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Detailed entries for one subject from the INDEX TO HOW TO DO IT INFORMATION.
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The entries are in alphabetical order by magazine name and then in chronological sequence.
To obtain a copy of any magazine article contact your local public library or the publisher.


A computer controlled stepper motor light scanner. A scanning sensor capable of detecting both infrared and visible light can be used as part of an alarm system. It will detect and then track the source of the light. May have application in light-seeking robots.
BYTE Nov 1978 (v.3#11) pg. 76
Correction BYTE Jan 1979 (v.4#1) pg. 53

Adjustable threshold temperature alarm and light-detection alarm circuits.
COMPUTERS & ELECTRONICS Apr 1983 (v.21#4) pg. 109

Wireless remote control circuit uses a beam of light to control model trains or boats or other electrical devices.
CQ. THE RADIO AMATEUR'S JOURNAL Apr 1979 (v.35#4) pg. 102

Circuits for a (1) proximity detector and (2) light sensor incorporate a light-to-voltage converter chip.
CQ. THE RADIO AMATEUR'S JOURNAL Sep 1993 (v.49#9) pg. 86

Light alarm unit produces a noticable audio tone when the unit's photocell is subjected to a reasonably high level of light. Circuit can be modified to sound alarm if light level falls or decreases below a certain level.

Photoelectric switch turns television sound off and on.
ELECTRONICS ILLUSTRATED Sep 1964 (v.7#5) pg. 38

Theory and simple projects using photocells, both photoconductive and photovoltaic types.
ELECTRONICS ILLUSTRATED May 1966 (v.9#3) pg. 83

Photosensitive devices. Learn to use photoconductive cells, photodiodes, and phototransistors in practical light-controlled circuits.
ELECTRONICS NOW Jul 1992 (v.63#7) pg. 63

This photocell-activated signal device with an audio output can be used to monitor signal lights on the front of electronic equipment when you are behind the equipment making adjustments, thus eliminating the need for a mirror or a second person.
ELECTRONICS WORLD Aug 1968 (v.80#2) pg. 76

Description of how a photocell works and typical applications.
ELEMENTARY ELECTRONICS Nov-Dec 1968 (v.7#2) pg. 59

Photoelectric alarm monitors ambient light in a photographic darkroom. When light rises to an unsafe level the alarm goes off, sounding a bell or cutting electrical power. Can be modified for other purposes (burglar, fire, freezing, ...).
ELEMENTARY ELECTRONICS Mar-Apr 1969 (v.8#1) pg. 59

Cyclops. Circuit using the Optolinear IC can be used in a burglar alarm, automatic doorbell, target for a light gun, etc.
ELEMENTARY ELECTRONICS Mar-Apr 1979 (v.19#2) pg. 37

Remote control will kill the TV sound with a blink of a flashlight.
ELEMENTARY ELECTRONICS Mar-Apr 1979 (v.19#2) pg. 43

Garage parking aid circuit. Wall-mounted photocells detect your automobile headlights and tell you when your car is centered in the available space.
HANDS-ON ELECTRONICS Sep-Oct 1986 (v.3#5) pg. 25

Photo alarm circuit causes a relay to be tripped as light levels rise or fall.
HANDS-ON ELECTRONICS Sep-Oct 1986 (v.3#5) pg. 26

Circuit enables you to know when a lamp goes out for any reason, including a burn-out or a fuse blow.
HANDS-ON ELECTRONICS Jul 1987 (v.4#7) pg. 93

Electronic wake-up call is turned on whenever light is detected. Use as an alarm clock or a novelty gadget.
HANDS-ON ELECTRONICS Oct 1987 (v.4#10) pg. 92

Light detector circuit is used to trip a relay to open a garage door, turn on an appliance, etc.
HANDS-ON ELECTRONICS Nov 1987 (v.4#11) pg. 93

Light-sensitive alarm circuit (annunciator) sounds an audio alert whenever someone enters a door.
HANDS-ON ELECTRONICS Nov 1987 (v.4#11) pg. 95

