Questions tagged [photosensor]

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2 answers
87 views

Understanding opamp amplifier (simple) behavior - Having trouble understand basic opamp operation

I'm trying to understand the operation of opamps, especially how to amplify a voltage as illustrated in the images from a (for example) photoelement so these can be used a the following comparator. ...
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1 vote
1 answer
219 views

Reading 100s photodetectors

I'm trying to measure light intensity at a lot of points in a project. I have about 250 photo detectors (BPX 65). When I had just 1, I tried connecting it to an Arduino board. But I'm not sure, what ...
6 votes
1 answer
841 views

Photodetector for short laser pulse

I'm looking at building a detection system for fast laser pulses (532nm wavelength for 250 ps duration). It seems to me that this will require a very fast photodiode with sub nano-secind rise time. ...
3 votes
2 answers
386 views

1940s phototube collector material / datasheet for a tube

I have browsed countless pages on Google but cannot find a datasheet that tells you the material/element of the collector plate (the semi-circular plate in the tube) in a phototube (not a ...
-1 votes
2 answers
94 views

Procedure to express radiantion intensity of a LED in watts/cm^2 , given luminous intensity or total radiant power [closed]

I am calculating Responsivity of a PN junction photodiode by irradiating radiation from LED sources. For this purpose, I have two LEDs, one UV and another green LED. Note that LEDs are placed close to ...
-4 votes
1 answer
62 views

In this circuit, the light intensity sensor (LDR) only senses 3_2 cm. How can I improve the sensitivity of this sensor to reach 1m?

In this circuit, the light intensity sensor (LDR) only senses 3_2 cm. How can I improve the sensitivity of this sensor to reach 1m? https://ibb.co/c3X1NRS
1 vote
2 answers
131 views

Extracting two signals from a photosensor

I have a circuit that pulses two LEDs on and off at the same frequency but out of phase. I would like to find a hardware solution for using one sensor to measure separately the intensity from each ...
0 votes
2 answers
155 views

Problem in sensor circuit using a Phototransistor for the Schmitt Trigger circuit

This is my Schmitt Trigger design, which trips at \$2.3V\$ and \$1.7V\$- Here, $$+V_{cc} = 9V$$ $$R1 = 51k \Omega$$ $$R2 = 22k \Omega$$ $$R3 = 330k \Omega$$ \$V_{in}\$ is a square-wave with 0-7V peak ...
0 votes
1 answer
74 views

Reverse photosensor is activating an LED but won’t activate a motor

I am trying to use a photosensor in reverse so that it activates when it is dark instead of light. I am using a 2N222 transistor. I tested with an LED and it works fine, but when I use the same ...
0 votes
1 answer
147 views

Connecting photoelectric sensor to Arduino for distance measurement

I've purchased some of these sensors"S15-PA-2-A00-NK" and I would like to use them as distance sensors to be read by an Arduino. I have no idea what type of signal the sensor even outputs or ...
0 votes
1 answer
55 views

Photogate is unresponsive - no output signal

I am trying to use this photogate with my Arduino Pro Mini (5V.) I am having no luck getting any readings from it. I measured the voltage across the emitter and got 4.5V, which should be enough to ...
1 vote
1 answer
95 views

I want to register a small change of voltage of a photo sensing diode at bullet's speed

What I intend to do Estimate Accuracy of a Bullet Hit from the Bull's Eye: Use a row of light sensing diodes like BPW34 (or you suggest) spanning a feet vertically and horizontally or so with laser ...
4 votes
2 answers
663 views

What is the "collector light current" of a phototransistor and how does it relate to the collector current?

I found the "collector light current" term in this datasheet (Vishay TEFT4300) but I can't find a definition for it on the internet nor figure out how it relates to the collector current. I ...
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0 votes
1 answer
163 views

HP C9017 Photosensor wire colors [closed]

I have at my disposal a photosensor (Optical encoder) with "C9017-80055", it has three cables: Black, Green, and yellow. I want to know the circuit (GND, VCC, output) to connect it with ...
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0 votes
1 answer
263 views

Trouble understanding OEM HP Sensor CB781-80006 circuit [closed]

I am having trouble understanding an OEM HP Sensor CB781-80006 circuit, I'm a beginner in electronics. Does anyone know to tell me what are the values ​​( VCC, GND, and outputs ) this sensor was ...
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0 votes
2 answers
44 views

I can’t remember the name of that component

I’m looking for the name of the component that act like a relay but instead of using a coil to generate a magnetic field that moves the relay « arm » it uses a LED and a photosensor. It allows to ...
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1 vote
0 answers
77 views

Current sensor that works in 0nA-250nA range?

