Slave flash (CB8700E)

This circuit was found in a Popular Electronics from the 90s. It uses a LASCR which is a photo-SCR not common today.

Manually triggered VCO (CB19082E)
The CMOS 4046 integrated circuit is not very common today, consisting of a very efficient PLL for...
Automatic Telephone Recorder (CB5992E)
This circuit turns on an old cassette recorder when the telephone rings, thus enabling the...
Incandescent Flasher (CB4595E)
This circuit can be used in panel signaling with common incandescent lamp. The lamp will flash at a...