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 90s Radio Electronics. The transistor can be any general purpose....
The circuit below shows how to obtain a monostable from a CMOS 4013 flip-flop. The actuation time...
This circuit is from Philips' 60s documentation. The circuit can be applied to modern operational...