741 Based Light Sensor: CdS photocell used for light/dark
controlled relay |
Basic Infrared Light Train Detection:
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Battery Powered Sensor Detects Dangerous U Volt Radiation:
12/08/94 EDN-Design Ideas |
Block Occupancy Detector Helper: |
Dark / Light Activated Relay: |
Dark Activated Switch or Porch Light Switch: |
Darkness monitor : |
Day and Night Infrared Detection: |
Demodulator Makes Low Cost Optical Tracker: 06/18/98 EDN-Design
Ideas |
Infrared to Light Converter: This circuit converts infrared
light into sound. Modulated Infrared light, like that ROM remote
controls, Infrared received by the phototransistor and is
amplified by the LM386 IC. |
Laser Pointer Train Detector: |
Latching light detector is frugal with power and parts:
09/26/2002 EDN - Design Ideas / This idea demonstrates three
uses for the humble LED. The circuit in Figure 1a forms a simple
light detector that latches and turns on an LED when the ambient
light exceeds a preset limit determined by potentiometer P1. LED
D1 is both the indicator. |
Light / Dark Detector: |
Light Detector #1: |
Light Detector #2: |
Light Direction Sensor: |
Light Intensity
Sensor: Logarithmic amplifier uses the log caracteristic of
PN (diode, transistor) to implement logarithmic function. The
second transistor is used as refference and with the PTK
resistor minimizes the dT/dV coeficient. |
Light
Pollution Meter : LED brightness control circuit and a
multimeter to compare light levels to LED level.
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Light Sensing RF Transmitter: |
Light Sensor Adapter for Oscilloscope: |
Light Sensor With Hysteresis: |
LIGHT/DARK ACTIVATED RELAY: This is actually two circuits a
light activated relay being the first and a dark activated relay
being the second, once again all components and values are
displayed in the gif image. |
Matched Diode Pair Improves Performance Of Linear Optical Sensor
: 05/27/02 Electronic Design - Ideas for Design /
Hand-marked cards for applications like voting machines and
meter readers often have dark marks, light marks, erasures, or
dirt. Digital systems can't distinguish between an intended
mark, dirt, or erasure because they have a single preset
threshold.... |
Optical sensor needs no tweaking: 06/13/2002 EDN - Design
Ideas / The transfer gain of optical sensors spans a 16-to-1
ratio because of variations in the LED, phototransistor, ambient
temperature, and optical path. The wide transfer-gain variation
complicates output-resistor selection in dc-coupled circuits.
You must size the output resistor to prevent high transfer gains
from causing output-stage saturation, but low transfer gains
yield low output-voltage sw.... |
Photodetector Sorts Objects: 03/04/99 EDN-Design Ideas / PDF
contains multiple circuits - scroll to find this circuit. |
Programmable Light Activated Relay: |
Pulsed Sensor Extends Battery Life: 01/01/98 EDN-Design
Ideas |
RF Transmitter, Light Sensing: |
Solar sun tracker : |
Two LEDs Perform Rudimentary Spectral Analysis: 09/01/94 EDN-Design
Ideas |
U Volt Sensitive Photodetector: |
Using The LM555 Timer With Photocell Detectors:
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Visible Light Photo Detector Circuits (E+F):
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