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 found this version of the automotive tachometer in a 1980s publication. Variations from other...
This circuit was obtained from American documentation from 1966. It triggers when the two input...
This circuit allows to increase the output power of a 741 as an amplifier. The circuit is from a...