This is one of the many 7400 oscillators we have in our circuit bank. It is crystal controlled and must be powered with a voltage of 5 V.
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...