Is there any current sensor capable of sense very low current ranges from 0nA to 250nA? I would need to sense the current produced by this photodiode: GVGR-S11SD (http://www.geni-uv.com/download/...
1 vote
2 answers
227 views

Need help with break beam sensors for an art installation

I've been commissioned to create a piece of public art that fuses technology, light, and sound. The final piece must have six beams that can be broken and trigger musical notes. My first idea was to ...
0 votes
1 answer
238 views

Photo eye sensor signal wiring

I am trying to install a photo eye to use for a lay down bottle sensor. I wired in the power, it turns on the light on the sensor flags when triggered. But I’m not abel to trace where the signal is ...
1 vote
1 answer
85 views

Existence of input signal to LED at photodiode output

I try to make simple LED/photodiode circuit by arduino and 741 op amp. I used mid-IR LED by 200mA current and suitable photodiode for it. I wanted make pulsed signal by digital output of Arduino UNO ...
1 vote
0 answers
57 views

Color Sensor Range

From what I've seen in spec sheets for modern color sensors (as of late 2020), the optimum sensing range is generally on the scale of centimeters. I am curious about the physics that can explain this ...
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0 votes
1 answer
116 views

HP C8941 Photosensor operating voltage and circuit

I have at my disposal a photosensor (Optical encoder) with "C8941-80018", it has three cables: Black, Green, and Blue. I want to know the Operating voltage for this optical encoder and a ...
0 votes
2 answers
70 views

Low precision flash detector

I'm interested in flash detection, what would be equivalent to 1000 FPS. High speed cameras that do this are too expensive and too heavy and provide too much information. In the long run I'm going to ...
2 votes
2 answers
190 views

Detecting small AC current signal generated by phototransistor

I'm trying to detect a small AC signal (~10kHz) generated by a phototransistor on a magnitude of 10nA~1uA using the following circuit by converting the signal to voltage signal first and then filter ...
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0 votes
1 answer
296 views

How to modify IR auto-close circuit for trash can lid

Just bought a new trash can with an automatic lid that I'm fairly happy with, but there's one modification I'd like to make. If I place the trash can in a cabinet and close the door it detects the ...
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2 votes
1 answer
120 views

Phototube experiment with op amp

I'm working on an experiment to find Planck's constant with a phototube. I built the following circuit and pointed an LED light to the phototube in a dark room, but I had a few problems: When there ...
3 votes
2 answers
716 views

Reflective optical sensor

I am working on a project that uses a TCRT5000 reflective optical sensor. Sensor datasheet is here I tested this sensor in a room, the voltage at the output pin is high it is above 2.5V. While ...
0 votes
1 answer
92 views

Photo-multiplier Tube Pin Configuration

Pin configuration of a photo-multiplier tube (PMT) is presented in its manual as can be seen in the attached image. All dynodes have been related to specified pins (numbered circles in the image) ...
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1 vote
1 answer
267 views

HP C8941 Photosensor wire colors

I removed a photosensor from an OLD hp Inkject Printer. The photosensor is called "C8941-80018". I can't find any datasheet online. Does anyone know what wire color is what?
2 votes
2 answers
140 views

What is the origin of multiplicative noise from a DSLR sensor?

I'm trying to understand the behavior of my DSLR camera sensor (Canon 80D). I've taken a picture of a gradient from top-right to bottom-left corners of a square. This square is positioned at the right-...
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1 vote
1 answer
341 views

Solar Panel-Photocell Wiring

I am trying to help my dad with a project of his where were trying to build a lighthouse powered by solar panel in which it spins a motor at night and charges battery during the day. This is a DC ...
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0 votes
2 answers
582 views

What options exist for a for low-latency (<1ms) photosensor?

I'm wanting to build a computer keyboard-to-display lag measuring tool using an Ardunio: User places the photosensor right-up to their computer monitor. User presses a button on the Ardunio. The ...
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0 votes
1 answer
74 views

Is the charge accumulation linear in time for image sensors?

Reformulating the question: Does the rate of charge of the pixels photodiodes in an image sensor depends of the previous accumulated charge? The pixel sensor integrates light during a specific ...
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0 votes
3 answers
129 views

Infrared Sensor for drug detection [closed]

I saw that there has been a push to make a drug detector that can identify cannabis since it has been legalized. I was looking at mouser.com and found this ir sensor: https://www.mouser.com/...
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0 votes
1 answer
73 views

Pachislo Token Sensor Optical sensor replacement part#?

