This circuit is from a 90s American documentation. The circuit can use complementary pairs according to the power. The power voltage can be between 5 and 12 V.
This amplifier was found in a Japanese publication in 1972. Transistors are uncommon today, and...
The current of this source is 200 mA at the most, and the output depends on the zener that may...
Found in Mallory documentation from 1968 this circuit uses an integrated circuit from that time. The...