We find this circuit in an old documentation, but it can be made using modern transistors. The circuit trips, producing a continuous sound when the sensor is wet. The 1 mOhm resistor is actually 1 Mohm.
Under this name, the popular electronic magazine of major/June 1969 introduced a simple...
This circuit was found in a 90s Radio Electronics. The FM encoder or multiplexer is an uncommon...
Found in an American publication from 1968, this circuit generates pulses at a rate of 2,500 per...