The tone generated by this bell changes when we press and release the switch. The circuit is from a 1985 Radio Electronics. Some changes can be made to improve its performance.
This simple metal finder uses a 100 uA indicator. The exploration coil must be constructed in a...
This resistance meter has a linear scale, converting resistances to voltage. The operational...
This circuit was found in a 1995 documentation. Its purpose is to indicate voltage levels that are...