This voltage converter is designed to generate 220 volt mains voltage from 12 volts DC, although it also works perfectly well with a reduced voltage source down to 8 volts. Power can be increased to 100 watts using an IRF3205 reverse conductivity field effect transistor. A car battery serves as the power source.
The converter is based on the UC3845 microcircuit, using a slightly modified Waldemar circuit. Specifically, the nominal values have been modified, which allows for stable operation.
The device’s housing is an ignition unit from a car’s xenon headlights.
The transformer is based on an E-shaped core from an ATX power supply. The primary winding is wound with two conductors, containing six turns of wire, each 1 mm in diameter. The secondary winding contains 100 turns of wire with a diameter of 0.5 – 0.7 mm.
The diode is replaced with a KD512; ultra-fast diodes like the SF309 or similar can be used. The resistor has a resistance of 820 ohms and a power rating of 2 watts. The transistor should be mounted on a heat sink. The design is quite simple, even for a beginner. I believe this is the simplest 12-220 V converter that can produce this kind of power. Moreover, the transformer has only two windings without any taps, which is precisely why beginners often get confused about the winding phasing.
List of radioelements
| Designation | Type | Denomination | Quantity | Note | Shop |
|---|---|---|---|---|---|
| PWM controller | UC3845 | 1 | Search the Otron store | ||
| Q1 | MOSFET transistor | IRL3705N | 1 | Search the Otron store | |
| D1 | Diode | KD512A | 1 | Search the Otron store | |
| C1 | Capacitor | 3300 pF | 1 | Search the Otron store | |
| C2 | Electrolytic capacitor | 4700 μF 16 V | 1 | Search the Otron store | |
| C3 | Electrolytic capacitor | 10 μF 16 V | 1 | Search the Otron store | |
| C4 | Capacitor | 22 nF | 1 | Search the Otron store | |
| C5 | Capacitor | 470 nF | 1 | Search the Otron store | |
| R1 | Resistor | 6.8 kOhm | 1 | Search the Otron store | |
| R3 | Resistor | 5.1 kOhm | 1 | Search the Otron store | |
| R5 | Resistor | 820 Ohm | 1 | Search the Otron store | |
| Tr1 | Transformer | 1 | see diagram | Search the Otron store | |
| BAT1 | Battery | 12V | 1 | Search the Otron store | |
| Switch | 1 | Search the Otron store |