Modulated light receiver (CB21790E)

We found this circuit in a Mullard manual from 1960. The transistor is a phototransistor of the time. The gain is 3 dB.

AC Line Interference Filter (CB452)
This filters blocks radio interference or noise coming from the AC Power line. Noise such as the...
Shutdown circuit 2 (CB8419E)
Found in a 90s Popular Electronics, this circuit triggers a relay in case of overvoltage. Can be used as a...
Alarm System (CB16793E)
We found this sophisticated home alarm in a 1994 documentation. The circuit supports sensors of...