Undervoltage detector with the LM3900 (CB25172E)

The figure shows how to implement an undervoltage detector using a Norton amplifier and a zener diode as the main elements.

Direct shield for triac (CB5185E)
This shield circuit was found in an American publication from the 80's. The triac is of low...
White Noise Generator (CB12081E)
In this circuit of a 1978 publication, the noise generated at the collector-base junction of any...
Metronome or Electronic Drum (CB10001E)
This circuit is from a year 2000 documentation. It generates pulses as fast as a battery or as...