This circuit, which controls both the temperature and the level of a liquid in a reservoir, was found in an Electronic Design from the 90s. The circuit is based on a double 555.
We found this circuit in an American documentation from the 60's. The transistors are made of...
The accuracy of this circuit depends on adjustments made with capacitors of small tolerances of known...
The figure shows how to implement an OR function with two inputs, using a relay. The relay...