This IR light sensor circuit was found in the July 1992 issue of Radio Electronics magazine. It is tuned for 20 kHz modulated light.
This VCO with a common operational amplifier was found in an old American documentation. The...
An way to change the frequency of the previous oscillator (CIR112E) is to add a variable capacitor in the...
This interesting circuit was obtained from a Poptronics of February 2001. The American magazine no...