Questions tagged [optoelectronics]
Components, circuits, or systems that convert between electrical and optical (light) energy.
0
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24 views
Choosing a camera for near-infra-red illumination analysis
Which parameters are important to look for in camera specs./data-sheets if it will be used for irradiance pattern analysis from near infra-red sources. Typical spectra range of interest is from ~700nm ...
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0answers
17 views
Optocoupler or transistor.. which is good for high load relays using Arduino
I'm a newbie or a beginner with electronic stuffs. I'm trying to switch on/off a 1.5hp water pump using Arduino. I've got a 40 amps solid state relay in which the coil voltage is 12-36v. So for that I'...
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2answers
26 views
How will the resistance of this Evaluation Module affect the measurements of the current produced by this photodiode?
A little context: This is part of a bigger project about glowing algae, my job is to design a photodiode array to measure the amount of light the algae produce in response to movement.
I have a good ...
2
votes
2answers
65 views
Help understanding power ratings in optocoupler datasheet
I want to understand this the datasheet for the Everlight EL817 optocoupler but don't know what is the maximum power can the output hold.
I see an optocoupler as a kind of switch that closes a ...
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2answers
65 views
Better resolution with photodiode (LTR-536AD)
I want to build something like a fog-sensor.
I'm using a laser and on the other end (~20m) I have a LTR-536AD photodiode. I hooked the photodiode to an arduino and was monitoring the voltage.
My ...
0
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2answers
57 views
Measure laser with photoresistor (LDR)?
I want to make a simple setum, where I can measure the opacity of air. I want to use a simple laserbeam, which I shoot across the room, and on the other side I want to measure how much is blocked/...
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0answers
61 views
Ground Test with MID400 (Optoisolator)
I design my controller, one of the tasks of which is to check the operability of grounding in an AC line.
The controller will be built on the basis of ATMEGA328P (Arduino UNO), in the high-voltage ...
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1answer
54 views
How is optimum series resistor of an optocoupler sized?
I want to learn how to size the series resistor for this optocoupler which has a high CTR.
I will use Arduino's 5V digital output pins for eight of this coupler so I really want to source necessary ...
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2answers
56 views
Trouble changing an optocoupler without changing circuit functionality.
As a part of a circuit an optocoupler was driving the gate of a MOSFET as follows:
Now I need to change the above opto with a 4N46 darlington one.
I'm not familiar with these much and having ...
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1answer
47 views
What does “off-state output terminal voltage” in optocouplers mean?
I was looking at possible options of what optocouplers to use in my project. I was looking at these parts.
https://www.fairchildsemi.com/search/?searchText=MOC3023-M#N=&&Nao=0&&Ntk=...
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2answers
68 views
optical path resonance distance measurement device, super useful for open source hardware if it would work [closed]
My head just tends to be full of open hardware and open manufacturing stuff, and one idea I have had for years and always wanted to try, but never could for want of access to an electronics lab, is a ...
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1answer
124 views
LOGIC GATES and logic circuits in a calculator
i am tasked to do a circuit using logic gates regarding the work of a calculator. it is said that how can we make number 3 shown in a calculator represented by logic gates. can someone help me?
i ...
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2answers
77 views
Identifying mystery dual channel opto detector?
How do I identify if a component is a photo diode or photo transistor? I have a three lead component removed from an old mouse where it was used to do quadrature encoding of the scroll wheel (a normal ...
0
votes
1answer
54 views
MID400 used in “Unsaturated” Mode
I've been spec'd a MID400 in a high voltage A/C power monitor circuit. After receiving the prototype (board is done), I've determined this device is for power on/off application. Problem is I need to ...
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1answer
109 views
What is comparison of readout times of global and rolling shutter cameras? [closed]
Rolling shutter will take more time because of sequential readout and global will take less time.But what are the exact values of image readout time?
2
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4answers
893 views
Why we use two photodiodes as optoisolator or optocoupler?
Why do we need two photodiodes in order to create an optoisolator or optocoupler? Many sources say that it is to compensate for the non-linearity of the diodes, but is there any explanation based on ...
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0answers
42 views
How to read spectral responsivity curve?
I'm currently trying to work with TCS3200 color sensor, I came across a spectral responsivity curve in the datasheet.
