This alarm circuit with sensors in series was found in the Electronics Now magazine of June 1994. The circuit is powered according to the relay used.
This siren produces an intermitent sound given by the characteristics of the two oscillators using the...
This circuit for some amps was found in a 90s Radio Electronics. The voltage can be between 6 and 25 V...
This circuit was found in a 90s Electronic Engineering. The circuit has the tube's critical...