|
(5) Photo-Cells / Photo-Transistors 4000:1 Dark:Light Resistance Ratio Use in light activating circuits. Give your robot the gift of sight. Make an automatic light dimmer. These Photo-Cells are light sensitive photo-transistors. Actual resistance ratio will depend on light level, applied voltage and series resistance. These variables are not critical. A good start would be 12 VDC (32 V max) applied through a 1 Meg resistor. Experimentation will be necessary to achieve the maximum L/D ratio but the suggested values are easy to achieve and will give excellent results. We used a digital ohmmeter with a 2 Meg max range to make our resistance measurements. In complete darkness, the meter went into over-range. With a bright LED, the resistance dropped below 500 Ohms. Facing the flat surface, the left lead is negative. Note: they do respond if wired backwards, but performance suffers tremendously. If you are a musician and experimenter, build an oscillator/amp using photo-cells in the R-C timing and gain control circuits and make a THEREMIN to create those eerie wavy / warbly sounds heard in old sci-fi movies. One photo-cell to control frequency and another to control volume. Be sure to add us to your Favorites List ! 14 day Non-DOA, Good-on-Arrival Guarantee Untested, but NO JUNK or suspect parts PCB parts are thru-hole, NO SMD/SMT Manufacturers may vary from picture (all content is the responsibility of the poster) |
Desiree-Navarro@oklahomaselltoday.com (Desiree Navarro) for more information. All emails will be forwarded to the poster's actual email address.