Sawtooth generator (CB21338E)

This op amp circuit is based on a 555 IC and two common op amps. Transistors are general purpose.

Varicap Spy Transmitter (CB19433E)
This circuit with variable capacitance diode (varicap) is from a publication from the 90s. The...
Divider by N with the 4017 (2) (CB12131E)
With this circuit it is possible to divide the frequency of a rectangular signal by values between 2...
Triac driver (CB22446E)
The presented circuit uses an optocoupler to trigger a triac. We found it in a Popular Electronics from...