Starting a fluorescent lamp from 12 volts. How to power lds from a car battery

The proposed scheme allows the use of 40W (220V) fluorescent lamps from a 12V power supply (automotive accumulator battery). The circuit is very simple, it can be done by surface mounting, but it is still better to mount the elements on a printed circuit board.

This device can be useful as emergency lighting.

The step-up transformer contains 3 windings, the first is a coil feedback L, the second is the primary winding of the transformer and the 3rd winding is boosting. The feedback coil L contains 13 turns of wire with a diameter of 0.4 mm, the second winding contains 58-60 turns of wire with a diameter of 1 mm, the secondary winding of the transformer (boost) contains 450 turns of wire with a diameter of 0.4 mm.

As the magnetic circuit of the transformer, a rod from a ferrite antenna of an AM receiver with a diameter of 8 mm with a magnetic permeability of 400 ... 600NN 60 mm long is used, the primary winding is wound first (58 turns), next to it a coupling coil, and a boost winding is wound through the insulating material over these coils along 150 turns in three rows, alternating insulation material.

If the lamp does not light up when power is applied, reverse the positions of the feedback coil leads. If the lamp is lit, then remove the current-limiting resistor R3 2.2 Ohm from the circuit.

Source - http://www.talkingelectronics.com/projects/FluorescentInverter/FluorescentInverter.html

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• 10.10.2014

  The figure shows a diagram of a pre-amplifier with a timbre block, the timbre block is included in the feedback circuit of the pre-amplifier. The supply voltage of the device can vary from 12 to 24V, the current consumption is not more than 10 mA. The input signal comes through the blocking capacitor C1, the resistors R1 and R2 determine the bias voltage of the transistor VT1, after preliminary amplification ...

• Here is another design using a 555 microcircuit. The device is a DC-AC voltage converter, which is designed to power energy-saving lamps from low voltage. Input voltage range 8-18 Volts (optimal 12 Volts). An alternating voltage is generated at the output of the transformer high frequency about 400 volts. It is a simple and stable single-ended voltage converter that can be used in field trips or in a car.

  Despite its compact size and simplicity of design, the converter develops a sufficiently high power, which directly depends on the specific type of key used. With the use of a powerful field-effect transistor of the IRF3205 series, the power reaches 70 watts. In my case, an IRFZ48 transistor was used, with it the power is no more than 50 watts. It is not advised to raise the power more than 70 watts, since it will be necessary to calculate the parameters of the pulse transformer again.

  

  
  The 555 timer operates as a square wave generator. The pulses are amplified by a powerful field switch. The transistor must be installed on a heat sink. The pulse transformer consists of only two windings. The primary winding consists of 7 turns. For the convenience of winding, 3 cores of wire with a diameter of 0.5 mm each were used. This solution saves space. Further, a boost is wound over the primary winding. This winding consists of 80 turns of wire with a diameter of 0.2mm. The winding can be wound in bulk without additional insulation layers.

  

  
  The core was used from an old ATX power supply. First, you need to remove the transformer from the block board and disassemble it. The ferrite halves are firmly glued to each other, so they need to be slightly warmed up. You need to heat it carefully (with a lighter or a powerful soldering iron).

  

  
  After, you need to remove all the windings and wind the ones you need. Such a single-ended converter can power fairly powerful neon tubes up to 50 watts. The converter can also be used to supply power to other electrical devices, including those designed for constant voltage, only in this case a rectifier is needed at the output.

  
  This circuit was taken from the magazine Radiohobby No. 3 for 1999 and is a step-up voltage converter built on the principle of a blocking generator. Generation is carried out due to positive feedback, which controls the operation of the key transistor. In this case, short-time are generated on the secondary winding of the transformer. high voltage pulses... At the moment the converter is turned on, the fluorescent lamp has a high resistance, the voltage at its electrodes rises to 500 volts, but as soon as the lamp warms up, the voltage drops to 50 - 70 volts. Therefore, it is extremely important not to turn on the converter without load, since the voltage across it can rise to 1000 volts, which can damage the transformer.
  

