Questions tagged [optoelectronics]

Components, circuits, or systems that convert between electrical and optical (light) energy.

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2k views

Opto-coupler base connection speed influence

I am using a 4N25 opto-coupler for 5kHz to 10kHz application. In some datasheets the turn on and turn off times are mentioned to be 3us. I am wondering if this opto-coupler is suitable for my circuit'...
2
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1answer
737 views

Why do fiber-optic interfaces have much higher bandwidth than optocouplers?

I've noticed that optocouplers typically have a bandwidth in the kHz range (i.e 200 kHz). Fiber-optic interfaces can reach speeds of 100 gigabits / sec. What's so different about these two ...
1
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1answer
376 views

LPI requirement on optical encoder

I am using the AEDR-8300 as a simple optical encoder solution. The part seems simple enough: An LED emitter Photodiodes that pick up the light that is reflected from a codewheel or black/white strip ...
2
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2answers
691 views

isolated input circuit to check regular switch or photo-transistor

I am trying to develop a circuit that is compatible with a regular switch (push, reed, other) and also a phototransistor. The application is pinball, where there are any number of switches and IR ...
0
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2answers
177 views

Led's in series light power degradation with strange results

I am doing life cycle test for 7 led's connected in series with current limiting resistor.(picture for reference) I am measuring light power(mW) with Thorlabs photo resistor for each led. Led's ...
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2answers
214 views

How to use Max3795 for driving VCSEL at 100 MHz?

i am trying to drive my OPV380 see datasheet( http://optekinc.com/datasheets/OPV380.pdf) with a square wave data at 100 MHz. i am using now a Max3795 (http://datasheets.maximintegrated.com/en/ds/...
2
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4answers
1k views

Operating a 0.08 amp fan using capacitor

I am developing a hot air blower made out of 40w heater, 25mm fan and 12v power supply. I want to be able to keep the fan working in case that the power supply is cut off, so in case the heater is ...
0
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1answer
2k views

high speed optocoupler circuit

I have 4n35 optocouplers, I am using these to isolate a motor driver circuit and the Arduino controlling it. I put one on the slave select pin and one on the tx line to the motor controller (there is ...
0
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1answer
2k views

Application of AC optocoupler [closed]

I found this circuit for an AC optocoupler: For this circuit, what would be the criteria to choose the correct resistors and capacitors? Why were these values chosen? How do I select the right ...
0
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1answer
404 views

Normally closed SSR won't work with grounding out a magneto's primary to ground

I've been trying to find a device that will ground out a magneto's coil (primary kill wire) in a normally closed state without using a mechanical relay because I want my circuit to be all solid state. ...
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0answers
467 views

Designing circuit with Arduino and optocoupler: beginners problem

Firstly, I am a beginning hobbyist starting doing some electronics and this is my absolutely first attempt in trying to automate something. Here is my circuit (or what I intend): I don't know if my ...
1
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1answer
284 views

How do I reverse this following circuit, i.e. when the laser is off then it should stop buzzing?

All the necessary symbols are given in the circuit itself. When the laser is shooted to photoresistor, then buzzer stops. I want to stop the buzzer as soon as laser gets off.
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1answer
185 views

How to create a photogate that can span tens of feet with multiple sensors to capture items of various sizes passing through it?

I'd like to create a photogate can create a plane of detection approximately 3' tall by 8-10' wide, with the ability to detect items as small as 6" tall pass through it. I am envisioning two ...
2
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1answer
1k views

How can I detect when an LED changes color from red to green and quickly send a message to a PC to capture an image from a camera?

I am working with a 3rd party IR curtain system, and the only way to tell in real-time that something has pierced the curtain is an LED at the top of the sensor pole that changes from green to red ...
0
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2answers
84 views

What transistor to use in place of QVE11223 opto

In the circuit below, I'm trying to replace the physical switch on the 'flipper opto switch board' (and 'power driver board') with a transistor, controlled by Arduino. My understanding (please ...
2
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1answer
300 views

IR receiver part interchange

I've got an old stereo that doesn't have a remote control. There was a model that did, and after looking at the service manual it looks like I just need to populate a PCB with an IR receiver to add ...
0
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1answer
712 views

JESD204 ADC - fiber optic?

