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Ssensors / Detectors: Light Detectors and Optical Sensors  
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Light Detectors / Optical Sensors:   #'s - D       E - L       M - S       T - Z

 

Last Updated: November 22, 2021 03:00 PM

Circuits Designed by Dave Johnson, P.E. :
PV Solar Panels-Ideal Blocking Diode Circuit -  Solar panels usually include a diode at their outputs.  The diode prevents current from back feeding into the panel at night from the battery being charged by the panel.  But, this diode does waste some power and does reduce the available panel voltage . . . Hobby Circuit designed by David Johnson P.E.-March, 2011

Reduce voltage to Photovoltaic Solar Panel with Ideal Diode -  Solar panels usually include a diode at their outputs.  The diode prevents current from back feeding into the panel at night from the battery being charged by the panel.  But, this diode does waste some power and does reduce the available panel voltage. . . Circuit by David Johnson P.E.-March, 2011

Remote Extender Circuit -  This circuit is designed to be placed directly in front of a standard TV or VCR remote.  The exiting light pulses produced by the circuit match the pulses from the remote but are about 10 times more powerful.  Using the device, the remote can operate a TV or VCR over three times the normal distance. . . Circuit by David A. Johnson P.E.-June, 2000

RFID Test Circuit -  I designed this test the concept of using light techniques to send identification data instead of RF. . . . Hobby Circuit designed by Dave Johnson P.E.-February, 2002

Safety Light -  My 1200 square foot metal shop only has one small entrance door and no skylights.  if the lights are turn off while inside, there is not enough light to safely find the door to exit the building.  On a couple occasions, while I was quietly working at my test bench, my wife would walk into the shop, grab a garden tool and rush back out, turning off the lights and closing the door without thinking . . . Hobby Circuit designed by David Johnson P.E.-November, 2004

Salvaged Broken Solar Cells -  As illustrated below, one way to salvage a large number of broken solar cells is to wire them in parallel, not in the more conventional series connection.  Broken cells of various sizes and shapes are grouped together into panels of about one quarter to on . . . Hobby Circuit designed by David Johnson P.E.-January, 2012

Modulated Light Receiver uses a Single IC -  The circuit uses a very inexpensive C-MOS IC that is connected to a small photodiode.  Using a unique inductive feedback network, the circuit provides high sensitivity under high ambient light conditions.  it is a great circuit when you want to extend the range of an optical remote control transmitter . . . Hobby Circuit designed by David Johnson P.E.-June, 2000

Shop Safety Light -  My 1200 square foot metal shop only has one small entrance door and no skylights.  if the lights are turn off while inside, there is not enough light to safely find the door to exit the building.  On a couple occasions, while I was quietly working at my test bench, my wife would walk into the shop, grab a garden tool and rush back out, turning off the lights and closing the door without thinking . . . Hobby Circuit designed by Dave Johnson P.E.-November, 2004

Simple Circuit for White LED Night Light -  This simple circuit is designed to plug into a standard AC electrical outlet.  it uses four super bright white light emitting diodes (LED) in conjunction with a capacitor coupled full wave rectifier circuit. . . Circuit by David A. Johnson P.E.-July, 2003

Single IC forms Senesitive Modulated Light Receiver -  The circuit uses a very inexpensive C-MOS IC that is connected to a small photodiode.  Using a unique inductive feedback network, the circuit provides high sensitivity under high ambient light conditions.  it is a great circuit when you want to extend the range of an optical remote control transmitter. . . Circuit by David A. Johnson P.E.-June, 2000

Slotted Opto-Sensor used in 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 . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2000

Slotted-Type Optical Interrupter Draws Microamps -  This circuit is great for battery-powered systems that use slotted type optical interrupters.  it draws only 10uA from a 3v battery that should allow up to 5 years of operation from a lithium battery . . . Hobby Circuit designed by David A. Johnson P.E.-June, 2000

