Led phototheraphy circuit

While doing a research across the web, I notice the topic about phototherapy. It says that exposure to a light at specific wavelength is be...

Infrared Remote Control Tester

This is a fairly easy circuit that can be used to test TV and VCR remote controls. The infrared detector module (GP1U52X) (Radio Shack 276...

Decibel Meter

The circuit below responds to sound pressure levels from about 60 to 70 dB. The sound is picked up by an 8 ohm speaker, amplified by a tra...

AC Line Current Detector

This circuit will detect AC line currents of about 250 mA or more without making any electrical connections to the line. Current is detect...

Touch Activated Light

The circuits below light a 20 watt lamp when the contacts are touched and the skin resistance is about 2 Megs or less. The circuit on the l...

Low Frequency Sinewave Generators

The two circuits below illustrate generating low frequency sinewaves by shifting the phase of the signal through an RC network so that osc...