This simple circuit is intended to test the zener test. RV1 can be calibrated in terms of voltage. The maximum voltage of the tested zener is that used in the circuit supply.
This circuit was obtained in a 1979 publication. The operational amplifier is of the type with...
This circuit was obtained in a 90’s Popular Electronics. The frequency depends on C1, a component...
Because it uses TTL integrated circuits, this siren must be powered by 5 V or as indicated with D1 to...