Automate your porch, driveway, or outdoor lights without generating radio-frequency interference (RFI). This photoelectric switch allows for trimming the triggering light intensity, and can power multiple devices.
HANDS-ON ELECTRONICS Jan 1988 (v.5#1) pg. 41

Electronic Tattletale monitoring circuit keeps a constant vigil on any pilot or indicator lamp. An alarms sounds whenever the lamp turns on-or-off.
HANDS-ON ELECTRONICS Jan 1988 (v.5#1) pg. 84

Light-triggered circuit. Use as a light sensor or as a simple continuty tester.
HANDS-ON ELECTRONICS Feb 1988 (v.5#2) pg. 84

Using op-amp comparator circuit chips to detect and measure real-world conditions. Circuits for monitoring temperature, light level, voltage, etc.
HANDS-ON ELECTRONICS Aug 1988 (v.5#8) pg. 62

Photocell detector circuit costs less than $1.
MODEL RAILROADER May 1996 (v.63#5) pg. 111

Circuit for a photocell switch that will shut off TV commercials using the beam of a flashlight.
MODERN ELECTRONICS [1] Feb 1978 (v.1#1) pg. 74

Sun-powered alarm. By positioning a photocell at the bottom of a long, dark tube you can cause the sun to activate the alarm only when it is exactly over the opening of the tube. Est. cost: under $11.
MODERN ELECTRONICS [1] Jun 1978 (v.1#4) pg. 58

Totally passive intruder alarm measures the reflected light from any constant illumination source as it reflected off a black surface. Should the light level go up, an alarm is sounded. Est. cost: Under $9.
MODERN ELECTRONICS [1] Jul 1978 (v.1#5) pg. 55

Circuit to turn small motors on and off in response to a light beam. Use to control model trains or toys. Est. cost: under $9.
MODERN ELECTRONICS [1] Sep 1978 (v.1#7) pg. 36

How to get started in electronics. Part 1: Inside semiconductors. Looks at the diode, transistor, SCRs, LEDs, light detectors, etc.
MODERN ELECTRONICS [2] Oct 1984 (v.1#1) pg. 44

Build this wireless remote pause control for your VCR. Use a flashlight to activate and shut off from anywhere in a typical room. Est. cost: $10.
MODERN ELECTRONICS [2] Oct 1984 (v.1#1) pg. 80

Experimenting with the analog comparator, a special circuit incorporating the operational amplifier. Circuits include (1) an adjustable light-dark detector, (2) adjustable-threshold temperature-controlled relay, (3) a sine- to square-wave converter, and (4) a peak-voltage detector.
MODERN ELECTRONICS [2] Feb 1985 (v.1#5) pg. 62

A pilot-lamp beeper. Audibly alerts you when an electrical appliance with a pilot lamp is left on. Powered by a 9-volt battery. Requires no connection to the pilot lamp circuit.
MODERN ELECTRONICS [2] May 1985 (v.1#8) pg. 48

Tips on using self-focusing photodiodes. Possible uses include barcode reading, document scanning, etc.
MODERN ELECTRONICS [2] Jun 1985 (v.1#9) pg. 72

Teleguard. Part 3. Solid-state sensing modules. Low-cost circuits you build to enhance the operation of the Teleguard security system. Includes light-activated sensors, temperature-sensing module, and fluid-detecting module.
MODERN ELECTRONICS [2] Aug 1985 (v.2#2) pg. 56

Audio amplifier experiments. Includes construction of a simple audio amplifier, underwater hydrophone, light-sensor/amplifier combinations, and a basic "photophone" system.
MODERN ELECTRONICS [2] Apr 1986 (v.3#4) pg. 66

Surface-mount-device circuits: A design and construction guide. Projects include using SMCs (surface-mountable components) to produce a subminiature LED tone transmitter, A/D converter LED bargraph or metering circuit, and light-sensitive oscillator (probe).
MODERN ELECTRONICS [2] Feb 1987 (v.4#2) pg. 40

