Using the LM170 integrated circuit, this circuit was found in the May 1970 Radio Electronics magazine. The transistor is general-purpose, and the potentiometer adjusts the gain.
This circuit can source up to 1,000 V from a 9 V battery. Output current is very low, some...
The National Semiconductor LM675 operational amplifier can provide up to 3 A of output current. In the...
This circuit is for traditional old-style telephone lines found in an American 1980s...