An optoelectronic device which combines an optical transmitter and receiver in a single package; commonly used in galvanic-isolated control applications such as power supplies.

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37 views

220v buzzer causing pic to reset

i'm using this circuit to drive an AC 220v buzzer which cause my pic microcontroller to reset (which does not happen using a lamp), i currently use the following set up which helped me with the ...
1
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3answers
105 views

Optoisolator, did I connected it right? (Arduino Uno)

Here is my connection for optoisolator, 2 wires, yellow and red are for AC current. Other 3 in my arduino, orange pin 2, blue ground and red 5V power. And ...
0
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2answers
108 views

How to test if zero crossing is working?

I used circuit like this: On led I get: 3.3 mA and 1.3V What is the best way to test if zero crossing works with arduino or multimetar?
1
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2answers
219 views

Driving a 24V isolated load from a 3.3V MCU

I am looking to drive a 12-24V purely resistive load from a 3.3V MCU. I would like to use an opto-isolator to separate the circuits electrically. I've drawn up the following circuit, but I'm not ...
1
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1answer
83 views

Using optocoupler with MOSFET for dimming a LED

I have a blue LED which I want to dim using an Arduino, an optocoupler and an N-MOSFET. For achieving this I assembled the circuit on a breadboard as shown in the pictures, using a YwRobot breadboard ...
1
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2answers
54 views

Optoisolator Long term Reliability at HVDC

Most optocouplers spend most of thier time isolating mains voltages.They are reliable doing this and they are cheap and simple.How would things go if the same garden variety opto was isolating a DC ...
0
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1answer
41 views

Arduino input with CNY17 to sense 12v input

I have an Arduino Due and i am using a CNY17 optocoupler to sense a 12v brake signal from a car. The 12v signal is going thru a 1K resistor to the opto on pin 1, pin 2 to the ground. 3.3v is going ...
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2answers
46 views

Optocoupler w/ RasPi & Door Buzzer

I'm currently trying to make a system where sending a message to my Raspberry Pi from my phone will send a signal to my apartment's buzzer to open the front door, however I've been having problems ...
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39 views

why is there a dc shift in the output of the opto-isolater?

I have pc817 ...input is 0 to 5 v and the output is 0 to 5v with dc shift. pin 1 and 2 is connected to an arduino with a resister on pin 1 150ohm pin 3 ground and pin 4 resister 150ohm + Vcc 5v.. so ...
2
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1answer
50 views

4N32 Opto-Isolator Questions

I am looking into using a 4N32 opto-isolator and am struggling to find information on its pin 6. This looks to be the base of the transistor (darlington). I see example circuits where they appear to ...
2
votes
1answer
82 views

How Zero Crossing optoisolator to work with 220VAC?

I want to use a H11AA1 to detect Zero Crossing, but I am not sure how circuit should look like. How much voltage should LED receive inside H11AA1? Here is datasheet: ...
0
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3answers
114 views

Optocouplers with non-inverting logic

Here is the setup: I'm using the Arduino Mega's SPI functionality to send signals to multiple DACs. For digital isolation, I am considering the HCPL-2631 or the ACPL-064L. The problem with these two ...
0
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0answers
37 views

what is the best way to protect sinking inputs

I have a controller with sinking inputs ( should be grounded to activate) , I will use the system in a noisy environment, I want to protect these inputs from EMI and voltage spikes, what is the best ...
1
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1answer
48 views

Power rating for opto-triac trigger circuit resistors

RHS will be using 220v 400watt bulb 2 simple questions 1- does the 360ohm resistors has to be of high watt too ? 2- all i can find is 5-10watt resistors, can i use them ? would they snub correctly ...
0
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2answers
42 views

Opto Coupler output voltage drop when connected to PLC

I have an input of pulse width 5 ms and which is fed to a Buffer IC and then the output of the buffer is FED to an opto isolator whose collector is pulled with a pull up of 7.5k resistor with an 24 V ...
0
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0answers
50 views

220V AC Light Dimming(triac H11AA1, MOC3052-M)?

Could I use triac H11AA1 and MOC3052-M to control 220VAC with arduino? I am new to electronics and I am not sure if that components can handle the voltage... Also could you show me some circuit with ...
0
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3answers
60 views

Using an opto-isolator in a car's circuit. How to ground?