There's a Youtube video of a high speed ADC, using JESD204 high speed interface, interfacing with an FPGA via a fiber-optic transceiver: http://youtu.be/vkrms2udeKI Is there a commercial version of ...
0
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1answer
74 views

Running electro-optic modulators in reverse

An lithium niobate electro-optic modulator allows one to modulate the amplitude (or phase) of an optical signal by applying a bias. But what voltage would I measure across the bias input if I applied ...
1
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1answer
1k views

How to model transistor ATF 53189 in QUCS?

In my internship I have to create an amplifier with low noise, high impedance and that works in the 100 to 400MHz band. While searching for a transistor, I found the ATF 53189 (datasheet), which ...
3
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2answers
17k views

How to calculate exactly resistors values of opto coupler

Optocupler: FAIRCHILD MOCD207M According to the data sheet with If=1mA minimum CTR is 34%. Using series resistor of 1.5k at 3.3V gives If= (3.3-1.2) / 1.5k = 1.4mA. The collector is connected ...
0
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1answer
637 views

NPN optocoupler

I have made a circuit but I fail to interface optocoupler with preamplifier can any one help to troubleshoot,when I disconnect preamplifier the output from the AC Voltmeter is 0.5 Volts but when I ...
5
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2answers
488 views

How to detect glue without surface contact

I am currently working on a project that requires a section of "release liner" to be removed and a clear plastic to be put in its place after a few holes are punched out of the paper. What I am trying ...
0
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1answer
704 views

How to digitally “amplitude modulate” an LED

I am wanting to do some open-air LED communication experiments. I have a receiver that detects Amplitude Modulated light signals, and then converts that into sound. Currently, I hook up a series ...
1
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1answer
911 views

how to make a system respond to IR laser? [closed]

Lets say i have 2 separate systems called Box A and Box B. Box A has an IR laser beam attached to it. What equipment can i use to make Box A make a certain action ONLY when the IR laser attached to ...
4
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1answer
98 views

Ruggedizing a component for extended temperature

I am doing a system design presently which involves an OEM optical amplifier module (Dimensions: 220 x 250 x 60mm). It has got an operating temperature range from 0 deg. to 40 deg.C. However, my ...
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2answers
1k views

How to wire up optocoupler for digitally controlled UV (under voltage) input protection?

What I am trying to build is an under voltage input protection. It will always limit the voltage flowing into the output end to the microcontroller to be 3.3V, but when the input goes below 380V, it ...
3
votes
1answer
729 views

type of capacitor (0.01uf) for this circuit?

I'm having difficulty sourcing the correct/safe capacitor for this circuit (despite my research). I know it should be 0.01uf and is being used in a 120v AC (upto 10amp) circuit. Schematic below. Also ...
3
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3answers
3k views

How to display images in ultraviolet?

The purpose of this is to show images to mice, which have one UV shifted cone relative to humans. An ideal solution would be a monitor that had 3 wavelengths : 365nm, 410nm, and 500nm. But, the 410nm ...
2
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2answers
450 views

Audio optical cable electronic switch

Right now I'm using this to switch between three devices for my home stereo and I want to replace this with an electronic method (no moving parts) with a remote I made. I already have an rf module ...
3
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2answers
3k views

230V AC / 460V DC Optocoupler using Led and Voltage Divider

I am building a primitive optocoupler to sense if a bulb has blown/if current is flowing. It receives either 230VAC or 230VDC (rectified..) as supply. I have calculated and built a voltage divider as ...
5
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5answers
14k views

Using an Opto-Isolator to detect 120VAC on a Microcontroller

I am designing a system where I need to know whether or not 120VAC is present on a specific wire. The system is in line with a fuel pump system, and I need to check to see whether or not the pump is ...
3
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2answers
4k views

Point-to-point range measurement using an IR receiver

I am interested in using an IR receiver (as opposed to a standalone PIN photodiode or phototransistor) to measure distance/range. I thought I had found an appropriate match in Vishay's TSSP4P38 mid-...
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1answer
1k views

