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.

TIP31 and TIP32 1W Amplifier (CB25709E)
This small audio amplifier was found in the May 1994 issue of Electronics Now magazine. The power...
Audio Relay (CB13614E)
The displayed relay operates with an audio signal applied to the input. The transistors can be...
Photodiode Amplifier 1 (CB13092E)
The circuit shown in the figure and uses the diode in the leakage current operation mode. In it,...