Snow Depth Alarm -  The design of this system alerts a snowplow driver when the snow depth has exceeded four inches.  A visible red LED packaged in a 10mm package is pulsed at a rate of about 50Hz with 10uS pulses.  Twenty four inches away a phototransistor detects the light from the LED.  The LED and the phototransistor are housed in a section of ˝ inch PVC pipe, forming a waterproof seal. . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

Solar Cell Test Fixture -  if you are considering building your own solar panel, you might try building the solar cell tester shown below.  When constructing a solar panel it is important to make sure that all the solar cells used in the panel be closely matched for their short circuit . . . Hobby Circuit designed by David Johnson P.E.-November, 2007

Solar Insolation Monitor -  Owners of photovoltaic solar panels often like to monitor how bright the sunshine is.  They can use this information to gage how well their solar panels are doing.  On a typical clear day, the sun energy at sea level is about 1000 watts per square meter . . . Hobby Circuit designed by Dave Johnson P.E.-May, 2012

Solar Lithium Ion Battery Charger using LT1132 -  I have been designing a number of solar powered devices lately.  Many of them use just a single 3.6v lithium ion battery.  These batteries like to be charged from a fixed 4.2v source with a charging current limited to about C/8, where C is the milliamp-hour rating of the part. . . Circuit by Dave Johnson P.E.-December, 2012

Solar Path Light Improvement -  Use the circuit below was designed to replace the guts of an existing path light assembly with one which has a much better performance.  I suggest using a quality 10 cell solar panel with at least a 4 square inch area.  Buy a panel with solar panels that. . . Circuit by David Johnson P.E.-March, 2011

Solar Powered Cell Phone Charger -  The simple circuit below regulates the voltage from a 6v solar panel to a fixed +5v.  That voltage can be fed to any cell phone or USB connected portable device, to charge its battery.  The circuit uses a Reg113-5 voltage regulator from Texas instruments. . . Circuit by David Johnson P.E.-January, 2011

Solar Powered Flood Light using NiMH Cells -  There are many solar powered garden lights available.  Most of the devices offered at the home improvement stores have very poor performance.  Their batteries are too small, the light launched is weak and the solar panels are undersized.  None of the devices I have tested would operate through a typical night. . . Circuit by David Johnson P.E.-December, 2013

Solar Powered Infrared 1W Security Camera Illuminator -  Many security cameras are equipped with an array of infrared LEDs to illuminate an area in front of the camera with invisible light for night time surveillance.    However, there are times when a remote area, well away from the camera, needs additional infrared light.    The circuit below uses a modified solar powered path light to bathe a fairly large area with 850nm infrared light. . . Circuit by David Johnson P.E.-June, 2014

Solar Powered Lithium Ion Battery Charger -  The circuit below feeds a controlled current and voltage to a 3.6v lithium ion battery.  The current is limited to 300ma and the voltage is limited to 4.2 volts.  The circuit uses a LTC1734 IC from Linear Technology.  No diode is needed between the circuit a . . . Hobby Circuit designed by David A. Johnson P.E.-May, 2007

Solar PV Cell Test Fixture -  This is an illustration of a test fixture, which can be used to test individual solar cells for short circuit current.  Using a PIN photo diode and a control circuit, the solar cells can be tested under constant light level conditions. . . Circuit by David Johnson P.E.-October, 2006

Solar-Powered Pump Motor Controller -  A Discover Circuits visitor had a problem.  He needed a simple on/off controller for his solar powered water pump.  His system used two 12v 50 watt solar panels wired in series.  The power from the solar panels drove a submerged water pump.  However, during. . . Circuit by David A. Johnson P.E.-October, 2010

Capacitance Proximity Switch
Draws very low power - Ideal for battery-powered applications
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Links to electronic circuits, electronic schematics and designs for engineers, hobbyists, students & inventors:

Red LEDs Function as Light Sensors -  03/20/08  EDN-Design idea    You can build simple LED illuminators using the red LED to sense ambient-light level Design by Geoff Nicholls, Glinde, Germany

