Suggested by a 90s EDN, this circuit supports almost any LED as a source and a phototransistor as a detector. The circuit operates with a PLL 567 at a frequency of around 40 kHz.
This fixed regulator for currents up to 2 A uses a 741 operational amplifier. The transistor must...
Using a zener diode it is possible to change the linearity of the scale of an analog instrument by...
This high sensitivity circuit was found in the July 1992 Radio Electronics magazine. The circuit...