This circuit is from a 1980s Motorola documentation. The circuit makes use of old components that can in some cases be exchanged for modern equivalents.
This circuit is from a 1995 technical documentation. The transistor can be a BC558 and the sensor...
Found in a Popular Electronics from the 90s, this circuit checks the presence of voltage on a...
The critical component of this amplifier is the output transformer. We found the circuit in an old...