Questions tagged [optoelectronics]

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

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39
votes
6answers
55k views

How do I model an LED with SPICE?

What diode modifiers are used in practice to model LEDs with SPICE (Berkeley v.3f5)? These are available to me: ...
1
vote
1answer
146 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
2answers
415 views

Detecting state of LED to control another circuit

I need to add functions to equipment I am not allowed to modify in any way. To do this I need to monitor the status of a Yellow/Amber LED and translate its status into a signal that can be used to ...
0
votes
1answer
169 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 ...
8
votes
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
vote
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 ...
1
vote
3answers
3k 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 ...
5
votes
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 ...
1
vote
3answers
207 views

LED Matrix Leakage LEDs

I'm doing a LED matrix design and it's a cathode row design. Attached is a picture of my matrix design. The design works ok and I can show any pattern in the matrix. The problem is when a leak LED ...
3
votes
3answers
149 views

Is it possible to use an optointerrupter as a optoisolator?

I currently can't buy an optoisolator, so I was wondering if I could wrap a optointerrupter in tape to shield it from light and use that as an optoisolator. Is this possible?
3
votes
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 ...
1
vote
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 ...
1
vote
1answer
394 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=...
0
votes
2answers
3k views

Opto-coupled PWM output

I have a circuit with two different ground levels. Using a optocoupler, I want to translate a PWM signal to the new ground level. Does there exist a easier method than the following? (Ideally with ...
0
votes
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
votes
2answers
121 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
votes
2answers
164 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 ...
-1
votes
1answer
92 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 ...