This circuit is from a Popular Electronics from the 90s, consisting of a repeater relay for remote control of TV, which today can be done by Wi-Fi or other simpler resources.
This circuit works both as a preamplifier and activates a relay when speaking in front of the...
This simple CMOS touch switch with bistable action must not be powered by a source without a...
This circuit activates an incandescent lamp (it cannot be of another type) when it gets dark. The...