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 protects an operational amplifier with respect to both current and voltage. The...
Other amplifiers of the series like the MC3301, MC3401 and LM2900 can be used in this circuit. We found...
This is a simple source indicated for powering low voltage projects on the bench. The circuit is...