The core of the Car DC to DC Converter 12V to ± 38 VDC is a pulse generator built on the TL494 chip. The circuit is designed to provide power supply to Monoblock Car Amplifier TDA7294. Generator frequency can be changed by varying the resistor R3. Optionally, you can download the datasheet and find out more details on chips.
All resistors (except R4, R9, R10) is 0.25 W, you can even enggunakan 0.125 Watt, R9, R10 – 2W, R4 – you can use an 1W (or 0.5 W). Diode VD1 is placed at the entrance to protect against reverse polarity, is eliminated. Choke L1 in my case, wound on a ferrite ring with a diameter of about 2 cm from the computer power supply. It contains 10 turns double wire 0.8 mm in diameter that are distributed around the ring. This reactor can also be wound on a ferrite rod diameter 8-10mm and a length of 2-3cm. Probably the most difficult in the converter is the correct construction of the transformer, because it is very dependent on the ability of the unit overall. For sample in this Car DC to DC Converter 12 V to ±38 V project transformer wound on a ferrite ring marked 2000 NM size 40 * 25 * 11.