Alarm with relay (CB21218E)

This latching alarm circuit using relays was found in American documentation. Sensors are connected in parallel.

Tone control (CB12770E)
The base of this circuit is 1/4 of an integrated circuit 4136 which consists of a quadruple 741....
Phase shift oscillator (CB20438E)
This circuit has a common configuration widely used in projects on this site. The transistor is...
555 Linear Ramp Generator (CB6357E)
This circuit appears elsewhere in this section and on this site. The circuit generates a linear...