Astable 555 (CB21101E)

This 50% duty cycle configuration was found in a Popular Electronics from the 1990s. The operating frequency is given by C1.

Photoelectric alarm (CB22336E)
Found in a publication from the 60's, this circuit uses the CK722, germanium transistor of the...
Ramp Generator (CB16917E)
From an input signal, and using an unusual current source, this circuit generates a ramp, that is, a...
Common Load Timer (CB17040E)
With this timer we can start between 30 seconds and one and a half seconds, time set in the pot....