Pachislo Token Sensor Optical sensor As shown above I have a Pachislo Mazya Dynamite Kid's Machine which has a bad Token Sensor Booard. Can someone please advise on what a suitable replacement part ...
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1 vote
1 answer
637 views

Convert a Dusk-to-dawn outlet device to Dawn-To-Dusk? [closed]

I recently purchased a Dusk-to-dawn outlet sensor (https://www.amazon.com/dp/B00002NB2X?ref_=pe_2640190_261118450_302_E_DDE_dt_1), but I'm wanting to convert this thing into a Dawn-to-Dusk device ...
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2 votes
2 answers
129 views

Can linearity of photoreceptor be improved by calibration?

I am trying to determine if equipment I already have can be used to take a reading in mcd/m2, for a quality control test. I have a sensor which meets all the requirements listed in the standard test ...
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0 votes
3 answers
1k views

identify infrared receiver

My CD player's infrared receiver for its remote control has failed. (The remote still works with a friend's identical player.) I'd like to buy a replacement receiver and solder it in. How do I ...
1 vote
2 answers
228 views

Driving Avalanche Photodiodes (PCBs)

I am using Avalanche Photodiodes and I was told that they use a much higher voltage then standard photodiodes and I was wondering if I need a High Voltage PCB to drive them? I am currently just using ...
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3 votes
5 answers
720 views

Please explain this formula for the relationship between bandwidth and the temporal response of a photodetector

I am reading "Optoelectronic Sensors" by Didier Decoster and Joseph Harari. At section 1.8.2 they start explaining the relationship between rise time and bandwidth, and they give a very weird formula ...
1 vote
1 answer
976 views

How to find polarity of photo interrupter

I have scavenged some photo interrupters from multiple printers but I am trying to figure out the polarity and the voltage. I've tried searching up photo interrupter polarity but couldn't find ...
user avatar
0 votes
1 answer
188 views

Dusk dawn motor driver with polarity reversal

I'm trying to accomplish this. When a dusk dawn switch is on, drive a small DC motor for a few seconds and then stop. when the dusk dawn switch is turned back off, then turn a small DC motor THE ...
0 votes
2 answers
842 views

Photodiode temperature compensation

The goal is to design a circuit that can accurately measure light intensity with little temperature dependency. Common application uses photodiodes to do so. Photodiodes can be measured either in ...
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1 vote
1 answer
264 views

Replacing obsolete photodarlington with phototransistor

I've got an old circuit design I need to replicate, function wise, to fit into an existing larger design. Logic I can usually handle, anything with transistors starts to get me lost. My strength is ...
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0 votes
2 answers
660 views

Photo-diode for a high-frequency tachometer

I intend to build a tachometer, which is capable of detecting rotations up to 1kHz (60 000 RPM). From the Internet I know that this is possible to do with a magnet and a Hall detector. However, I ...
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0 votes
1 answer
972 views

Design of output stage for CNY70 reflective sensor

I have built the following circuit for a reflective sensor: The resistor \$R_D\$ has been given the value 200 \$\Omega\$ and the resistor \$R_T\$ is to be dimensioned. \$V_{CC}\$ is 5 V. I have ...
-1 votes
1 answer
86 views

Why popular line detection use Infrared(IR) based sensor? [closed]

Popular line sensor use IR LED as transmitter and IR photodiode as receiver to distinguish reflective color such as white and less reflective color like black. Consider that infrared LED is hard to ...
-1 votes
1 answer
71 views

Why there is difference between image size and video resolution of a specific camera? [closed]

I was searching to buy a camera, but I saw in specs they wrote: 2MP(full hd) video recording 5MP image size Why the vido size is 2MP but image size is 5MP? How ...
1 vote
1 answer
7k views

How to increase sensitivity of Light Dependent Resistor (LDR) [closed]

I am using LDR sensor in my project. The source of light comes from the different colour of images. As we know, the spectrum of each colour is different and it will produce a different intensity of ...
1 vote
4 answers
1k views

Detecting a very fast moving object with a photoelectric sensor

I want to use a photoelectric sensor to detect a ball that is moving past the sensor at 85mph, which also equals 136kph or 3800cm/sec. The ball is 7cm in diameter. If my logic is correct that means ...