This circuit indicates when the voltage of a 12 V battery is low. With changes, for example, the zener, the circuit can be used to monitor other voltages.
This voltage regulator for automotive use was found in a Radio Electronics from the 80s. The Q3...
This instrument was found in a publication for radio amateurs in 1973. The tuned circuit consists of...
This circuit is found in a 2005 Linear Technology application manual. The circuit monitors the High...