We found this circuit in the January 1978 issue of Radio Electronics magazine. The integrated circuit is from that time and is powered by a 9 V battery. The signal must be applied to an amplifier.
The integrated circuit used in this amplifier is not common today. The circuit is from a...
This circuit produces paced steps of an engine whose speed can be adjusted in the trimpot. The key on...
Many reed switches can be wired in series to perform na efficient alarm as shoen in the figure....