Low Voltage Test (CB22158E)

This is a simple voltage tester for voltages from about 2V to about 15V with the indicated resistor and red LEDs.

Automatic Headlight Switch 555 (CB24403E)
This circuit was found in February 1976, Radio Electronics magazine. The circuit is powered by 12 V...
Digital Low Pass Filter (CB13621E)
This circuit was obtained in a 1973 publication, being implemented with TTL technology. The...
One Million Hour Indicator (CB6698E)
Found in a 1969 documentation on neon lamps, it actually takes advantage of the durability of the neon...