This circuit triggers an alarm in the event of a power failure. The circuit is from an 80's documentation, being powered by 9 V battery. The parts are common today.
This circuit was found in a Popular Electronics of the 90s. The resistor R4 determines the load...
Obtained from a 1980s Signetics documentation, this circuit uses a common integrated circuit at the...
We found this circuit in the Linear Applications Handbook by National Semiconductor. The circuit is...