This simple three-LED sensor uses an NTC at the input. The circuit is based on an uncommon integrated component today. We found it in documentation from the 80s.
The resistors R determine the frequencies of the oscillator together with C. The circuit is from a...
This circuit can be used as shield or to drive powerful loads from low current switches such as...
Two of the four gates of a 4011 is used in this biestable touch circuit. Do not use a power source...