Phone circuit (CB8709E)

With this circuit, found in a 80s Popular Electronics, it is possible to use two ordinary phones in a basic intercom.

Strobe (CB19291E)
This xenon lamp circuit is from old documentation. The trip transformer has a 1: 1 turn ratio and...
2 kHz Alarm (CB4877E)
This simple alarm with integrated CMOS sounds a piezoelectric transducer when the sensor circuit...
4060 Crystal Oscillator with Divider (CB4620E)
In the figure we have an interesting circuit for those with a project that requires a sub-multiple...