Questions tagged [optoelectronics]
Components, circuits, or systems that convert between electrical and optical (light) energy.
201
questions
0
votes
1answer
50 views
Can I use 1 optocoupler to drive 4 MOSFETs?
I've this circuit and works correctly, now I need to control 4 MOSFET instead of 2, is the second schematic correctly?
-1
votes
0answers
42 views
How to check input and output of this circuit?
I needed to test the OPT 202 ( it is basically a photodiode with on chip amplifier). From datasheet I understood that the output is proportional to input current based on wavelength. I have given ...
0
votes
1answer
31 views
Adjusting Voltage regulator with PWMed optocoupler
I have LD1084V adjustable voltage regulator powering servo and want to control its output from MCU. Optocoupler should behave as variable resistor so my thinking was :
I am mainly concerned with gray ...
0
votes
1answer
62 views
Opto-isolator/ optocoupler for electric isolation in IC design
I came across while reading the opto-isolator technique used for electric isolation in embedded systems/ Integrated Circuits design that " Opto-isolator is not recommended for electric isolation ...
0
votes
1answer
45 views
Help using an FOD3182 OptoCoupler
So this is the Optocoupler I will be using:
https://html.alldatasheet.com/html-pdf/505064/FAIRCHILD/FOD3182/978/2/FOD3182.html
My question is with the schematic of the data-sheet. Using Ni-multisim I ...
1
vote
1answer
139 views
How can I test a TLP582 optocoupler?
Have few of these components (TLP582) and I need to design a test circuit to test its functionality.
Datasheet of TLP582
I have no idea how to make a circuit for this.
What should I be testing in an ...
2
votes
1answer
43 views
Driving a 14-pin with DFB laser using D2570H
For our project, we would like to use the D2570 DFB laser from Agere system since it has a built-in photodiode with a TEC sensor, thermistor and a bias-tee embedded in an 'all-in-one' package.
However,...
1
vote
1answer
75 views
Circuit to replace a relay
I want to make a simple ladder circuit to control the on and off of a light bulb using 2 switches, but I am going to manipulate one of the switches by means of a microcontroller, and also I don't want ...
0
votes
1answer
45 views
Understanding peak repetitive surge current
I have moc3021 optocouplers. The data sheet says it has a peak repetitive surge current rating of 1 amp, 120 pps. I was hoping to use a microcontroller to control 24V .800A AC with this optocoupler. ...
0
votes
2answers
50 views
Best way to AND all connected inputs to one output
I have an CNC router with 7 x SN04-NPN sensors connected in parallel with one control board input. The problem is obvious, i got random false endstop triggers due leaking of SN04. I know i should have ...
3
votes
3answers
1k views
Position of current limiting resistor
I am designing a digital output circuit.
I got confused about the position of the current limiting resistor of the transistor.
I would like know where it should be. (After or before the pull up ...
2
votes
1answer
39 views
How to compare OLED and LCD brightness
I am trying to build a night clock projector, inspired by this project: https://microengineer.eu/2018/05/01/diy-night-clock-projector/
As I am more a computer scientist than an electrical engineer, I ...
5
votes
0answers
49 views
Ham Transceiver to computer Interface design question
I am building a Ham transceiver to computer interface, which has the RS232 port controlling the PTT on the radio. The circuit currently calls out for a 1.2K resistor in series with the RTS line and ...
0
votes
1answer
78 views
Photon lifetime in an optical cavity
Hi I have the following problem and data for an optical cavity.
Length \$ L=100 \mu m\$
Reflectivity \$R=0.33\$
Refraction index \$n=3.6\$
Inner losses \$p_i=20 cm^{-1}\$
Now I have to determine the ...
0
votes
0answers
21 views
Getting the optical power of a UV-LED using a spectrometer data
if it is possible can you let me know the way to get the radiated power of a UV-LED using the output data from the "Ocean optics- Maya pro 2000" spectrometer, or the calculations needed to ...
1
vote
2answers
47 views
what is the reason behind DC level shift of the optoisolator ouput(collector of photo transistor) terminal?
i am using SFH-610A optoisolator to switch 1KHZ PWM signal. on input side of opto i am triggering from micro controller with series resistor 500 ohms. and on the output side i have pull-up of 3.3V ...