Wrist-based Pulse Oximeter

I'm quite new to EE. I'm trying to design a wrist-based Pulse Oximeter. I have looked through a lot of literature and short listed these: PhD thesis using 6 LEDs A Single-Chip Pulsoximeter Design ...
0
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1answer
3k views

How to implement a delay OPTOcoupler input there by the circuit remain on for the next 1 second

I have another new project, the project is simple one when a call lands to the mobile an ac machine is triggered and it turns off when the mobile ring stop, for that I have used this circuit The ...
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2answers
1k views

Heart Rate Circuit

I am building a heart rate circuit followed the instructions in this site: http://embedded-lab.com/blog/?p=5508 Basically, the circuit works when we place the photo detector and emitter on the ...
1
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1answer
242 views

How do I find a commercial LED with 1625nm wavelength?

I'm looking for a LED with an emission wavelength of 1625nm for a project, but have been unsuccessful thus far in my search. How would I go about finding a commercially available LED in this range? Is ...
1
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2answers
212 views

Optical sensor for picking up 15 mm² area at a distance of 1 cm and return RGB value (or similar estimate)

I need an optical sensor for picking up 15mm² area at a distance of 1 cm and return the RGB value or any similar estimate. I am going to use a custom lens for this focus. This is basically to read ...
3
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3answers
601 views

Microcontroller or arduino alternative for small cell-phone sized device?

I am doing a project in which I need to read RGB values from a color sensor TCS230 and send it to a microcontroller and use an linear equation to get glucose value from it and display it on an LCD.As ...
3
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2answers
5k views

Stepper motor phase

I have a question related to stepper motors. What does the "phase" of a stepper motor mean? I mean when we say that a stepper motor is a 2 phase stepper motor or a 4 phase stepper motor, what does it ...
8
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2answers
13k views

Measure power supply ripple with Rigol DS1052E

I recently received (as a birthday gift) a Rigol DS1052E oscilloscope. I read about oscilloscopes but I never really used one. So my question is: How can I measure the ripple voltage of a floating ...
1
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1answer
127 views

Electrophoretic Displays

I am extremely interested in learning about electrophoretic displays. On their architecture, how they function and also would like to assemble one from the scratch for myself and see how it works (I ...
4
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3answers
3k views

Electro Optics vs Optoelectronics > What's the difference?

I've seen both wikipedias of Electro Optics & Optoelectronics but I'm still confused on what the difference is. I'm currently pursuing a degree in either Physics or Electrical Engineering because ...
2
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1answer
573 views

Water Meter Monitoring

Working on a project where I am wanting to monitor water meter via a magnetic sensor which will detect the spinning magnetic disc. It's very similar to the project this person has accomplished: http:...
0
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2answers
408 views

Creating an electronic switch for controlling a headset's control button

Some background information I have an Android based phone. The headset that came with it uses a TRRS connector. We normally have a button on the headset which when pressed, would allow you to play/...
2
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1answer
257 views

Scattering matrix Transmission Matrix lasers

I would like to ask if anyone can suggest me a good tutorial about Scattering and transmission matrices for lasers. I am really struggling with some issues and the majority of the literature analyses ...
0
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1answer
886 views

Laser Turn-on delay

When switching a laser diode, the turn on delay depends strongly on the initial bias current in the off state. This affects the duty cycle when attempting to generate a square wave. It also can ...
1
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2answers
7k views

Current modulator for laser driver?

For a project, I like to feed a sine wave to laser, this sine wave must have a DC value of 2V and it should oscillate between 2.5 and 1.5V at 100KHz. The current required is <50mA. What is the ...
8
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3answers
10k views

Using a LED to transmit data

I am curious about the possibilities offered by LEDs to transmit data over a short range (2 or 3 meters), and what maximum data transmission rate can be expected from carefully chosen, but consumer-...
1
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2answers
624 views

Cheapest way to do an IR re-transmitter (IR protocol agnostic, dumb device is good enough)

Looking out for ways to retransmit IR, bi-directionally, like this: ...
0
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1answer
425 views

Which device amplifies the optical signal in fiber optics?

My teacher ask me one question. How the optical signal or information was transfered in fiber optics communication? Then i explained it and use the word optical amplifier then teacher ask me what is ...