Alarm with relay (CB21218E)

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

Common Emitter PNP Relay (CB25611E)
This relay shield was found in the October 1993 Electronics Now magazine. The circuit is powered by...
Regulator 12 V x 1 A 723 (CB14529E)
In the figure we have the basic configuration of a regulator for 12 V x 1 A suggested by Motorola in...
Sound Detector 741 (CB17585E)
This circuit can be used as part of a Vox project or as an input shield for a microcontroller that...