So I have a microcontroller that will read some of the car's sensor output (0-5v) and i plan to send the signals through an opto-isolator. The problem is that when i simulate this, it seems i cannot ...
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2answers
5k views

Need help with 90vdc PM motor speed control circuit

I recently found a Permanent Magnet 90vdc motor, 2.5hp, 18Amps. It has simply two wires for voltage (red/black) and two for thermal breaker circuit i believe (blue/blue). It came out of an old ...
0
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0answers
59 views

How to control AC high voltage with Arduino?

I found this great post: http://majsterkowo.pl/en/how-to-control-any-home-appliance-using-a-tv-remote-and-an-arduino/ and this scheme: ...
0
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2answers
60 views

Optocoupler Question

I'm currently trying to create a system to open my apartment's door (using the buzzer) using my raspberry pi, and thought that using an optocoupler would be the best solution - although I'm a complete ...
1
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1answer
94 views

uC-controlled high-side switch

I designed a circuit that powers on when the car is started (key is in ACC or ON). The circuit's uC then enables 12V from the battery by setting port PC5 high. The uC detects when the key is ...
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1answer
40 views

Totem pole opto-isolator TLP152 won't work as intended

I've been working on this very confusing problem regarding making a TLP152 opto-isolator to work as intended. Here is my circuit using a TLP152 to work as a IGBT gate driver. TLP152 circuit diagram ...
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2answers
44 views

Exceeding _Enable input voltage_ of optocoupler

I have microcontoller board with following optocoupler interface which is obviously made for input up to 5V. Based on datasheet I found, Vf = 1.5 V and ...
0
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3answers
90 views

Recommended capacitor rating for this mains zero-crossing detector

I found this zero-crossing detecting circuit here I want to recreate it, using the parts that I have on hand (or can get cheapest), but I'm not sure how to choose the correct 0.1uF capacitors. ...
3
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2answers
81 views

Timing Issues with Optically Isolated Data Signal

I have been working on a system that requires data transmission between two devices powered by separate supplies. I have based my design on the MIDI-hardware Spec, as I'm comfortable working with that ...
0
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2answers
111 views

optocoupler output protection

I've got this circuit. The target generates an identical PWM signal to control the intensity of 3 LEDS. But I would like to protect the output of these optocouplers with this TVS: I'm not sure if ...
0
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4answers
97 views

Opto-coupler output

I am using this circuit for mains detection: The output fluctuates a little but capacitor and resistor values ensure that Output is logic HIGH when 220V mains is present. Once mains is not ...
0
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1answer
60 views

Hey I am using 2 4N35 Optocoupler from Visha can I replace them with a single ILD615 from Vishay?

I went through both datasheets and i think it should work. Basically I am asking if the dual channel version of 4N35 is the 8 dip ILD615. Thanks. edit: I have added the picture. my circuit is like ...
14
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1answer
16k views

Criteria behind selecting pwm frequency for speed control of a dc motor?

I'm working on a speed control circuit for a brushed dc motor (24v, 500rpm, 2A, 4kgcm). The main components that I plan to use are PIC16f873, 4n25 optocoupler, IRFZ44N MOSFET, BY 500 - 800 diode(for ...
0
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1answer
39 views

normally open or normally closed OptoMos

In the following OptoMos datasheet the OptoMos is defined as Normally closed, when there is no input the output is closed. But in other OptoMos like the SFH618A-2 i can't find if the OptoMos is NO or ...
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3answers
2k views

How can I use optocouplers with function generators?

I am using optocoupler PC817 to create optical isolation between my digital signal and arduino due and arduino mega 2560 . And I am using external pull-up resistor connected with 3.3 V (to pull up ...
1
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1answer
59 views

How to use same 'input' for two circuits

First of all, please excuse my complete lack of knowledge in electronics :) Let's start with a little bit of context. I am trying to modify a machine that already uses a photo-interrupter to measure ...
0
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1answer
81 views

Converting 5 volts to 12 volts using a photocoupler

i have an arduino and i need to convert 5 volts to 12 volts in order to trigger a 12 volt Rele, i am considering to use the circuit that i attached here (below), if the "input" square is 5 volts, what ...
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4answers
2k views

I2C optocoupler separation - which IC?

