This circuit was obtained from a 90s Radio Electronics. The value of R1 determines the scale according to the table next to the diagram. The power suppley must be symmetrical.
We found this transistorized circuit in a 1985 documentation. The circuit can operate with...
This simple circuit controls the brightness of an LED from LDRs, NTCs, PTCs or other resistive sensors....
This remote control, which works by a beam of light from a flashlight, for example, can be used to...