Solar flashlight (CB20488E)

This circuit charges a battery to power a flashlight at night. The circuit is from an English publication from 1991.

RMS to DC Converter (CB6105E)
This circuit was suggested by Signetics in 1980s documentation. The circuit makes use of the...
Sinusoidal Oscillator (MSB013E)
This circuit produces low frequency sinusoidal signals. The circuit is a phase shift oscillator...
Pulsing Tone Alarm (CB4878E)
This variation of the previous circuit produces a pulsating sound when the sensor is activated. The...