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.

Automotive Tachometer (CB13706E)
This circuit was obtained in a 1975 documentation. It is intended for old vehicles that still use...
Transistor gain test (CB20734E)
With this circuit it is possible to select transistors and their compliant test. Or circuit...
Variable Power Supply with Selector (CB24588E)
This power supply circuit with selectable voltages was found in the June 1979 issue of Radio...