Silent Alarm (CB6444E)

This circuit simply triggers an LED when the sensor is activated. The circuit is from a Popular Electronics of the 90s.

| Clique na imagem para ampliar |

Sound Optical Transmitter (NI016E)
This transmitter is modulates a infrared light source from an audio signal. Applications include a...
Rumble filter (CB6541E)
This turntable filter was found on an 80's Elektor. The circuit makes use of operational features...
Audio Mixer with LM741 (CB25928E)
This circuit is from a Radio Electronics magazine from May 1989. The power supply must be...