This simple Bargraph photometer with 4 LEDs was found in a 1997 documentation. The scale is adjusted in a trimpot and the sensor can be any common LDR. Power can be supplied by cells or battery.
We find this ultra-simple transmitter circuit that is nothing more than a very short range RF...
Found in an American documentation from 1968, this circuit senses the temperature through an...
The integrated circuit used in this circuit is from the time of publication. The circuit is from a...