How Optocouplers work - opto-isolator solid state relays phototransistor
video description
Date: 2023-11-17
Related videos
Comments and reviews: 27
Songfugel
The explanation after 13: 50 makes little to no sense, since you are introducing a mystery component Receiver, which you don't explain at all. It doesn't seem to work as a IR fotoresistor, and it isn't an emitter, so why is it calculated as an IR emitter? Is it in fact an IR activated transistor? If possible, could you (or someone) please either explain how this works, or point to some materials that explains the workings of this receiver that works like in this diagram.
Also, why are the receiver stats looked up from the emitter graph?
I am lost, after wasting hours trying to find anything even remotely clear information about this topic, I could only find wildly contradicting articles. If anyone can explain this to me, or point me to the right direction, I would greatly appreciate it
Edit: For anyone else interested, I got our University's Electronic's Professor to explain it to me. In the tutorial, he is suddenly changing into a photodiode setup instead of photoresistor, and using the photodiode in reverse!
So this photodiode will act as a normal diode in dark, however, unlike normal diodes, it will allow current to pass both ways when hit with the foton particles.
And since it is reversed in this case, it will block all current, until it is bombarded with fotons. It also has a dark semi-transparent shielding on it, that will block the unwanted wave frequencies, and will act as the switch here-
reply
The explanation after 13: 50 makes little to no sense, since you are introducing a mystery component Receiver, which you don't explain at all. It doesn't seem to work as a IR fotoresistor, and it isn't an emitter, so why is it calculated as an IR emitter? Is it in fact an IR activated transistor? If possible, could you (or someone) please either explain how this works, or point to some materials that explains the workings of this receiver that works like in this diagram.
Also, why are the receiver stats looked up from the emitter graph?
I am lost, after wasting hours trying to find anything even remotely clear information about this topic, I could only find wildly contradicting articles. If anyone can explain this to me, or point me to the right direction, I would greatly appreciate it
Edit: For anyone else interested, I got our University's Electronic's Professor to explain it to me. In the tutorial, he is suddenly changing into a photodiode setup instead of photoresistor, and using the photodiode in reverse!
So this photodiode will act as a normal diode in dark, however, unlike normal diodes, it will allow current to pass both ways when hit with the foton particles.
And since it is reversed in this case, it will block all current, until it is bombarded with fotons. It also has a dark semi-transparent shielding on it, that will block the unwanted wave frequencies, and will act as the switch here-
reply
dwjw1
Very complete and concise presentation.
I noticed one thing about PC817 though that surprised me. You show the pins 1, pin 2 on one side and pin 3, pin 4 on the other. According to the Sharp datasheet, pin 3 should be pin 4 and pin 4 should be pin 3. That is, the pins are numbered down one side and up the opposite side, not both sides from top down. Not sure that will cause anyone too much heart burn, but.
reply
Very complete and concise presentation.
I noticed one thing about PC817 though that surprised me. You show the pins 1, pin 2 on one side and pin 3, pin 4 on the other. According to the Sharp datasheet, pin 3 should be pin 4 and pin 4 should be pin 3. That is, the pins are numbered down one side and up the opposite side, not both sides from top down. Not sure that will cause anyone too much heart burn, but.
reply
dax3m
I can't tell you how grateful I am for making these videos; I have a hard time accepting this does that without an explanation of the underlying foundations of why it does that. Your explanation down to physical properties of the material is precisely what makes me go oh! that's why! and what I've been looking for all this time I've been trying to learn electronics. Keep up the amazing work and thank you!
reply
I can't tell you how grateful I am for making these videos; I have a hard time accepting this does that without an explanation of the underlying foundations of why it does that. Your explanation down to physical properties of the material is precisely what makes me go oh! that's why! and what I've been looking for all this time I've been trying to learn electronics. Keep up the amazing work and thank you!
reply
siamsurf
The animations sometimes show electricity flowing from the positive to the negative terminal of the battery, however, it actually flows in the exact opposite direction. 3: 45 has the electricity flowing from + to - and from - to +, so I guess you never intended to show how electricity flows in the real world, which is kinda sad, considering how awesome the rest of the video and explanation is.
