This circuit is from American documentation from the 1980s. The transistors are general purpose types and the relay can be 6 or 12 V depending on the supply voltage.
This simple diode test appears at other points in this section. Or circuit can be adapted to use...
Found in Electronics Now magazine in an issue from the 90s, this circuit is different from the...
This circuit inverts the phase of an audio signal, maintaining its intensity. The transistors can...