This sound intensity meter was found in a 90s Elektor. The circuit uses an integrated device from the time that is not common today. The indicator is a milliammeter.
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...