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.
The amplifier shown in the figure was obtained from the Anlog Devices linear integrated circuits...
If the reader still uses silk screen printing tables this is an interesting circuit found in a 1994...
This circuit monitors the output of a stereo amplifier, checking the balance and balance between...