Reduce voltage to Photovoltaic Solar Panel with Ideal Diode -  Solar panels usually include a diode at their outputs.  The diode prevents current from back feeding into the panel at night from the battery being charged by the panel.  But, this diode does waste some power and does reduce the available panel voltage. . . Circuit by David Johnson P.E.-March, 2011

Relay: Dark Activated -  This circuit switches a relay at dark via a Light Dependent Resistor or LDR for short.  The applications are numerous.  in my application, it switches on a light with an older type movement sensor and is mounted on the top corner of my workshop with the LDR __ Designed by Tony van Roon  VA3AVR

Remote Extender Circuit -  This circuit is designed to be placed directly in front of a standard TV or VCR remote.  The exiting light pulses produced by the circuit match the pulses from the remote but are about 10 times more powerful.  Using the device, the remote can operate a TV or VCR over three times the normal distance. . . Circuit by David A. Johnson P.E.-June, 2000

RF Transmitter Light Sensing -  This transmitter is very simiilar to the Simplest RF Transmitter.   The only difference being the photoresistor placed in series with R1.   This could also be a thermistor or other variablwe resistance sensor. __ Designed by Tony van Roon  VA3AVR

RFID Test Circuit -  I designed this test the concept of using light techniques to send identification data instead of RF. . . . Hobby Circuit designed by Dave Johnson P.E.-February, 2002

Safety Light -  My 1200 square foot metal shop only has one small entrance door and no skylights.  if the lights are turn off while inside, there is not enough light to safely find the door to exit the building.  On a couple occasions, while I was quietly working at my test bench, my wife would walk into the shop, grab a garden tool and rush back out, turning off the lights and closing the door without thinking . . . Hobby Circuit designed by David Johnson P.E.-November, 2004

Salvaged Broken Solar Cells -  As illustrated below, one way to salvage a large number of broken solar cells is to wire them in parallel, not in the more conventional series connection.  Broken cells of various sizes and shapes are grouped together into panels of about one quarter to on . . . Hobby Circuit designed by David Johnson P.E.-January, 2012

SCC3 12V 20A Solar Charge Controller -  The SCC3 kit is the heart of a 12 Volt solar power system, it regulates the charging of batteries from photovoltaic (PV) solar panels.  A charge controller is an essential part of any solar power system.  A 12 Volt solar power system can provide power to a wide variety of devices such as lighting systems, Ham and CB radios, car stereos, cell phone chargers, laptop computers, televisions, recording equipment, fans, water pumps and other 12V DC loads.  With the addition of a DC to AC inverter, the DC power can be converted to 120 Volts AC for running many household electronic devices. 
 __ Designed by G. Forrest Cook

Screamer Siren-Light Controlled -  This circuit will produce an ear-piercing scream, depending on the amount of light being detected by the Light Dependent Resistor.  __ 555-Timer

Sensing Light -  A light sensor project from CHiPAXE. __ Contact Jameco Electronics

Modulated Light Receiver uses a Single IC -  The circuit uses a very inexpensive C-MOS IC that is connected to a small photodiode.  Using a unique inductive feedback network, the circuit provides high sensitivity under high ambient light conditions.  it is a great circuit when you want to extend the range of an optical remote control transmitter . . . Hobby Circuit designed by David Johnson P.E.-June, 2000

Sferics Detector -  "Sferics" (also spelled "spherics") is short for atmospherics and refers to the crackling static in a radio produced by lightning.  This receiver is tuned to an unused portion of the LF band provides enough sensitivity to detect lightning activity for hundreds or even thousands of miles.  Best performance is achieved with an external antenna, but just a few yards of insulated wire is sufficient.  A short whip mounted on the unit will work fine for picking up local storms. __  Contact:  Charles Wenzel of Wenzel Associates, Inc.