  

  
  The figure shows two circuits, the top one is for a transistor p-n-p structures, lower - for transistor n-p-n... Naturally, when the structure of the transistor is changed, the polarity of the capacitor C1 also changes.

  The transformer is manufactured on W-shaped ferrite 7x7 with magnetic permeability НМ2000. The secondary winding is wound first, according to the scheme it is connected to the LDS. It contains 240 turns wound with PEV-0.23 wire. After that, the winding is well insulated and the collector winding is wound over it - these are 22 turns wound with a PEV-0.56 wire and a base winding that contains 6 turns wound with a PEV-0.23 wire. Naturally, wire diameters can vary within small limits. The core required for the transformer being manufactured can be obtained in an old rotary telephone set, for example, TA-68. Then all old windings must first be removed from its frame. Also, the W-shaped core of a suitable section of the magnetic circuit can be taken from computer unit nutrition. Important! A gap is required between the halves of the W-shaped core - a spacer made of non-magnetic material. A sheet of thin paper, one layer of electrical tape, etc. will do. This is necessary so that the core does not become magnetized, otherwise the converter will stop working after a short time.

  For correct operation of the circuit, it is necessary to adjust the current consumed by the converter. To do this, you need to know the power of the applied LDS. Let's say its power is 20 watts. Then the current consumed by the converter should be 20W / 12V \u003d 1.66A. This current is set by selecting the base resistor R1.

  Transistor T1 must be placed on the radiator. The area of \u200b\u200bthe radiator is chosen in such a way that after an hour of work it would be possible to hold on to it calmly. Instead of transistors KT837F and KT805BM, KT818 and KT819 can be used, respectively.

  The efficiency of the converter is checked as follows. If, immediately after turning on the converter, the lamp lit up dimly, and after a split second it flared up in full force, then everything is working normally. If the lamp continues to work dimly, then it is necessary to select R1, or even change the transistor. The wires from the transformer to the lamp should be as thick and short as possible, otherwise the lamp will ignite poorly, or not at all.

  And now some photos.
  

  

  

  

  

  Your attention is presented voltage converter circuit (electronic ballast) for power fluorescent lamp (LDS) from an autonomous source with a voltage of 12 V. The basis of the circuit is square wave generatorcollected on timer NE 555 .

  Pulses from the generator output are fed to the key transistorVT 1 and a step-up transformer. A ready-made 220/12 mains transformer can be used as a step-up transformer, turned on in reverse (in the circuit, as you can see, 120V / 6V is recommended).

  All the same, it is advisable to make the transformer yourself, this will increase the efficiency of the converter, as well as use a lamp with a power of up to 18W. The transformer is wound on an armored magnetic core made of 2000NM1 ferrite with an outer diameter of 30 mm. Winding I contains 35 turns of wire PEV-2 with a diameter of 0.45 mm, winding II ≈ 1000 turns of PEV-2 0.16. The windings should be insulated from each other with several layers of varnished cloth. To increase reliability, winding II must be divided into several layers, laying varnish between them. The magnetic core cups are assembled with a gap of 0.2 mm and tightened with a screw and a nut made of non-magnetic material. With slightly worse results (the ratio of brightness ≈ consumed current), a transformer made on a magnetic circuit fromline transformer tv .

  Resistor R 1, it is better to put a trimmer, this will help to adjust the maximum brightness of the glow (when tuning to the resonance frequency of the secondary winding, the current consumption will decrease significantly).

  When using a homemade transformer, capacitors C3, C4 can be excluded.

  Rice.1 Voltage converter for fluorescent lamp

  Power supply of fluorescent lamps (LDS) from a 12 volt battery.

  The converter allows powering LDS with a power of up to 20 W from a car battery with a glow duration of about 60 hours. The current consumption of the device is approximately 0.75 amperes. Schematic diagram converter is shown in the figure below.

