This circuit is from American documentation from the 1980s. The circuit can make use of any common NPN transistor and the power comes from two small batteries.
This solid-state relay (SSR) or shield was found in a 1995 Electronics Now. The transistor can be...
The output current of this circuit reaches 12 mA. The zener diode determines the output voltage. The...
In the figure we have an IF amplifier step using a MOSFET. The circuit was found in a 1980s...