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.
In the figure we present an interesting application suggested by Microchip (www.microchip.com) in which the voltage...
With the capacitor used, this circuit provides delays of 40 to 60 seconds. Larger capacitors can...
This circuit was published in a 1981 magazine, but it can be easily assembled, as all components are...