Photo sensor operating-status indicator. Use a Darlington phototransistor to monitor a remote LED or lamp. The on-off status is displayed on this monitor by means of an LED and/or an audible signal. Useful when troubleshooting a variety of interconnected devices, each with its own set of status lights.
MODERN ELECTRONICS [2] Nov 1988 (v.5#11) pg. 32

How to detect ultraviolet, visible and infrared radiation. Part 1. Experimenting with thermister, thermopile and pyroelectric detectors.
MODERN ELECTRONICS [2] Oct 1989 (v.6#10) pg. 48

How to detect ultraviolet, visible and infrared radiation. Part 2. Photodetectors, photoemissive detectors, etc.
MODERN ELECTRONICS [2] Nov 1989 (v.6#11) pg. 46

Applications of photocells.
POPULAR ELECTRONICS [1] Mar 1964 (v.20#3) pg. 72

Photocell circuits. (1) One-transistor photocell circuit. (2) Two-transistor photocell circuit.
POPULAR ELECTRONICS [1] Mar 1964 (v.20#3) pg. 73

Very sensitive electronic relay for use in alarms, controls, etc.
POPULAR ELECTRONICS [1] Nov 1965 (v.23#5) pg. 57

Bistable photoresistive switch is activated by a flashlight. One flash of light turns it on and it remains on until another flash turns it off.
POPULAR ELECTRONICS [1] Dec 1969 (v.31#6) pg. 55

Photocell demonstrator. Relays operated by photo-cell driven amplifiers, apply and remove power from the motor.
POPULAR ELECTRONICS [1] Jun 1970 (v.32#6) pg. 46

Switch can be operated by a light beam from remote locations of up to 30 feet.
POPULAR ELECTRONICS [1] Mar 1971 (v.34#3) pg. 70

The in-out annunciator can detect which way the object was moving which broke the beam of light. Est. cost: $20.
POPULAR ELECTRONICS [1] Apr 1971 (v.34#4) pg. 48

Circuit designed to switch 240 watts with a change in light levels. Used to operate an aquarium heater.
POPULAR ELECTRONICS [1] Aug 1971 (v.35#2) pg. 88

Headlight-operated garage door or light switch. Simple circuit is powered by 9-volt battery. Trips relay to operate door or light. Sensitivity can be adjusted.
POPULAR ELECTRONICS [1] Mar 1973 (v.3#3) pg. 33

Build a light probe. This electronic device will help a blind person locate a source of light such as pilot lights, the sun or even wave forms on an oscilloscope. Produces an audio signal with frequency proportional to the amount of light striking photocell.
POPULAR ELECTRONICS [1] Mar 1973 (v.3#3) pg. 42

TV commercial killer. Flashlight beam shuts off unwanted TV sound using this circuit.
POPULAR ELECTRONICS [1] Jul 1973 (v.4#1) pg. 69

Solid-state photocells for hobbyists. Part 1. What goes on inside light-sensitive semiconductors.
POPULAR ELECTRONICS [1] Jun 1974 (v.5#6) pg. 48

More circuits using the 555 IC timer include (1) tone generator, (2) code practice oscillator, (3) CW monitor and (4) electric-eye annunciator.
POPULAR ELECTRONICS [1] Jul 1974 (v.6#1) pg. 50

Solid-state photocells for hobbyists. Part 2. How light-sensitive semiconductors are used in practical circuits.
POPULAR ELECTRONICS [1] Jul 1974 (v.6#1) pg. 64

A look at the RCA CA3062 Photo Detector and Power Amplifier IC. Some suggested circuits and tips on using the IC in light-activated controls, alarms, door openers, etc.
POPULAR ELECTRONICS [1] Apr 1975 (v.7#4) pg. 66

Low-cost remote control of appliances and lights. A flashlight beam turns a circuit on and off. Will handle up to 450 watts. Est. cost: $19.
POPULAR ELECTRONICS [1] May 1975 (v.7#5) pg. 46

