This AC to DC converter circuit is capable of converting an alternative voltage within 70V 260V range into a DC voltage within 180V to 350V DC range, so it can be used for 110V and 220V too. To achieve this voltage conversion we use a MC34161 rectifier as a voltage doubler at low input voltages and as a classic rectifier at high input voltages. Input AC voltage/Output DC voltage table AC to DC converter circuit diagram MC34161 includes a reference power supply which delivers 2.54V at pin 1. The signal level applied at pin 2 is internally compared with a 1.27V voltage. D5 zener diode, togheter with R1 and C4 provide ICs required 12V voltage. Capacitors voltage of C2 and C3 must be greater than 250V. Attention: this ac to dc converter contains very high voltages that are deadly and you must be very careful!