This is a precision half-wave rectifier, suggested by Texas Instruments. Diodes are commonly used, and resistors can have signal values. The power supply must be symmetrical.
S-meter is a signal strength meter used in radio transmission. Also known as Strength meter, in this...
By connecting several photocells in series, we can directly activate a sensitive relay, as shown in...
This circuit was found in a recent English publication, making use of a power transistor that...