Light-controlled oscillator circuit provides an audible signal which changes in pitch with different light levels. Might be used as a "seeing aid" for the blind.
POPULAR ELECTRONICS [1] Jun 1975 (v.7#6) pg. 65

Simple circuit cuts off TV sound when you shine a flashlight on a sensor.
POPULAR ELECTRONICS [1] May 1976 (v.9#5) pg. 26

Turn up to 350 watts of ac power on-or-off in response to light level using this photocell, transistor-diode ac power control system. Three sensors provide for a kind of "combination lock" to prevent children from activating dangerous electrical appliances. Sensors are concealed in artificial flowers in this example.
POPULAR ELECTRONICS [1] Aug 1976 (v.10#2) pg. 50

Photoelectric sensor. An in/out detection system counts events (up and down) and can be used to control lights, appliances, etc. Can count up to 9, 99, 999, or higher.
POPULAR ELECTRONICS [1] Jan 1977 (v.11#1) pg. 48
Added Info POPULAR ELECTRONICS [1] Aug 1977 (v.12#2) pg. 6

Photo switch can be activated by a flashlight. Uses an op amp in the circuit.
POPULAR ELECTRONICS [1] Feb 1977 (v.11#2) pg. 47

Circuit for a remote light-operated switch.
POPULAR ELECTRONICS [1] Feb 1977 (v.11#2) pg. 68

Photoelectric switch turns electrical equipment on-or-off when a flashlight beam hits the photocell.
POPULAR ELECTRONICS [1] Apr 1977 (v.11#4) pg. 57

The photoresistor. How it works and some typical circuits including a light meter, analog/digital converter and light-activated relay.
POPULAR ELECTRONICS [1] Jun 1977 (v.11#6) pg. 90

Circuit for an inexpensive electric eye. Est. cost: $3
POPULAR ELECTRONICS [1] Jul 1977 (v.12#1) pg. 92

Build a field disturbance sensor for security. Alarm device detects light changes within its field of view.
POPULAR ELECTRONICS [1] Nov 1977 (v.12#5) pg. 60

Eavesdropping on light. A look at detectors and amplifiers for monitoring modulated light sources.
POPULAR ELECTRONICS [1] Mar 1979 (v.15#3) pg. 80

Circuit for ambient light compensation for a photosensor circuit.
POPULAR ELECTRONICS [1] Jan 1980 (v.17#1) pg. 91

Simple circuit can function as either a light detector or a dark detector and sound alarm when appropriate.
POPULAR ELECTRONICS [1] Feb 1980 (v.17#2) pg. 113

Build an optical motion detector alarm that detects motion through light changes. Use as a burglar alarm, plus a smoke and fire detector.
POPULAR ELECTRONICS [1] May 1980 (v.17#5) pg. 61

Wireless switch uses a beam of infrared light to shut off television commercials (video and/or sound) for a preset period (30 or 60 seconds). Est. cost: $69.
POPULAR ELECTRONICS [1] Feb 1981 (v.19#2) pg. 44

Open-humidor alarm. Circuit sounds an alarm if exposed to light for more than a few seconds. Use to remind someone to replace the top on a humidor.
POPULAR ELECTRONICS [1] Mar 1981 (v.19#3) pg. 92

Build a "smart" light controller for a greenhouse. Turns grow lights on and off as needed, depending upon the amount of sunlight being received.
POPULAR ELECTRONICS [1] May 1981 (v.19#5) pg. 67

An appliance "off" reminder. Low-cost project uses a phototransistor to produce an audible alert whenever an appliance indicator light goes off.
POPULAR ELECTRONICS [1] Jun 1981 (v.19#6) pg. 76

Two circuits use a 7490 TTL decade counter and photocell to count people coming and going through a door.
POPULAR ELECTRONICS [1] Mar 1982 (v.20#3) pg. 102

TV commercial zapper is connected in series with the speaker wire. A light beam interrupts the signal to the speaker.
POPULAR ELECTRONICS [2] Nov 1989 (v.6#11) pg. 24

