This approach alarm circuit was found in the September 1970 Radio Electronics issue. The 1 mH coil is wound on a ferrite rod. The relay is 12 V sensitive.
This circuit came out in a Popular Electronics from December 1995. It is a double T configuration that...
This circuit starts a water pump at a lower level of the reservoir and then turns it off when it...
This relaxation oscillator, simulated in the Multisim Blue, produces two different signals. The...