shine at all, their functionality is forgiven.

In addition, they are so beautiful that making them is very interesting not only for children, but also for adults. Today, simple and powerful do-it-yourself flashlights become an object that is made even with kids in kindergarten.

How to decorate a flashlight?

A classic paper lantern can be interestingly transformed, for example, with the help of various decor. Ikea company demonstrates this especially successfully. Every year, their magazines show more and more different uses for garlands of lanterns on the walls and ceiling. Thanks to such an interesting piece of furniture, you can quickly and cost-effectively transform the appearance of any room.

So what does it take to make a flashlight at home? Paper, scissors, glue and some decor. Otherwise, there is a real scope for activity, which is not limited by anything.

More holes in flashlights

Today in various magazines you can find many different paper lanterns that can be made with a child of any age. You can, for example, try to make a bright pot with holes, which will decorate even a classic flashlight model. Most importantly, it will definitely replace a general developmental activity with a child over three years old.

Flashlight house

If you want to try to make ultraviolet and LED flashlights popular today, then you can try to choose the shape of a house for them. Beautiful lanterns in the form of houses or even palaces are quite simple to make. On the Internet, you can find a template for almost every taste. If you want to spend more time with your child, you can even try to draw a template for your future craft yourself.

The main thing to consider when creating this type of flashlight is the mandatory creation of grooves. In this case, you will most likely not even get dirty in the glue.

In addition, the thing will become truly unique and no one else will find it anywhere else. You can make such a flashlight in just a couple of hours. The main difference during creation will be only in the material used. For the rest, they are made in the same way as lanterns in the form of cardboard houses.

When creating such lamps, keep in mind that the accessory will never be able to become a full-fledged source of lighting. In this case, the lantern can be used as a night light in a children's room or as an additional source of lighting, for example, in the kitchen, provided that the main lighting is sufficiently bright.

DIY photo flashlight

Note!

Note!

Note!

Hello! Here is another simple alteration of an old rechargeable flashlight with an incandescent light bulb for modern elements - LED, driver, converter. A friend gave a bunch of old chargers for creativity, and he found an old flashlight from the times of the USSR, which he wanted to throw away, and I convinced him, saying that I would make a great flashlight out of it for the New Year.

The charger was based on one of the given NOKIA phone charges, for 5.5 V 300 mAh, which fit into the case like a native. After the broken plastic walls, there was a lot of space left from the disk batteries, and I installed a homemade scarf in the remaining place.

On the second half of the case, I used a SAMSUNG lithium-ion battery from a cell, which also fits perfectly. A mini toggle switch is used as a light switch. So that nothing dangles, I fixed everything with molecular glue.

The GREE LED is one of those that previously ordered a whole batch, it is installed on an aluminum radiator cut out at the base of the lamp, but since only half of its power is used here, it practically does not get hot. The diodes came in a month, they shine quite brightly, the light is neutral white as I ordered, I will insert them into other home-made flashlights.

Diode driver circuit

The driver for it is installed on the well-proven AMC7135 microcircuit. Usually, instead of C1, I usually put a 10x16V tantalum cmd capacitor. But you can apply any of the available ones, even a simple electrolytic one - everything depends only on its dimensions on the board used, but you must install it!

For an LED, a collimator is glued to the reflector, the illumination is very good, otherwise the light with an ordinary reflector has a darkish spot in the middle, which is not good.

Recently I assembled another one of the same, I only set the LED to 1 W and installed a 60-degree lens on it. The project proposed Igoran.

Discuss the article HOW TO MAKE A DIODE FLASHLIGHT FROM A CONVENTIONAL

In this article, I will tell you how to make an insanely bright rechargeable LED flashlight and turn night into day with your own hands.

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Most of us use lanterns on hikes, for night walks, or just when we go out into the dark. We usually buy these lights at hardware stores, and they shine quite dimly. To fix this, I came up with and assembled a super-powerful flashlight that is suitable for lighting the road at night, creating cool photo and video effects (like glowing spheres in science fiction), lighting a work site and much more, all at a reasonable cost.

Step 1: Materials used

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I give a list of materials used by me, you can take the same or pick up something similar.

• Switches
• Li-polymer batteries 11.1V (take the one that suits your flashlight better), I give you links to suitable models:

You will also need wires, a terminal block, fuses and holders for them, solder, heat shrink, etc.

The resulting long-range flashlight will come out about three times cheaper than store counterparts. And don't forget that the battery and charger can be used in other devices. Also, during the assembly of a hand-held flashlight, you will gain new knowledge and experience, which is priceless.

Step 2: The main working points of the assembly of the lantern

Since the diode in our floodlight consumes a huge amount of energy, up to 100 W (33 V and 3 A), it gives off a lot of heat, so it needs a serious heat sink. The one that I indicated on my list may seem too big to you, and it is, but our lantern itself is “too much”.

