Found in an Analog Devices manual from the 1990s, this circuit can employ any operational amplifier.
We find this circuit in an old documentation, but it can be implemented with modern equivalent...
This circuit eliminates transients that are 10% above the zener voltage. The transistor must be in...
A solution for using more than 6 channels in a tone-modulated system that uses LM567 as decoders, is to...