The power is of the order of 20 W, depending on the efficiency of the transformer used, which makes the circuit interesting in feeding devices that are not sensitive to the input waveform such as shavers, incandescent lamps, etc.

   Power transistors shall be provided with heat radiators. The transformer has 12 + 12 V secondary with a current of 3 A. Transformers with smaller currents can be used but we will have a lower power output as well.

   The TTL oscillator integrated circuit must be powered with 5 V, voltage which is supplied by a 7805 regulator. Since only one IC is powered it will not be necessary to use a heatsink on the regulator. Tracks driven by the most intense currents must be wider.

   The 2N3055 power transistors should be mounted on good heat radiators, preferably on the outside of the enclosure that will house the assembly.

 

Semiconductors:

CI-1 - 7400 - TTL integrated circuit

CI-2 - 7805 - 5 V voltage regulator

Q1, Q2 - BD135 - medium power NPN transistors

Q3, Q4 - 2N3055 - Power NPN transistors

D1, D2 - 1N4148 - Silicon diodes

 

Resistors: (1/8 W, 5%)

R1, R2 - 1k ohms

R3, R4 - 120 ohms

C1, C2 - 4.7 uF x 12 V - electrolytic

C3, C4 - 10 uF x 16 V – electrolytic

 

Several:

T1 - Transformer - see text

Printed circuit board, wires, solder, heat radiators, etc.

 

Datasheets


N° of component