We found this circuit in the March 1999 issue of Electronics Now magazine. The indicator used is an analog type. The values indicated depend on the calibration.
I found this circuit in an English publication from 1989. This configuration can be mounted with...
This circuit triggers a buzzer or other warning device when the light falling on the sensor is cut...
The power of this small amplifier reaches 75 mW per channel depending on the voltage and the load...