Window generator circuit can be used as a light or dark detection circuit, temperature monitor, rain detector, etc.
POPULAR ELECTRONICS [2] Jan 1990 (v.7#1) pg. 25

Ultra-simple remote-activated AC control circuit is triggered by a brief flash from an ordinary flashlight.
POPULAR ELECTRONICS [2] Feb 1990 (v.7#2) pg. 28

Digital electronics course. Light-controlled monostable applications. Combining the basic monostable multivibrator with a light-controlled comparator.
POPULAR ELECTRONICS [2] Apr 1990 (v.7#4) pg. 77

How to salvage large metal-encased transistors. You might be able to repair the transistor or use its light-sensitive properties in a photoelectric device.
POPULAR ELECTRONICS [2] Oct 1990 (v.7#10) pg. 25

Electronic aids for the blind. (1) Liquid-level indicator for a cup or glass. (2) Light probe turns light into sound.
POPULAR ELECTRONICS [2] Jan 1991 (v.8#1) pg. 27

Simple circuit turns light into sound. The 555 oscillator/timer chip forms the heart of a circuit which turns on a buzzer when light strikes a photoresistor.
POPULAR ELECTRONICS [2] May 1991 (v.8#5) pg. 86

Circuit sounds an alarm for 30 seconds if it detects any light for 15 seconds. Can be used to detect an open refrigerator door.
POPULAR ELECTRONICS [2] Nov 1992 (v.9#11) pg. 76

Light detector circuit is designed to help visually-impaired persons pinpoint light sources.
POPULAR ELECTRONICS [2] Feb 1993 (v.10#2) pg. 72

Sensors made simple. The construction, characteristics and operation of commercially available sensors such as mechanical switches, magnetic switches, photocells, phototransistors, and optocouplers.
POPULAR ELECTRONICS [2] Mar 1993 (v.10#3) pg. 40

Using a single special-purpose IC (the ULN2429A fluid detector) in as many applications as possible. (1) Low-level liquid level detector. (2) High-level liquid level detector. (3) Touch-activated switch. (4) Proximity sensor. (5) Ultrasonic pest repeller. (6) Variable square-wave generator. (7) Code-practice oscillator. (8) Alarm circuit. (9) Light beam circuit (LED-emitter / phototransistor-sensor circuit).
POPULAR ELECTRONICS [2] Jun 1994 (v.11#6) pg. 76

Light detector monitors a portion of a security video-camera monitor screen for any change in light levels. Two circuits shown.
POPULAR ELECTRONICS [2] Oct 1994 (v.11#10) pg. 82

Build the Pathfinder, a navigational aid for the visually impaired. An easy-to-build, light-sensing circuit that can be used to sweep an area to locate the direction of light sources. Useful for finding windows and doors.
POPULAR ELECTRONICS [2] Oct 1995 (v.12#10) pg. 50

Electronic sensors. Circuits for a group of 5 non-moving, non-mechanical replacement sensors that are IR light operated. (1) See-through sensor. (2) Light-block sensor. (3) PLC interface. (4) Reversed PLC interface. (5) Reflective sensor.
POPULAR ELECTRONICS [2] Jan 1997 (v.14#1) pg. 68

Simple op-amp application circuits. (1) Fixed voltage reference. (2) Light-operated sensor. (3) Alarm sensor. (4) Voltage-level sensor. (5) Peak-voltage detector and hold. (6) DC motor driver and reverser. (7) Simple timer circuit to delay relay operation for up to 30 seconds.
POPULAR ELECTRONICS [2] Nov 1997 (v.14#11) pg. 62

Audible light comparator circuit uses a unique infrared light-to-frequency converter IC to measure any difference in light falling upon a photodiode.
POPULAR ELECTRONICS [2] Oct 1998 (v.15#10) pg. 64

Three light-interruption detector circuits are designed to detect when an opaque object passes between the IR source and an IR detector.
POPULAR ELECTRONICS [2] Nov 1998 (v.15#11) pg. 62

