Flood alarm (CB7994E)

This circuit is from a 90s Popular Electronics. The transistors are of general use and the buzzer is a Sonalert type.

IR Modulated Transmitter (CB856E)
This circuit produces a IR beam with a frequency adjusted by the 100k pot. The circuit can be used in...
Telephone Scrambler (CB23524E)
This voice scrambler and descrambler circuit was found in a Radio Electronics from July 1963....
0 to 15 V x 7A power supply (CB17368E)
This transistor source was found in a 1990 documentation. 2N3055 transistors must be equipped with...