0
votes
1answer
49 views
Resistor between vcc and control signal in a rpi controlled relay board
I have been researching to design a rpi controlled relay board and I found these two schematics from two companies. Personally I trust the company in the image above but I am confused about R3 (10k) ...
1
vote
1answer
66 views
How to share a digital signal between circuits?
Please see this :
The Task
I'm trying to create a single module which can safely share a single digital signal.
The idea is that each (identical) module can monitor the status of the signal, and can ...
2
votes
1answer
66 views
Please help me understand how this inductive proximity sensor works
I'm trying to build out an optocoupler circuit to connect a new proximity sensor to my 3D printer and want to understand how it behaves before implementing.
It's a Printrbot Simple Metal, Printrboard ...
0
votes
3answers
136 views
A laser driver (MLD203P1) with an external Bias-Tee for modulation
As the title says, I would like to add an external Bias tee to modulate a high frequency signal into a laser diode, because the laser driver I have chosen does not have a built-in modulation circuit. ...
1
vote
1answer
80 views
Opto-isolation amplifier output is too off
(As a follow-up to an earlier question answered by the community - thanks!) So I've got the test circuit setup using the HCPL 7520 (datasheet) now and planning to use an Arduino Uno to measure the ...
1
vote
3answers
59 views
Opto-isolation amplifier giving no output
First of all, thanks to the community for having such helpful answers here - don't post very often but here's one I could really do some help with.
I want to measure a voltage range of 0-100V DC in an ...
0
votes
0answers
21 views
What's the reason for keeping a base line in optocoupler? [duplicate]
Image Source: https://www.vishay.com/docs/83725/4n25.pdf
The pin no 6 of the optocoupler IC is connected to the base of the NPN transistor. Should I keep it open? Or grounded? Does it anything to do ...
0
votes
4answers
143 views
Laser scanning: Why are things like deflection and mirrors used instead of just a mount and servo?
In the Wikipedia article for laser scanning, it is said that laser scanning is the controlled deflection of laser beams, visible or invisible. It then lists some of the technologies used, such as ...
0
votes
1answer
54 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) ...
1
vote
2answers
36 views
Biasing network for phototubes and photomultipliers
I have some doubts about typical biasing network for vacuum phototubes and photomultipliers.
Precisely, let's start by a simple photocathode.
I have seen some biasing network like this one:
In this ...
4
votes
1answer
76 views
Charge transfer in CCD
I have a basic doubt about charge transfer between pixels of a CCD. Let's consider this animation (picture taken from wikipedia):
A precise time sequence of applied voltages between gates and bulk ...
0
votes
2answers
188 views
Photodiode Equivalent Circuit
I have some problems on understanding this equivalent circuit for a photodiode (picture taken from this article):
The author states that:
The equivalent circuit for a photodiode is shown in Fig. 1, ...
2
votes
3answers
1k views
Choosing series resistor for Optocoupler LED
How do you choose the series resistor value for the LED side of an optocoupler. My application uses this opto to interface a button that is about 25meters(50 meter wire roundtrip) away from the device....
0
votes
0answers
55 views
Why are thin-film surface-mount resistors particularly suitable for use in cryogenic environments/conditions?
I am currently studying The Art of Electronics, third edition, by Horowitz and Hill. Appendix C.4 Resistor types says the following:
The usual choices for general-purpose use are metal-film (axial-...
0
votes
1answer
130 views
Is it possible to model a PIN InGasAS photodiode in a SPICE simulator?
I want to know if it is possible to model a InGasAs panchromatic PIN photodiode, in accord with datasheet, in simulator SPICE MicroCAP 12. Because the supplier doesn't provide a SPICE model. And if it ...
1
vote
1answer
71 views
DC Solid State Relay Common Ground
I have an application which would involve having data lines connected to a microcontroller which would signal at lvttl (3.3v) levels and also take in 24v for a resistive load (~600mA). I have ...
0
votes
1answer
36 views
Raspberry pi to sense voltages 12 to 24, what buffer is good?
Hello I’m looking to use my raspberry pi in an automotive application where it will be used to detect when the vehicles ignition is activated and de activated. I would like the system to be 24 volt ...
0
votes
0answers
56 views
Photodiode, analog electronic
I am a beginner PSPICE, in simulation electrical and electronics circuits. I want to simulate a schematic with the program Micro-CAP 12. I want to look for some graphics from a photodiode PIN which ...
