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Dark activated switch - started this project with the idea to build a simple
single-ended tube amplifier. I didn't have any experience with the construction of
tube amps so I was looking for a beginner's project. Such a project should be simple
(for easy debugging) and it should
(electroninc design added 04/05/06) |
Dark Activated Switch (Andy Collinson) - This circuit will activate a relay when
light falls to a preset level. Light level can be adjusted with VR1 and the relay
contacts may be used to operate an external light or buzzer.
.(schematic added 03/04/05) |
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Dark Sensitive Switch - Dark Sensitive Switch is a simple project which
operates a relay when the light falling on the LDR goes below a set
point.
.(circuit design added 08/08) |
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Dark-activated 230V Lamp - Compact circuitry using small-size parts only.
Can be wired in parallel to existing switches. (added 3/05) |
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Dark-activated LED or Lamp Flasher - This circuit adopts the rather unusual
Bowes/White emitter coupled multivibrator circuit. The oscillation frequency is
about 1Hz and is set by C1 value
..(electronic design added 6/07) |
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Dark-activated switch needs only three components - 07/23/09 EDN Build a
dark-activated switch with only a triac, a photocell, and a resistor.....(design
idea added 08/09) |
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Dark-Detecting LED Circuit - Here's a simple problem: "How do you make an LED turn
on when it gets dark?" You might call it the "nightlight problem," but the same sort
of question comes up in a lot of familiar situations-- emergency lights, street
lights, silly computer keyboard backlights, and the list goes on. Solutions? Lots. The
time-honored tradition is to use a circuit with a CdS photoresistor, sometimes called
a photocell or LDR, for "light-dependent resistor.".
.(design added 11/08) |
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Day & Night Infrared Detection - (circuit design added 8/03) |
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Demodulator Makes Low Cost Optical Tracker - 06/18/98 EDN-Design Ideas: (design
idea added 2/06) |
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Digitally control room light intensity - 11/11/04 EDN-Design Ideas: Many people
favor different light and temperature settings for different rooms depending upon
their mood or whether they are working or relaxing. The circuit in Figure 1 controls
the intensity of the artificial light in a room and monitors the temperature of two
zones. The two main circuit blocks are the PIC16C67 master controller and the ADT7516
temperature-sensor interface, which includes a.....(design idea added 11/05) |
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FET Input High Speed Light Detector - This circuit is yet another design that
converts current from a PIN photo diode to a voltage. It has a bandwidth that extends
beyond 50MHz.
.(designed by David A. Johnson) |
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High-speed lightwave component analysis - Aligent Application Note 1550-6
(added 4/08) |
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Honeybee Counter - I designed a circuit similar to this one a long time ago to
help a beekeeper count the number of bees going into or out of a hive. The low power
circuit uses a slotted opto-sensor to detect the passing bees. The circuit advances an
electronic counting module whenever a honeybee passes through the sensor. The device
only counts the number of bees going through the sensor. A different circuit would be
needed to count the number of bees only going out or only coming into the hive.
.(designed by David A. Johnson) |