reply
The animations sometimes show electricity flowing from the positive to the negative terminal of the battery, however, it actually flows in the exact opposite direction. 3: 45 has the electricity flowing from + to - and from - to +, so I guess you never intended to show how electricity flows in the real world, which is kinda sad, considering how awesome the rest of the video and explanation is.
reply
Paul
Thick film resistors have a 25KV rating, this optocoupler circuit will arc over before that. A thick film 2W resistor on both power lines followed by clamping diodes is lightning proof and if you short the signal lines on the board it has no effect on the supply line. Optocouplers are crap, they have a rise time in microseconds compared to the nanoseconds with not using them.
reply
Thick film resistors have a 25KV rating, this optocoupler circuit will arc over before that. A thick film 2W resistor on both power lines followed by clamping diodes is lightning proof and if you short the signal lines on the board it has no effect on the supply line. Optocouplers are crap, they have a rise time in microseconds compared to the nanoseconds with not using them.
reply
Anthony
Listen my guy. I have looked far and wide. just got started with Arduinos, esp8266, and raspberrypi. I understand the mechanical side, the software side, but just couldn't find a well versed and exampled documentary on how circuitry works. on how to calculate the resistance needed and everything all in one video. This is genuinely GOLD man. This makes sense. Thank you
reply
Listen my guy. I have looked far and wide. just got started with Arduinos, esp8266, and raspberrypi. I understand the mechanical side, the software side, but just couldn't find a well versed and exampled documentary on how circuitry works. on how to calculate the resistance needed and everything all in one video. This is genuinely GOLD man. This makes sense. Thank you
reply
drlegendre
When discussing optocouplers, it's a good idea to mention Vactrols aka resistive optoisolators. They aren't ofren used these days in new designs, but in the past they were widely used in audio gear like guitar effects and analog synthesizers. Since these are both popular topics, DIYers are likely to encounter the Vactrol sooner or later.
reply
When discussing optocouplers, it's a good idea to mention Vactrols aka resistive optoisolators. They aren't ofren used these days in new designs, but in the past they were widely used in audio gear like guitar effects and analog synthesizers. Since these are both popular topics, DIYers are likely to encounter the Vactrol sooner or later.
reply
Adrian
You have numbered the pins incorrectly at about 0: 35. Pin 3 and 4 are should be the other way around with pin 3 at the bottom right and pin 4 at the top right. I know that might seem pedantic but it's important to get numbering systems correct, especially when dealing with ICs.
reply
You have numbered the pins incorrectly at about 0: 35. Pin 3 and 4 are should be the other way around with pin 3 at the bottom right and pin 4 at the top right. I know that might seem pedantic but it's important to get numbering systems correct, especially when dealing with ICs.
reply
Jose
Question, i have 380VDC output from a solar inveter i am building and i need to light up the ired diode inside anEL817 opto, as a feedback voltage control, what is the best way to do it? with resistors and a 10K pot or with Zeners? this is with an SG3525+LM358 +EL817 board
reply
Question, i have 380VDC output from a solar inveter i am building and i need to light up the ired diode inside anEL817 opto, as a feedback voltage control, what is the best way to do it? with resistors and a 10K pot or with Zeners? this is with an SG3525+LM358 +EL817 board
reply
CS
Today I wanted to know how optocouplers worked. Dont actually need to but it intrigued me. I can safely say THIS is the best video explaining it. Thank you for the calculation of resistor values as well as the real life examples of being able to add them up.
reply
Today I wanted to know how optocouplers worked. Dont actually need to but it intrigued me. I can safely say THIS is the best video explaining it. Thank you for the calculation of resistor values as well as the real life examples of being able to add them up.
reply
Roy
Your pinouts do not match the manufacturers data sheet. The pin1 by the dot is correct and the numbering goes CCW. Your emitter and collector pin numbers are wrong but the descriptions are correct. Excellent technical description otherwise.
reply
Your pinouts do not match the manufacturers data sheet. The pin1 by the dot is correct and the numbering goes CCW. Your emitter and collector pin numbers are wrong but the descriptions are correct. Excellent technical description otherwise.
reply
Timm
Surely, this video shows pins 3 & 4 the wrong way round? On any IC you count down the marked side and then up the other. However, the collector and emitter are shown correctly.
