All Questions
Tagged with sensing opto-isolator
8 questions
2
votes
5
answers
278
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How to sense the presence of AC voltage that could vary from 17 V to 230 V?
I have a requirement to sense the presence of AC voltage, that could vary from 17 V to 230 V, and trigger a TLPxxx series optocoupler.
The wide voltage range poses a problem in the choice of a ...
1
vote
1
answer
186
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Are 4N35 optocouplers clamped at 22V?
I am trying to detect mains with an ESP32, for that I started testing this circuit:
I bought a 4N35 optocoupler and 110kΩ resistors.
My first test was using 2 resistors in series, so R1 = 220kΩ.
The ...
- 1,256
0
votes
0
answers
601
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4N35 opto isolator with ESP32
I had an old Arduino setup where I used this chip to interface with another circuit which had some LEDs. The goal of the project was to signal the Arduino if the external circuit turned an LED on.
In ...
user106458
0
votes
1
answer
64
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Verifying electric brake current with opto-isolated feedback
I would like to find a way to sense (or detect) current through an opto-coupler.
This opto is used to power an electromagnetic brake, but depending on the type of brake the current through it can ...
- 111
3
votes
2
answers
2k
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HCPL3700 - 220V sensing circuit
I want to use HCPL3700 optocoupler for sensing 220V (line).
I design a circuit but I want to ask some questions.
HCPL3700 is an open-collector output so I pull-up Vout. In AC voltage sensing some ...
0
votes
1
answer
389
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Sense 230V - voltage
Brief sum up (you can go directly to the end if you already read the sum up in the other question)
For a home project I'm making a controller to drive a two-direction 230V motor. For those unfamiliar ...
- 1,240
4
votes
1
answer
29k
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AC Optocoupler for 230V line detection
I am trying to detect line voltage (230V AC, if the supply is ON/OFF) by a microcontroller with the help of an AC optocoupler. The optocouplers I have evaluated are PC814, H11AA1 and SFH620A-3, out of ...
- 442
1
vote
2
answers
2k
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220 VAC detection using Optocoupler
I tried to detect 220V AC in my microcontroller using SFH620A-3 with series resistance of 440K (2 x 220K, 1/4 watts SMD type), a 1uF at the output to smoothen the pulse and every works as expected. ...
- 442