Neon Fuse Blown Monitor (CB24104E)

This circuit was found in the January 1971 Radio Electronics magazine. It keeps the light flashing if the fuse blows.

Three-Gate Ring Oscillator (CB106)
An oscillator that uses two gates is not suitable for critical applications, as it tends to pick...
Piezoelectric Alarm (CB6425E)
We found this circuit in a 1991 Hobbyst Electronics. The circuit makes use of an unusual...
Integrated Intercom (CB16336E)
We found this circuit in a 1982 documentation. An intercom to be good must be sensitive and have...