This crowbar circuit for alternating current causes a quick fuse to blow when the load current exceeds a certain value. The circuit is from an American 80's documentation.
This circuit was found in a Popular Electronics from the 90s. The counter circuit is not common...
This circuit lights up a warning LED (tilt) when a device in which the mercury key is located is...
This circuit is based on an old operational amplifier, having been found in documentation from the...