  Transformer TP1 is implemented on a Ш8х8 ferrite W-shaped core. The wire is wound by a turn to a turn with each layer of the wire wrapped with capacitor paper (instead of paper, a thin fluoroplastic tape is suitable). Pay special attention to the quality of the winding of the transformer, wind it carefully, and at the end of the procedure, in order to avoid breakdown, saturate it with epoxy resin (the resin is diluted with alcohol before impregnation).

  Winding data of transformer TP1:

  ● I winding - 30 turns of wire PEV-2 with a diameter of 0.5 mm;
  ● II winding - 12 turns of wire PEV-2 with a diameter of 0.3 mm;
  ● III winding - 500 turns of wire PEV-2 with a diameter of 0.15 mm.

  On the diagram, the dots indicate the beginning of each of the windings. Pay attention to the winding sequence:

  ● the third winding is wound first, wrapped in capacitor paper;
  ● a wire for the second winding is connected to the beginning of the first winding and it is wound in the opposite direction, then a layer of paper or fluoroplastic tape;
  ● the third winding is wound with subsequent impregnation.

  To prevent thermal breakdown of the transistor, it should be installed on a radiator, which can be made independently from sheet aluminum. The area of \u200b\u200bthe radiator plate must be at least 20 cm2. The parameters of the KT863 transistor are shown in the figure below.

  The SW1 button, which closes the circuit of the capacitor C4, is necessary to start the LDS, but, as a rule, after the power is supplied to the LDS converter, it lights up immediately.

  After assembling the converter, before turning on, make sure that there are no installation errors again, connect the lamp and apply voltage to the device. The lamp should light up. If the lamp does not light up, and the SW1 button does not help, check the transistor for serviceability, if the transistor is serviceable, re-place the terminals of the first winding, the generator should start working.

  Homemade neon lights car bottom.

  Fans of all kinds of "mulek", "fenech", and other automobile bells and whistles, along with decorating the interior of their car, get to the bottom of the body, they like when, driving through the evening city, their bolivar glows like christmas tree.
  Of course, in our time in stores you can buy all kinds of ready-made car "gadgets", including illumination of the underbody, but the price sometimes does not suit everyone. Therefore, craftsmen have to put their hands to make such a "luminary" with their own hands.

  Below we present to your attention a simple, repeatable converter circuit capable of lighting fluorescent lamps with a power of 20 to 40 watts when the device is powered from a 12 volt car battery.

  

  It should be noted that the purpose of this converter for LDS lamps is not limited to the illumination of the underbody. It can be used as a backup lighting device when the main power supply is cut off (emergency lighting), a portable low-voltage lamp can be made for use in all kinds of trips (trips to the forest or fishing, camping with an overnight stay, etc.). In general, the thing is useful, it remains only to sculpt it, since the circuit of the device is rather primitive and details are not scarce for it. The only thing you need to pay attention to is the quality of the winding of the transformer, which, unlike the previous version described above, is wound on a ferrite rod with a diameter of 8 mm, and the length is about 5 - 8 cm.

  And so how to wind the transformer:

  ● We take a ferrite core of the size we need, wind a layer of thin, well-sticky (better imported) electrical tape on it;
  ● We wind the high-voltage winding III as follows: we take a coil of wire with a diameter of 0.2 - 0.3 mm and to the end we solder a piece of a multicore, which will serve as a tap, apply it to one edge of the ferrite wrapped with a layer of electrical tape, and wind tightly a turn to the turn one layer of winding until filling the length of the ferrite. Apply one layer of electrical tape to this layer of winding. We continue to wind in the opposite direction also over the entire length of the ferrite core. We also cover the second layer of winding with a layer of electrical tape. Thus, we wind the entire high-voltage winding. For lamps from 8 to 16 watts, the winding contains 600 ... 700 turns, for lamps from 20 to 40 watts - wind 100 more turns.

  

  ● It remains to wind the primary and secondary windings. They wind alternately in one direction as shown in the diagram (the dots indicate the beginning of the windings), and do not forget to lay a layer of insulating tape between these windings. The wire diameter allowed for winding the primary and secondary windings is 0.5 ... 1.2 mm (it is better to choose something in between). The primary winding contains 25 turns, the secondary - 45 turns.

