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 circuit can be used as a shield when its supply is 5 V. in this case we can exchange the...
This reflectometer or standing-wave ratio meter (SWR) was found in a 1980s American documentation. The...
This circuit is from Motorola's 1990 Linear Databook. The integrated circuit used is no longer...