This fast Schmitt trigger operates at frequencies from 10 Hz to 100 Hz, with very short rise time. The circuit is from an American documentation from 1968.
Found in documentation from the 90s, this circuit can employ other comparators in the series such as...
This circuit was found in a PE Hobbyst Handbook from 1992. The second oscillator is a VFO. The...
This motor control using transistors was found in a recent English publication. The circuit is for...