Electronic Circuits of the Week January -June 2010

DiscoverCircuits.com, has 28,000+ electronic circuits, cross-referenced
into 500+ categories. We have searched the web to help you find quick design ideas.
We make every effort to link to material posted by the designer.
Please let us if you would like us to link to your design.

HOME

Schematics

Discover Forum

Hobby Corner

Dave's Circuits

Electronic Resources

Book Corner

Contact Info

Imagineering Ezine

Discover Solar Energy

Dave Johnson &
Associates

My eBay Auctions

Faraday Touch Switches

Circuits of the Week - 2010, July - Dec
Last Updated on: 09/02/2010 05:47 AM

2010: Jan-June July-Dec 2009: Jan-June July-Dec 2008: Jan-June July-Dec
2007: Jan-June July-Dec 2006: Jan-June July-Dec 2005: May-Dec

Aug 29, 2010

Light Monitor 2
The circuit below takes advantage of a low power op amp with a “rail to rail” feature. The single resistor R1 defines the light sensitivity of the circuit. The output voltage is directly proportional to the intensity of light striking the small photodiode D1. In total darkness, the output voltage will hover near zero volts. The capacitor C1 is chosen to filter our most AC components of the light but by decreasing its value to just a few picofarads, the circuit can operate in the tens of kilohertz range. A faster op amp will be needed for higher speed signals.