This circuit was found in an 80's EDN. The circuit uses a current common CMOS, the 4093 powering an LED. Trigger adjustment is done in a trimpot.
This is a multi-component tester with visual indication by LED and polarity selection in the test....
This circuit is from a 1978 operational amplifier manual. The power supply must be symmetrical, and the...
This circuit is stabilized by a thermistor or NTC with a resistance between 2 and 5k. The signal is...