I am designing a circuit which will have some external I2C sensors connected to it and thus I want to protect it from noise - via an optocoupler. I have to say that I am a complete novice to this all ...
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0answers
39 views

Adding resistor in parallel to digipot

I'm trying to control a device using a digital potentiometer (AD5245S). In my application I can't tie the low-ref of the potentiometer and ground, so I'm using an I2C optical isolator (ISO1541) to ...
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2answers
37 views

Do I need TVS with Optocoupler relay

I am connecting digital output from a camera to a light source using a relay (see below). The relay uses SONGLE SRD-5VDC-SL-C Optocoupler: RELAY DATASHEET The camera manual says "Uses an ...
0
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1answer
28 views

Optical switch operation point derivation

I have an optical switch part opb840W and I am failing to derive the required information for my application from there. The intended use would be as in the following circuit: simulate this ...
5
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2answers
134 views

Opto-isolator output from collector vs. emitter

I have an Isocom ISQ2X quad opto-isolator (datasheet) that I will use to drive a logic input. The opto-isolator's simplified model given by the datasheet is pictured below. The transistor base pin is ...
3
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1answer
99 views

Voltage Regulation

I am a young engineer and I need a help from you. I need to design a driver circuit which must power-up a LED (OC) if the measured volatge is greater that 50V (Voltage to be measured can be upto ...
0
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1answer
69 views

OptoIsolator Reliability?

I have heard it from multiple people over the last 5 years that Optoisolators are failure prone and should be avoided when able. I'm working on a project (for personal use) that I was going to put an ...
0
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2answers
70 views

Severe Voltage Drop When Applying a Load to Opto-Isolator Circuit

The circuit below uses the Vishay ILD213T optocoupler (datasheet). The load in question is a 5V solenoid valve with a resistance of 46Ω. The circuit is configured with "IN1" connected to a GPIO pin ...
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2answers
98 views

Use a PC123 optocoupler for MIDI input

Im trying to connect a MIDI input cable to an arduino. To do that, I need an optocoupler, that secures the internal circuits from damage. This is the schematic as shown by the MIDI specification: ...
2
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2answers
82 views

Design of AC measurement circuit

I posted a question earlier, How to measure AC voltage without a voltage divider using microcontroller and I got some very useful answers, one of those was to implement this for isolation ...
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2answers
1k views

How do I select an optoisolator to both provide zero crossing to a uC and controll a triac?

This application note states that zero crossing detection can be achieved in an AVR with just a couple of resistors. However, it forgoes galvanic isolation and this is not acceptable for me. I would ...
4
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2answers
410 views

What is the correct way to measure voltage with an optocoupler?

I'm using an optocoupler to measure a voltage, I'm making a current loop to control the current through the LED, so I'm using three op-amps: one to measure the voltage, one to set up a current offset ...
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2answers
193 views

Triac - opto-coupler Circuit Confusion

I have the following question regarding this circuit: How is the opto being used to trigger the base of the triac?The collector of the photo-transistor is connected to the base of the triac. As per ...
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1answer
52 views

Accidentally outputting to an optoisolator

It's your friendly electronic hobbyist again. I am designing a board where I am reading input from an optoisolator like this. IN7 is connected to a peripheral parallel port chip of an old 8-bit ...
0
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3answers
82 views

Isolated mosfet switching circuit

I have designed the circuit below for a isolated digital output from a mcu. The switching speed is slow -- only 100ms or so. I would like to be able to switch between 3 and 24Vdc at about 1mA to ...
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2answers
98 views

Combining Optoisolator and Relay into one I/O pin

I have a project that uses two microcontroller pins to control the input and output of an isolated device. The LEDs are for status, showing when an input or output is enabled. I'd like to save some ...
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5answers
285 views

Very wide range high voltage measurement with optical isolation

I have a voltage source I'd like to measure, it is from 0V to 1kV, any value in that range. The accuracy isn't that important, but measuring with an accuracy with 1-5% would be perfect. This has to be ...