To provide energy to this "beast" you will need a powerful battery, for devices with high energy consumption, it should also be light and compact, after all, after all, we are making a portable flashlight - lead-acid ones immediately disappear. Lithium polymer batteries meet these requirements. These are usually installed on drones and RC models. They are small, lightweight and can be quickly discharged - just what we need for our flashlight. I have installed an 11.1V battery in my flashlight (link above).

Since the battery power is 11.1V, and the diode needs 33V, we took a step-up converter. It uses a built-in potentiometer to boost the 11.1V input to 33V output. You must make sure that the diode does not receive more than 34V, and not less than 26V. In order to monitor the output voltage of the converter, you will need a digital volt-ammeter. It shows you the voltage and amperage going to the diode. All this allows us to dim the light and helps prevent too high a current from being applied. For added protection, we will install 4A fuses at the output of the inverter. No matter how funny it is to blow up a 100W diode, you don't want to wait for delivery again.

A discharge indicator is necessary to prevent deep discharge, due to the sensitive internal chemistry of lithium polymer batteries, such an indicator is necessary. Each battery cell will be charged at a voltage of up to 4.2V per cell, and at least 3V. If the voltage drops below 3V, it quickly drops to 1V, this will damage the cell. We will prevent this by setting the discharge indicator to 3.2V (beeps) using the button at the top. But if, for some unknown reason, the voltage drops below 3.2V, quickly charge the battery to the lowest charge level, this will restore the battery cell with minimal damage.

In my flashlight I installed two switches - one, the main one, for the general power supply, the second - only for the diode. I did this so that when the light was off, the cooling system, the discharge indicator and digital voltammeter continued to work. This way I can see the voltage in the battery with the lights on or off, and I also like to hear my appliance make a noise when the main switch is turned on.

Step 3: mount the diode to the heatsink

To start installation, apply thermal paste to the diode, as shown in the picture above (since the use of thermal paste has a lot of conflicting reviews, you can not do this). After that, I screwed the aluminum heatsink, which I had idle, to the diode, and secured them to the large heatsink, like in the other picture above.

Do not tighten the nuts too much to avoid bending the diode.

You can glue the reflector lens in this step using epoxy.

Step 4: case

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I took the case from an old broken lantern. First I took out its contents — two car headlight bulbs and two small lead acid batteries. Then I modified the body a bit to accommodate the new content. For this I needed: hot melt glue, epoxy resin, sandpaper and an engraver.

First I removed some of the calipers with an engraver. Then I pre-assembled all the parts and attached the wires to the reflector, I cut off the excess length of the wires later. In such cases, epoxy always helps. Now I need to try how the assembled parts fit in the case, everything fit perfectly for me. Then I cut through the cooler vents and covered them with a piece of grill from the speaker of the old broken iPod. I also cut and sanded the holes for the digital voltammeter, discharge indicator, main switch and trimmer potentiometer, and installed them and the boost converter, using a lot of hot glue for this, because it is not visible inside the case.

Then I added some finishing touches - Velcro fasteners on the battery and on the handle of the flashlight so that it was convenient to attach to something, and pasted the stickers that came with the battery. Now it's time to get to the wires.

I think not everyone will have the luxury of a ready-made flashlight housing, and I am very interested in how you solve this problem.

Step 5: Wiring

I sketched a primitive wiring diagram for the lantern. When wiring the lantern, leave the wires long enough for the size of the case. I connected most of the wires before I put everything in the case, but you can place the components first and then pull the wires after that, it depends on your torch case.

At this point, you will need a ground and power terminal block, wires (12 or 14 US gauge, for high power connections), a 4A fuse and fuse holder, and other little things.

Do not forget to hide all connections in heat shrink. First, solder the wire to the socket of the XT60 connector, connect the switch in series with the ground wire, this switch will be the main switch. Then secure the ends to the terminal block, creating positive and ground lines (depending on the terminal block you are using, you may need to route wires from each connection to the terminals).

Boost converter

Solder the power and ground wires to the inputs.
Connect the switch to the fuse holder and connect to the negative output. Here we will connect the 4A fuse.

To adjust the voltage going to the diode, you will need access to a potentiometer. For this, I brought the trimmer potentiometer already available in the converter into access.

Digital voltammeter and diode

Connect two thin wires (red with positive, black with ground) to power the terminal block. Connect the larger black wire to the negative output of the boost converter, after the fuse holder.
The yellow wire will go to the negative output of the diode. The larger red wire will go to the positive output of the boost converter.

Discharge indicator

To connect a discharge indicator, connect the balancing connector to the ground to third pins, bite off the grounded wire, and connect to the main ground connector on the terminal block.

Step 6: what not to do

And here is a list of things NOT to do.