We found this circuit in an English publication from the 60's. The transistors are of germanium of the time and the headphones must be high impedance magnetic.
This interesting automotive alarm was found in a 90's Popular Electronics. The circuit uses...
Found in a 90s Popular Electronics, this circuit allows Interfacing electronic applications with the...
This circuit was obtained in a Motorola manual from 1978. We can use any triac and the coupler with...