This circuit is from an 80's Electronic Engineering. The base is a common operating and 4 single integrated voltage comparators. The circuit directly drives 4 indicator LEDs.
Suggested by Siliconix in documentation from the 90s, this amplifier has its gain digitally...
This circuit is from Radio Electronics. The magazine no more exists, but the circuit can be...
An oscillator that uses two gates is not suitable for critical applications, as it tends to pick...