This circuit was found in an Electronic Design from the 90s. The circuit uses a type J thermocouple that can measure from -50 to + 100º C. Power is provided by a 3 V lithium battery.
This circuit indicates through LEDs when an automotive fuse is open. ...
This is a project that can easily be adapted for other purposes such as counting people, objects,...
This frequency-corrected 1 kHz circuit has a nearly perfect rectangular signal. The circuit is...