Low battery indicator 555 (CB9551E)

This circuit can operate with different voltages, depending on the zener used. We found it in a 90s American documentation.

Lamp Control (CB20533E)
This circuit, which in our times would be called a shield, can also be used with other loads. The...
Relay Drive (CB13907E)
This circuit is from an old American documentation from the 70s. Transistor 2N3904 can be replaced by...
Signal Injector with 555 (CB25532E)
This application of the 555 was found in the November 1992 Radio Electronics magazine. The...