Found in an Electronic Design from the 90's, this circuit measures the equivalent resistance in series of a resistor. The circuit operates at 50 kHz producing a rectangular signal.
The sensor for this alarm is an LDR and it consists of an oscillator that goes into action when...
We found this amplifier circuit for inductive audio pickups in a documentation from the 70s. The...
This circuit is from an American documentation from 1976. The FET can be the BF245 or MPF102 and...