ShadoW Alarm -  This shadow alarm circuit can sense a moving shadow in a confined area.  it can be used to protect things from theft.  When somebody approaches the unit, it will give a loud alarm to abort the attempt of theft.  The circuit uses the light sensing property of the Photo diode.  The circuit uses the light sensing property of the PIN __ Designed by D Mohankumar

ShadoW Sensor Alarm -  Shadow sensors are widely used to detect the movement of a person in a confined area.  Many circuits published earlier have a serious drawback that only one light dependent resistor (LDR) is used for shadow detection.  Needless to say, this is not a perfect solution!  Shadow Sensor Circuit Schematic Described here is a simple but __ Designed by T.K. Hareendran

Shop Safety Light -  My 1200 square foot metal shop only has one small entrance door and no skylights.  if the lights are turn off while inside, there is not enough light to safely find the door to exit the building.  On a couple occasions, while I was quietly working at my test bench, my wife would walk into the shop, grab a garden tool and rush back out, turning off the lights and closing the door without thinking . . . Hobby Circuit designed by Dave Johnson P.E.-November, 2004

Simple Circuit for White LED Night Light -  This simple circuit is designed to plug into a standard AC electrical outlet.  it uses four super bright white light emitting diodes (LED) in conjunction with a capacitor coupled full wave rectifier circuit. . . Circuit by David A. Johnson P.E.-July, 2003

Simple Circuit light Sensoradapter for Oscilloscope -  This circuit is a simple visible light or IR detector for testing any equipment which outputs light. The circuit can be also used for measuring ambient light levels.  This circuit is based on one photodiode which is used in photocell mode so that the photodiode generates a voltage and current signal when it get light.   __ Designed by Tomi Engdahl

Simple Circuit Night-Light Uses a Photoresistor to Detect Dusk -  12/15/11 - Design ideas - You can adjust this battery-powered circuit for different levels. Design by Chau Tran, Analog Devices, Malden, MA

Single IC forms Senesitive Modulated Light Receiver -  The circuit uses a very inexpensive C-MOS IC that is connected to a small photodiode.  Using a unique inductive feedback network, the circuit provides high sensitivity under high ambient light conditions.  it is a great circuit when you want to extend the range of an optical remote control transmitter. . . Circuit by David A. Johnson P.E.-June, 2000

Single microcontroller pin senses Ambient light, controls illumination -  26-Oct-06 EDN Design Ideas:  LED circuit senses light and controls its own brightness Design by Loren Passmore, Berkeley, CA

Slotted Opto-Sensor used in 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 . . . Hobby Circuit designed by David A. Johnson P.E.-July, 2000

Slotted-Type Optical Interrupter Draws Microamps -  This circuit is great for battery-powered systems that use slotted type optical interrupters.  it draws only 10uA from a 3v battery that should allow up to 5 years of operation from a lithium battery . . . Hobby Circuit designed by David A. Johnson P.E.-June, 2000

Snow Depth Alarm -  The design of this system alerts a snowplow driver when the snow depth has exceeded four inches.  A visible red LED packaged in a 10mm package is pulsed at a rate of about 50Hz with 10uS pulses.  Twenty four inches away a phototransistor detects the light from the LED.  The LED and the phototransistor are housed in a section of ˝ inch PVC pipe, forming a waterproof seal. . . . Hobby Circuit designed by David Johnson P.E.-July, 2006

Solar Cell Test Fixture -  if you are considering building your own solar panel, you might try building the solar cell tester shown below.  When constructing a solar panel it is important to make sure that all the solar cells used in the panel be closely matched for their short circuit . . . Hobby Circuit designed by David Johnson P.E.-November, 2007

Solar Insolation Monitor -  Owners of photovoltaic solar panels often like to monitor how bright the sunshine is.  They can use this information to gage how well their solar panels are doing.  On a typical clear day, the sun energy at sea level is about 1000 watts per square meter . . . Hobby Circuit designed by Dave Johnson P.E.-May, 2012

Solar Lithium Ion Battery Charger using LT1132 -  I have been designing a number of solar powered devices lately.  Many of them use just a single 3.6v lithium ion battery.  These batteries like to be charged from a fixed 4.2v source with a charging current limited to about C/8, where C is the milliamp-hour rating of the part. . . Circuit by Dave Johnson P.E.-December, 2012