reply
Surely, this video shows pins 3 & 4 the wrong way round? On any IC you count down the marked side and then up the other. However, the collector and emitter are shown correctly.
reply
Anthony
if i hooked one lead of the receiver to gnd and the other to an arduino would that let me set a low signal to one of the pins or does the receiver need a current to close?
reply
if i hooked one lead of the receiver to gnd and the other to an arduino would that let me set a low signal to one of the pins or does the receiver need a current to close?
reply
Byron
You can also use them to isolate analog signals from their sources. Generally, negative feedback is needed to keep the bias at the optimum level and the gain predictable.
reply
You can also use them to isolate analog signals from their sources. Generally, negative feedback is needed to keep the bias at the optimum level and the gain predictable.
reply
prathaban
with optocoupler in between PLC and grounded thermocouple(J type, can we get a proper signal in PLC. will it eliminate the ground loop btw the PLC and thermocouple?
reply
with optocoupler in between PLC and grounded thermocouple(J type, can we get a proper signal in PLC. will it eliminate the ground loop btw the PLC and thermocouple?
reply
Karabo
Awesome video. You make it seem like a walk in the park. Should I have come across your content during my school days I was going to ACE most modules.
reply
Awesome video. You make it seem like a walk in the park. Should I have come across your content during my school days I was going to ACE most modules.
reply
Ousmane
Hello Engineering Mindset can i use your video to reuse it into french version by muting your voice and and mine for more explaination in french
reply
Hello Engineering Mindset can i use your video to reuse it into french version by muting your voice and and mine for more explaination in french
reply
cryzz0n
The Optocoupler was my favorite device for keeping low/high voltage apart. Use to use it to drive Triacs with it for light shows. Great video
reply
The Optocoupler was my favorite device for keeping low/high voltage apart. Use to use it to drive Triacs with it for light shows. Great video
reply
Thomas
[13: 10] the diagram shows 2 resistors with 270ohm and 220ohm instead of 270ohm and 22 ohm.
Very good and informational Video!
reply
[13: 10] the diagram shows 2 resistors with 270ohm and 220ohm instead of 270ohm and 22 ohm.
Very good and informational Video!
reply
AGS-TECH
I love this video. Very clear and instructive. Animations of current moving makes it easy to follow. Thank you for posting!
reply
I love this video. Very clear and instructive. Animations of current moving makes it easy to follow. Thank you for posting!
reply
At
I LOVE THIS TYPE OF CONTENT! Great work Paul!
Can you make a video on other types of optocouplers? it would be helpful too.
reply
I LOVE THIS TYPE OF CONTENT! Great work Paul!
Can you make a video on other types of optocouplers? it would be helpful too.
reply
Time-Trvlr
IR LED can be seen with most phone camera / displays, Apple iPhone have filters so do not display LED operation.
reply
IR LED can be seen with most phone camera / displays, Apple iPhone have filters so do not display LED operation.
reply
Linh
There's a slight mistake at around 13: 20 where you put 220 ohms instead of 22 ohms. Overall, I like your video a lot!
reply
There's a slight mistake at around 13: 20 where you put 220 ohms instead of 22 ohms. Overall, I like your video a lot!
reply
spicky
Hummm guess you cant use MMeter to test this alone-Where in the datasheet it says the emitter=1. 2V and 0. 02A
reply
Hummm guess you cant use MMeter to test this alone-Where in the datasheet it says the emitter=1. 2V and 0. 02A
reply
Mark
This is by far the most educative approach regarding optocouplers!
Thank you so much for Engineering Mindset
reply
This is by far the most educative approach regarding optocouplers!
Thank you so much for Engineering Mindset
reply
Tony
Paul, you do realise when you said youre using a 22 ohm resistor 13: 59, a supposedly 22 ohm resistor shows 220
reply
Paul, you do realise when you said youre using a 22 ohm resistor 13: 59, a supposedly 22 ohm resistor shows 220
reply
Andrea
This is THE most interesting video i've found on this subject so far! Really well explained
Thank you!
reply
This is THE most interesting video i've found on this subject so far! Really well explained
Thank you!
reply
Add a review, comment
Other channel videos