Phototransistor basics. An introduction to photosensitive devices available to the electronic designer.
POPULAR ELECTRONICS [2] Sep 1999 (v.16#9) pg. 83

Build a light activated switch.
POPULAR SCIENCE Jan 1964 (v.184#1) pg. 128

Electric eye can serve as burglar alarm and automatic doorbell. Est. cost: $10.
POPULAR SCIENCE Sep 1965 (v.187#3) pg. 100

Electric-eye alarm is so sensitive it can be triggered by a shadow.
POPULAR SCIENCE Jun 1970 (v.196#6) pg. 94

Very sensitive electric eye does not require the separate ligh-beam source of conventional electric eyes. Can use only AC powered light source within 12 or 15 feet. Has an adjustable sensitivity control.
POPULAR SCIENCE Jul 1972 (v.201#1) pg. 96

Flue bug. Low-cost electronic device warns you to close the damper on a chimney as soon as the fireplace fire has gone out. A photo-Darlington transistor is used to sense light and radiated energy from the fireplace. When no longer present, a light will start to blink telling you to close the damper. Est. cost: $10.
RADIO-ELECTRONICS Sep 1978 (v.49#9) pg. 41

Build this light sensitive security alert. Nearby movement will cause diffused shadows which are picked up by a photodiode and trigger the alarm. Est. cost: $25.
RADIO-ELECTRONICS Apr 1979 (v.50#4) pg. 44
Correction RADIO-ELECTRONICS Jun 1979 (v.50#6) pg. 6

Sensing circuits. Three methods for sensing when a circuit is active. Looks at light, coil, and series dropping resistor sensing techniques.
RADIO-ELECTRONICS Mar 1984 (v.55#3) pg. 76

Light-sensitive timing circuit. Use a change in light levels to turn on a circuit. Then a timer will turn it off after a predetermined time lapse.
RADIO-ELECTRONICS Apr 1984 (v.55#4) pg. 39

Robotics. Simple solid-state vision systems. Part 1. Constructing a simple photocell-based vision sensor.
RADIO-ELECTRONICS Nov 1986 (v.57#11) pg. 74

Robotics. Simple solid-state vision systems. Part 2. Connecting a simple photocell-based vision sensor to a microcomputer.
RADIO-ELECTRONICS Dec 1986 (v.57#12) pg. 81

Photocell switch turns TV commercials off and on in response to a signal from a flashlight. Est. cost: $12.
RADIO-TV EXPERIMENTER #806 Oct-Nov 1966 (v.21#2) pg. 53

Chanticleer, the electronic rooster. Device senses the sunrise and sets off an audible alarm. A useful alarm clock for those people who want to get up at sunrise. Est. cost: $15.
RADIO-TV EXPERIMENTER Aug-Sep 1967 (v.23#1) pg. 47

Electronic alarm signals a change in light levels. Can be used to signal the coming of sunrise or the dimming of the light of a campfire, among other uses.
RADIO-TV EXPERIMENTER Apr-May 1969 (v.26#2) pg. 35

Flash switch. Turn television sound off and on by shining a flashlight on this light sensitive switch.
SCIENCE & ELECTRONICS [1] Aug-Sep 1970 (v.28#4) pg. 75

Build your own Cyclops, a light intensity monitor that can be used as an intrusion detector or as part of an electronic rifle range. Printed circuit board template included.
SCIENCE & MECHANICS Fall 1979 pg. 74

Ptyalin experiments show basic enzyme action. Includes a photoelectric device to measure activity of enzymes.
SCIENTIFIC AMERICAN Jan 1963 (v.208#1) pg. 147

Photoelectric temperature control device uses light bulb, thermometer and photocell.
SCIENTIFIC AMERICAN Oct 1965 (v.213#4) pg. 108

Build an electronic neuron. This hard-wired neural network tracks the sun by keeping two photosensors equally lit.
SCIENTIFIC AMERICAN Oct 1994 (v.271#4) pg. 136