Solar Path Light Improvement -  Use the circuit below was designed to replace the guts of an existing path light assembly with one which has a much better performance.  I suggest using a quality 10 cell solar panel with at least a 4 square inch area.  Buy a panel with solar panels that. . . Circuit by David Johnson P.E.-March, 2011

Solar Powered Cell Phone Charger -  The simple circuit below regulates the voltage from a 6v solar panel to a fixed +5v.  That voltage can be fed to any cell phone or USB connected portable device, to charge its battery.  The circuit uses a Reg113-5 voltage regulator from Texas instruments. . . Circuit by David Johnson P.E.-January, 2011

Solar Powered Flood Light using NiMH Cells -  There are many solar powered garden lights available.  Most of the devices offered at the home improvement stores have very poor performance.  Their batteries are too small, the light launched is weak and the solar panels are undersized.  None of the devices I have tested would operate through a typical night. . . Circuit by David Johnson P.E.-December, 2013

Solar Powered Infrared 1W Security Camera Illuminator -  Many security cameras are equipped with an array of infrared LEDs to illuminate an area in front of the camera with invisible light for night time surveillance.    However, there are times when a remote area, well away from the camera, needs additional infrared light.    The circuit below uses a modified solar powered path light to bathe a fairly large area with 850nm infrared light. . . Circuit by David Johnson P.E.-June, 2014

Solar Powered Lithium Ion Battery Charger -  The circuit below feeds a controlled current and voltage to a 3.6v lithium ion battery.  The current is limited to 300ma and the voltage is limited to 4.2 volts.  The circuit uses a LTC1734 IC from Linear Technology.  No diode is needed between the circuit a . . . Hobby Circuit designed by David A. Johnson P.E.-May, 2007

Solar PV Cell Test Fixture -  This is an illustration of a test fixture, which can be used to test individual solar cells for short circuit current.  Using a PIN photo diode and a control circuit, the solar cells can be tested under constant light level conditions. . . Circuit by David Johnson P.E.-October, 2006

Solar-Powered Pump Motor Controller -  A Discover Circuits visitor had a problem.  He needed a simple on/off controller for his solar powered water pump.  His system used two 12v 50 watt solar panels wired in series.  The power from the solar panels drove a submerged water pump.  However, during. . . Circuit by David A. Johnson P.E.-October, 2010

Sunrise Lamp using 120VAC 60 Watt Lamp -  in this circuit, a 120VAC lamp is slowly illuminated over a approximate 20 minute period.  The bridge rectifier supplies 120 DC to the MOSFET and 60 watt lamp.  A 6.2K, 5 watt resistor and zener diode is used to drop the voltage to 12 volts DC for the circuit power.  The bridge rectifier should be rated at 200 volts and __ Designed by Bill Bowden

Sunset Lamp -  LDR-based automatic lights flicker due to the change in light intensity at dawn and dusk.  So compact fluorescent lamps (CFLs) are unsuitable in such circuits as flickering may damage the electronic...__ Electronics Projects for You

Sun-Up Alarm -  The Sun - Up Alarm can be used to provide a audible alarm for when the sun comes up or it can be used in a dark area and detect when a light comes on.  it can also be used to detect a light beam, headlights etc.  The circuit works as follows.  The phototransistor is very sensitive to light. (Any phototransistor will work fine)  __ Designed by Randy Linscott

Super Light Sensor -  This “Super Light Sensor” responds to minute fluctuations in light level, auto-adjusting over the range from about 200 lux up to 60, 000 lux (ie, from a modestly lit room to direct sunlight).  it has lots of potential uses – eg, detecting a car entering a driveway, a person moving in a room, or wind rustling__ 

Got Designs?
Please eMail
if you want me to link to and/or post your original design Thanks.

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Light Detectors / Optical Sensors:   #'s - D       E - L       M - S       T - Z


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