1
vote
2answers
103 views
Optocoupler Reference
I want to use in my project an isolated optocoupler like this one to switch an IGBT.
In the following schematic, taken from this Vishay application note there's a "floating supply" in Vcc1 as you can ...
0
votes
3answers
109 views
Are optocouplers enough of a protection to sensitive electronics
There are certain lines in my car which I want to detect when hot. My initial thought was to hook a voltage divider to drop from 12v (or ~14 rather) to 3.3 and feed it to my pi but I soon realized ...
0
votes
3answers
179 views
Ultra-narrow beam spread LASER diode
I want to build an optical position tracking system based on PSDs (Position-sensitive detectors). I searched online and found this PSD which has a sensitive area of 12 mm*12 mm. My goal is to allow a ...
2
votes
1answer
137 views
What is this black, marking-less, 6-pin surface mount device?
Below you can see the device I'm trying to identify:
It is mounted underneath the expression pedal in one of these:
Basically, below the pedal there is a little plunger which gets closer or farther ...
0
votes
1answer
107 views
Can I drive an optocoupler input with just 0.5mA (500 microA)?
Im trying to interface a keypad button in a device with a MCU, and they need to be in different circuits, with no shared GND.
This keypad button has 5V DC when not pressed, and 0V when pressed. I ...
0
votes
1answer
47 views
IR diode radiation spot area
How large is an IR diode radiation spot area?
I put some IR diodes (receiver and transmitter) in front of each other. I want each transmitter IR diode to only radiate on its reciever and not effect ...
0
votes
1answer
48 views
Gate-Souce resistors needed?
I completed an IR emitter circuit with two selectable power settings. It's working on the breadboard and I'm asking if I need the gate-source resistors for stability? As the circuit is battery powered ...
0
votes
1answer
67 views
Electroluminescent wire and EMC
I have been thinking about using EL wire in our house as a night light but I am concerned about electromagnetic compatibility and possible adverse effects on the inhabitants (we).
You can see these ...
0
votes
1answer
62 views
Photodiode not working in reverse bias
I'm using a photodiode module, model: coaxial InGaAs, Gtel.
I set it in reverse bias with 5V and tested it with a laser but it doesn't give any output voltage. Unfortunately I don't know the laser ...
0
votes
1answer
414 views
Optocoupler/isolater circuit for 24VDC sense that transfers switch status to 3.3VDC microcontroller
hope everyone is having a good couple weeks before Christmas, I was given this question for an assignment
How would you use an opto-isolator to sense a switch status in a 24VDC machine control ...
0
votes
1answer
348 views
Is this optocoupler driving relay circuit reliable and works great?
This is the circuit that I have, the optocoupler is an EL817 and the transistor is a BC817, the 24V relay is an Omron g2r_1_e, a 24V coil relay.
But when the optocoupler input is floating (not ...
0
votes
1answer
64 views
How do I model the optical coupling between two optoelectronic devices?
I'm building a circuit composed by two parts that are electrically isolating. One part has a LED (model: SIR333) and a phototransistor (model: SFH309FA). I basically have to model the optical coupling ...
0
votes
2answers
104 views
Simple switch with TLP222A
Electronic newbie here.
I'm trying to use a TLP222A as a remote switch for a small signal (3V and about 150-200mA at most).
It's super simple, but I can't understand why the following happens:
I'm ...
0
votes
2answers
96 views
Are mechanical relay signal pins isolated from the output?
I am going to use a magnetic mechanical relay to switch 240v AC.
I am using MPC250D6Z05APT, in its specification it did not say that the 5V signal is isolated from its output upon failure of the ...
0
votes
1answer
58 views
Optocoupler min collector-emitter voltage
I'm looking for an optocoupler but looks like I don't undersant their parameters well. What is "Optocoupler min collector-emitter voltage"?
For example, I found optocouplers like this but in the ...
0
votes
1answer
62 views
How does one match irradiance to Luminous Intensity in Candela of source?
A light source has an Irradiance of about 1.6 W/m²/nm at wavelenght 385nm and an LED:
Peak Wavelength 385nm
Viewing Angle 30 °
Luminous Intensity 80 mcd
If this light source shines on a ...
