This unusual circuit from a Popular Electronics of the 90s uses LED indicators, operating as a bridge. The components used are common. It is based on the tuning of the signal by a PLL.
This circuit, in addition to transforming a sinusoidal signal into a square, shifts its phase. The...
This transmitter, found in Raytheon documentation from 1957, has a range of a few meters. L1 can...
This circuit uses operational amplifiers that must be powered by a symmetrical source to implement a...