Suppose, if I place a color with RGB value 255,0,0 that will be around 640-670nm. ...
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2answers
234 views
24 VAC Detection Using Optocoupler
I have been using an HCPL3700 to detect 24VAC, but they are large and relatively expensive. I have tested the design shown in the figure (AC input to the diode, and measuring output collector-emitter ...
0
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1answer
140 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 ...
2
votes
1answer
112 views
Questions about CNY70 Reflective Optical Sensor datasheet
I am using the CNY70 for a project, but i need information from the datasheet. In Figure 11, which i have added below, the relative collector current, \$I_{Crel}\$, is shown versus the displacement, s,...
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votes
2answers
100 views
Automatic room light controller with IR sensor
(Schematic source: Electronics Hub)
In this circuit sensor is not working.using (4*1.5)v cells as supply.without connecting the transmitter and receiver elements,in the o/p led glows.i have connected ...
2
votes
1answer
247 views
SWD optoisolation problem
I have designed the following optoisolator for SWD interfacing with an STM32 device and J-LINK programmer:
This is the generic schematic:
And this is a single optoisolator schematic:
I am not able ...
5
votes
2answers
515 views
Typical wavelength range for solar cell measurement
Why is a wavelength range of 300nm-1100nm usually used to investigate the properties of solar cells (EQE, current generated, etc.)? Is it to reduce spectral impact? I also don't understand what is ...
0
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1answer
77 views
Detect if the load is present on this circuit
Is there a way to detect if the load is conected on the circuit above?
(The other load should be connected to the F Pad, sorry for the mistake).
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0answers
89 views
Low cost low speed fiber optic connection for embedded applications
I would like to use a fiber connection to send data between two nodes. The nodes would typically have a 8 or 32 bit micro controller. I need data rate of 2 Mbps or higher and distance is about 100 ...
5
votes
1answer
371 views
Q: Check if an LED in my circuit is still “good”
I have an electrical circuit which uses an LED, connected to a µC, to show the status of an x-ray source in another room. Obviously this LED is important to have in a working condition.
Now, LEDs can ...
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0answers
61 views
Material choice / optical properties for solar panel cover (glass/perspex/lexan)
First off I realise this is sort-of off-topic but this was the most relevant stack site I could think of...
I have a Bosch solar panel which was damaged by couriers, the glass covering was shattered ...
0
votes
1answer
230 views
4n25/35 optocoupler detect led on/off
Hey all i am just wondering if my drawing below is correct in order to have an arduino detect an on or off led on another board using a optocoupler?
My thoughts of the above drawing is that when the ...
0
votes
2answers
800 views
LED response time (time to warm up)
Can someone help me to explain why LED have better response time when compare with other light source (ex:fluorescent lightbulb). Because their structure or anything else? Thanks everyone so much.
1
vote
1answer
140 views
How Gigabit Ethernet is achieved in fiber optics?
I understand how 1000BaseT works on Cat 5 cables: It uses clock rate at 125 MHz, 4D-PAM5 data encoding to transmit 2 bit per cycle and it uses the four pairs of the cable. The math is quite simple: ...
0
votes
3answers
164 views
Why is this circuit isolated?
From Linear Optical Isolation for Safe Sensor Operation:
Are the three grounds indicated all connected?
Are the four Vcc indicated all connected?
If the above is all true, how could this be an ...
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2answers
462 views
Minimal component set to build a computer mouse [closed]
I am searching for a DIY set to build an optical mouse.
What I need is a bare minimum set, giving the ability to build
a very small mouse without buttons, and possibly for beginners.
Should be ...
0
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1answer
262 views
Isolating Digital IO from Microcontroller
I have designed an Embedded System in which the PCB has both Non-Isolated and Isolated DC DC converter.
I am taking a 24V DC Supply from a PLC Device. Converting it to 3.3V with a Non -Isolated DC DC ...
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0answers
47 views
Check if signal drifts are temperature related
Let’s say I have an output signal vs time plot data of some opto-electrical device (a black box for me). If the device is exposed to sunlight the signal starts to drift to higher values.
Is there a ...
