This circuit was found in Motorola documentation from 1966. The lamps are according to power and current according to the components used which are uncommon today.
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...