This circuit was found in the July 1992 issue of Radio Electronics magazine. The circuit is based on a 741 that activates a buzzer with oscillator. R5 adjusts the sensitivity.
This overcurrent relay was obtained in a documentation from the 90's. The sensor consists of a...
We found the circuit for this commercial radio in Japanese documentation from the 1960s. The...
This mixer configuration with the 741 operational amplifier can be found on several other circuits in...