Flasher CA3130 (CB22004E)

Found in an English documentation from 1977, this flasher or pulser circuit drives an LED. The frequency depends on C2.

Bicycle Speed Alarm (CB13735E)
This circuit was found in an American magazine in 1978. It activates a relay when the speed of a...
Salen Key Low Pass Filter (CB4865E)
This second-order low-pass Salen-Key filter was obtained from an American 1980s documentation. Formulas...
Siren with Touch Sensor (CB23790E)
The circuit shown in figure 1 generates an intermittent tone in a piezoelectric transducer when...