0
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1answer
471 views
Solid angle measurement conditions for radiant intensity specification in IR-LED's data-sheets
For some IR-LED's their data-sheets state Radiant Intensity and the conditions under which
that number was obtained, indicating also which solid angle was used for the measurement.
For example, this ...
0
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1answer
67 views
How to connect chip pin to either vcc or groud externally?
I have a board that i use ic which one pin need to be externally decided to be connected to VCC or ground based on LED lightening
The schematic use this symbol for a connector to indicate this
How ...
0
votes
1answer
144 views
Test an LCD for missing segments without looking at the screen? [closed]
I have a product with an LCD screen that sometimes fails with missing segments.
I will test the product for a long time to replicate the failure.
I will test many at once.
I don't want to sit watching ...
0
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2answers
223 views
What can I use instead of a CD4007 transistor? [closed]
What can I use instead of a CD4007 transistor, or how can I simply design a "20 watt or larger" speaker using a "TBA810" or any available widely available and used IC?
I found this circuit: Touch ...
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0answers
417 views
Detecting AC 220v signal
I am building a device that senses when the ac is on and is between 160v and 280v. The electricity in Iraq is crazy sometimes so when there is powercuts the ac will still be live at 30-50v. I will be ...
2
votes
3answers
577 views
pc817 large emiter collector voltage drop in saturation
I'm experimenting with a very simple circuit with a PC817 optocoupler. I just want to turn on an LED with the optocoupler output, but the bright is really low in comparison to a direct drive of the ...
1
vote
2answers
105 views
Lowest noise, low frequency, cheap photodetector configuration? [closed]
Currently we are measuring the position of a mechanical beam by illuminating it with light from an IR diode and using two phototransistors to measure the difference between light passing over and ...
0
votes
1answer
851 views
How is the H11AA1 ic working with AC mains voltage?
I am making an arduino controlled fan speed controller that would digitally control the speed of my ceiling fan working on 230 VAC and 50 Hz. I am using the following circuit which is designed for ...
2
votes
3answers
3k views
Why is it “Vactrols” are not commonly used?
I've been trying to get my hands on some Vactrols (opto-variable resistor) for a long time, unsuccesfull. Not even digikey has them.
some examples: VTL5C2,VTL5C3,NSL32
Can't see them as "too ...
0
votes
1answer
352 views
How to connect 111ager Solid State Relay with Arduino to control a 5VDC@2.1A load
I just bought from ebay 111ager SSR 3-32VDC input power supply with load current upto 5A @ 5-220VDC. Link to the product: (https://goo.gl/MOkAU3).
I wanted to use it to control a 5VDC@2.1A load using ...
23
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3answers
5k views
How does a 40 Gbit/s Ethernet interface process packets in silicon?
A 40 Gbit/s Ethernet interface should have a 40 GHz signal on it. How does common silicon IC technology handle such an exotic beast?
My best guess is that internally various parallel busses are used, ...
1
vote
1answer
80 views
Designing a dental furnace control board
I have a few question about designing a heater control board . Firstly I took a power electronics lecture in the university eon ago but now I try to remember it anew. :)) Regarding my subject, I have ...
0
votes
1answer
377 views
Opto coupler keeps on breaking
Good day,
I am building an H-bridge (picture below). My opto couplers were ILQ74. I am using 560 ohm current limiting resitors for the opto coupler diodes, with an input voltage of 3.3V (from MCU). ...
3
votes
3answers
876 views
IR receiver output pulsating instead of constant one('5V') or zero ('0V')
I am trying to detect the size of different bottles on a conveyor belt and for that I thought of using IR transmitter and receiver but I am not getting desired output. I want the output of IR receiver ...
1
vote
3answers
1k views
Digital Optical Volume Control with LED and photoresistor (light to seperate circuits, optical pot)
Story
At first, I know the existence of a digital pot. 'Problem' is you need an IC to achieve this and also want to keep the circuits completly separated (and simple). Also want to use it with an ...
0
votes
3answers
244 views
Relation between collector current and IF current in an optocoupler?
I need to use an optocoupler to drive BJT. BJT will let 10 A current pass. BJT's have commonly 100 - 150 Bf(current gain) so for 10A transmission I need at least 100 mA current draw from the ...
