Page 11 Light Dependent Resistor Electronic Circuits

Light Dependent Resistor Circuits / Photocell Circuits
Light Dependent Circuits: # - C D - H I- N O- Z

Last Updated: June 02, 2021 05:07 AM

Circuits Designed by Dave Johnson, P.E. :

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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., 03/06/11]
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., 06/04/00]
RFID Test Circuit - I designed this test the concept of using light techniques to send identification data instead of RF. A more detailed discussion on this scheme can be found in the Imagineered new products section . . . [Hobby Circuit designed by Dave Johnson P.E., 02/11/02]
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., 11/29/04]
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 Dave Johnson P.E., 01/01/12]
Sensitive 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., 06/04/00]
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., 11/29/04]
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 Johnson P.E., 07/27/03]
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., 07/08/00]
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., 06/04/00]
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 ½ inch PVC pipe, forming a waterproof seal. . . . [Hobby Circuit designed by David Johnson P.E., 07/18/06]
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., 11/25/07]

RFID Test Circuit - I designed this test the concept of using light techniques to send identification data instead of RF. A more detailed discussion on this scheme can be found in the Imagineered new products section . . . [Hobby Circuit designed by Dave Johnson P.E., 02/11/02]

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., 11/29/04]

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 Dave Johnson P.E., 01/01/12]

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. . . . [No designer name given]

Sensing Light with a Programmable Gain Amplifier - Application Note Published 28-Mar-03. . . [Microchip]

Sensitive 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., 06/04/00]

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., 11/29/04]

Simple Ambient Light Sensor Circuit - Analog Devices-Analog Dialogue. . . [by Mullins, Paul]

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 Johnson P.E., 07/27/03]

Simple light Sensoradapter for Oscilloscope - . . . [Designed by Tomi Engdahl]

Simple Night-Light Uses A Photoresistor to Detect Dusk - 11/11/04 EDN Design Idea If you need to produce extremely fast pulses in response to an input and trigger, such as for sampling applications, the predictably programmable short-time-interval generator has broad uses. The circuit of Figure 1, built around a quad high-speed comparator and a high-speed gate, has settable 0- to 10-nsec output width with 520-psec, 5V transitions. Pulse width varies less than 100 psec with 5V supply variations of 65%. The minimum input-trigger width is 30 nsec, and input-output delay is 18 nsec. . . [by Chau Tran, Analog Devices, Malden, MA]

Simple Photodetector Circuit - I´ve designed this simple circuit to test a photodetector. I got the detector from an old 5 1/4" disk drive. If you can get one, you will find two photodetectorts: one is used to sense the density (double density or high density) . . .

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., 06/04/00]

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., 07/08/00]

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., 06/04/00]

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 ½ inch PVC pipe, forming a waterproof seal. . . . [Hobby Circuit designed by David Johnson P.E., 07/18/06]

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., 11/25/07]

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Links to electronic circuits, electronic schematics and designs for engineers, hobbyists, students & inventors:

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., 03/06/11]

Rejects Ambient Light - 06/10/99 EDN Design Idea In some applications, you need to detect light signals in the presence of background light whose intensity can change by orders of magnitude. The circuit in Figure 1 uses an integrated photodiode/amplifier (OPT201) in. . . [by Massimo Gottardi, IRST, Trento, Italy]

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., 06/04/00]

Light Dependent Resistor Circuits / Photocell Circuits
Light Dependent Circuits: # - C D - H I- N O- Z