  

  In the process of assembling the device, do not confuse where which winding is, this is fraught with the fact that your LDS will not burn (at best), or the transistor of the converter will "crack" (at worst).

  What else can I say about the assembly ...

  Diode KD226 can be replaced with any other "current" (ampere by 3) diode, for a voltage of at least 50 volts, or some imported one with similar parameters (for example FR607 - current 6A, 1000 volts). Below, for reference, see the characteristics of KD226 and select the appropriate one if you do not have the one indicated in the diagram.

  Resistors R1 and R2 it is better to put not half-watt, as in the diagram, but one-watt, especially R2, because in the process of work they tend to warm up. The selection of these resistors sets the required current consumption of the converter (0.6 ... 0.8A), which determines how brightly the lamp will glow. It is not worth increasing the current consumption, the difference in brightness with a further increase in the current will not be large, and the transistor will be turned on at the same time “Mama don’t worry…”. If, when tuning, the current is already high enough, and the LDS still does not want to shine normally, it is better not to chase the consumption current, but try to increase or decrease the capacitance of the capacitor C1, its capacity can be steered within 0.05 ... 0.5 microfarads.

  Resistance R1 is selected depending on the power of the lamp that you plan to use, its rating can be in the range of 430 Ohm ... 2kOhm. For example, when using an LDS with a power of 8 watts, R1 will be about 2 kOhm, and with an LDS of 30 ... 40 W - within 360 ... 820 Ohms.

  Transistor KT805AM installed on a radiator, it can be made of sheet aluminum, with a cooling area of \u200b\u200babout 100 cm2. Better yet, run the finished device for an hour, and then check how much the transistor has heated up. Slightly lukewarm means it will live normally. Yes, and the quality of the lamp glow depends on the transistor, with one LDS it may not light up confidently, but with the other the same it lights up immediately, although both transistors are in good order. The table below shows the parameters of the KT805 transistors. Replacement for KT819G is possible.

  How to check the operation of the converter:

  ● Be sure to connect the lamp (do not supply power to the inverter without a lamp connected, and also do not disconnect the lamp while the inverter is running);

  ● Power up the inverter. LDS first lit up dimly, and after a second it burns brightly - everything means good.

  ● If your luminary is lit up dimly, and a glow is observed along one edge of the LDS, try to increase Ipotr, if the current consumption is normal, change VT1 to another.

  ● Do not make too long the length of the wires connecting the lamp to the converter, and do not take too thin a wire for this purpose, it depends on how well the LDS will ignite, and whether it will light up at all.

  ● And one more way to check the converter: carefully slide the wires from the high-voltage winding to a gap of about 5 ... 10 mm. If a trailing spark jumps in this gap, then the device is working. If not, shorten the wires, the number of turns of the high-voltage winding is not enough, or change VT1.

  

  Attention!!! Be careful when adjusting the converter, there is a high voltage on the 3rd winding of the transformer when the power is supplied to the circuit, of course, it will not kill, but it can “shibanut” - it will not seem a little. Observe electrical safety measures.

  Underbody lighting lamps.

  In general, such lamps are produced not only with a white glow, they are also pink, blue and green. Lamps of T4 standard and a power of 20 watts are quite enough for these purposes. For example, you can use F20W T4 BLUE, this lamp is blue. The dimensions of this lamp: length - 57cm, diameter - 1cm.

  Before attaching the lamp to the underbody, wires are connected to its contacts, and it is placed in a transparent PVC tube. The length of the tube is chosen by 8 ... 10 centimeters longer than the lamp, so that it is possible to fill the ends of the tube with liquid nails, and attach the luminary to the body or frame for the remaining free areas using self-tapping screws.

  

  PS. Part ratings (R1, R2, C1) are best selected for each specific lamp. If the converter is set up at home when operating from a power supply, ensure that the LDS is ignited confidently at a voltage of 11 volts. When set to Upit \u003d 13V, and the subsequent installation of the device on a car, the lamps may glow poorly even when using wires with a cross section of 0.75mm.