This circuit consists of a stereo audio compressor. We found it in Radio Electronics magazine from October 1968. The circuit uses an opto-coupler made with a neon lamp and LDR.
This circuit can be used in a single optical link or optical communication system and even using an...
This current meter with many scales was found in a 80s American documentation. The operational amplifier...
Large-surface diodes and even neon lamps can function as radiation sensors. The circuit shown in...