Found in a Popular Electronics from the 1990s, this circuit monitors the voltage of a power supply or battery. The trigger voltage is adjusted with a potentiometer.
This circuit is from an old Japanese magazine from 1960. The circuit uses germanium transistors from the...
This is the factory setting (National Semiconductor) of the TDA2006 as an audio amplifier. The...
This circuit can use a pendulum sensor. We found this configuration in a 1994 publication. The...