Outstanding. Very thorough presentation in a short period of time.

man I was stumped in my project until I came accros your video! thank you for being smart sir and for your videos! I appreciate them

It would be interesting to see some linear opperating mode optocoupler circuits. I believe hotchassis TVs used to use optocouplers for AV input isolation, and switch mode supplies using optocouplers for feedback of output voltage levels to the primary side controller. It would be interesting to see the schematics of such circuits.

great explain thank you Mr LEWIS

Dear Mr Lewis, Thank you for such a wonderful lesson. I managed to finish my masters project with the help of this knowledge..!! Thank you again.

Excellent, thank you. I will definitely be checking out your other videos.

Wow, VERY nice tutorial. Thanks!

Thank you so much for providing this lesson. I tried getting into Arduino years ago, but didn't have an understanding of how even transistors worked, or how they were special. How that figured into CPU design and other applications. Now I'm slowly building on that knowledge so I know how the chips and boards work, aside from the actual ATMega328 and the way it is programmed.

I enjoyed watching. Great, instructive content !

Hi there, Lewis, great tutorials head's up!!!

New related video OptoCoupler Interfacing H-Bridge Circuits kzfaq.info/get/bejne/jtCiasd3zZnQiY0.html

very informative episode, I wonder what is the maximum frequency tha optocoupler can be oprated, cause I was thinking to use it on a high voltage switching power supply control around 200 KHz

Nice practical theory great teaching good work

what type of transistor is most efficient? as far as power consumed or lost, is a MOSFET more efficient than like a Darlington. of BJT or IGBT? I'm asking because I'm looking for the best switch to use in pwm battery powered apps. for longer run time. thanks for great videos.

Looking forward to see how to pwm an ac load! Most ssr's cant handle pwm with out over loading, and the ones that can are really expensive. Any suggestions for pwming a 120 volt light source. Thanks for the great videos.

Thanks I like the circuit in 2:16 and I guess I will be using it to protect it in general and not just for relays. What do you think?

very good presentation thank you

Good presentation thank you

great video, and thanks for the schematic :)

Thanks a lot! Been looking for this.

Great video but I have a question, is it possible to invert the output of the opto iso;lator? example i need a circuit where the output transistor is switching a motor but the motor goes off when the opto is operated as opposed to the motor going on when the opto is isolated. I guess there is a way but i am not sure how to apply it.

thanks for your time dedicated

can i use this opto to take pwm and control the firing angle of the triac

Do you have any more detail on the protection circuit or sources to check out? Theory of operation, how to pick values and components? I'm looking to build a circuit to accept a 30-300V variable HZ AC (two legs of a three phase alternator) input to a 5V square wave. I'm thinking build around a H11L1 and my best idea before that was to try a capactive coupling against the positive output of the rectifier.

Beautiful. Its all about to isolate the load that is driven by the arduino command. But what input isolation. How to ise it opposite?

Here is how to use photovoltaic optocouplers: High Voltage IGBT H-Bridge Using Photovoltaic Optocouplers kzfaq.info/get/bejne/l-B6opeZksvNZn0.html webpage: www.bristolwatch.com/ele4/index.htm Exploring Photovoltaic Optocouplers used as MOSFET Drivers kzfaq.info/get/bejne/ntGDipuItpqnk40.html

Good stuff.

thanks for the info sir

thank you very much

thanks dear Sir, you rescued me

Awesome!

You are great man

Very informative. Thanks for sharing!

guess I'm doing something wrong, trying to cycle a pair PNY17-1 with a 555, and I can not get any voltage through the couplers. tried a few different ones. Great video though.

5v to 24 v optocoupler circuit diagram. Using encoder output 5v to PLC 24 v converter

thank you sir

Thanks appreciated and subscribed

Great video! How did you size the 220ohm resistor on the input side of the 5vdc circuits?

you have a lot of great tutorials Lewis

Hello Lewis, first of all, I would like to thank you for those awesome videos. I am new to electronics and whatever I've learned so far, thats thanks to you. But I was wondering one point. The max collector current is, lets say 100 or 50 mA of the optocoupler, in the schematic kzfaq.info/get/bejne/apZopM-El-Caqac.htmlm44s, isn't a current limiting resistor required?

I have minus 130volts pulsing that needs to turn on P channel MOSFET with load on ground side ,through optocoupler 4N25. Can I use diode to reduce the negative volts down, and then use step down voltage divider LEVEL SHIFTING CIRCUIT to change polarity to positive low volts to input of optocoupler IC ? Can the input negative volts go to the diode cathode of opto?

Nice video. So Lewis, the only circuit here that will do PWM is the "Basic NPN transistor solid state DC relay"? I want to isolate a PIR sensor and an Arduino from a 9g relay because the relay seems to be affecting the sensor. Can I still run a wire from an IO pin on the Arduino to the servo so that I can control it?

Can this be used in the opposite direction. That is to say, I would like to use a 24v proximity switch, through an optocoupler to signal a pin on the arduino @5v (or take the 5v signal to ground)

You get that proto-board from dealextreme? I bough some, but hadn't had time to test those out, are they any good?

What is the function of the 1k resistor between the emitter of the 4n25 and the base of the TIP120 ?

Ja ,etwas in Richtung Perfekttransistor ist egal Tip npn oder PNP ,OK auf jeden Fall richtig

good morning mr lewis whats the difference between a Pnp transistor like tip120 and the N channel mosfet ... and how can we assure that Vcc doesnt not exceeds vgs thx in advance

I have a problem with opto isolator in my circuit it is still respond to command but only give weak current output around 2ma. I connect the output to drive 12v relay. Why is like that?

Is the output resistor connected to the 4N25 just to ensure that the maximum current will not exceed 150mA?

Why do we need the additional transistor / mosfet? Why isn't the octocoupler enough to open/close the bulb to source circuit?

so is the main purpose of the optocoupler to provide isolation ?

I highly recommend investing in a better mic for your voice over. :)

Isn't there a different current limiter for the input instead of a crowbar circuit without the 2W resistor?

######!!Don't I need 2 bipolar transistors to shut off the P channel? (no mechanical switch to disconnect ground) I need optocoupler + 2nd transistor to shut off P channel as used as HIGH SIDE SWITCHING.???????

10:58 What is the use of 10k ohm resistor between the gate and anode 1 terminal of triac?

Ich teste das

Can optocouplers be used for high power rating?? 3KVA????

New see: www.bristolwatch.com/ele3/ele6.htm Optocouplers for TTL-CMOS Logic Level Shifting

what are the part numbers of Mosfet?

Could this be used to convert 24VAC to logic level signals?

what is better optocoupler or mosfet ?

👍👍👍👍👍!

how to latch circuit pls with OCP

Sir instead of tip120 Can I use tip 127

One can't use PWM with an AC circuit. You have to sync to the AC waveform then switch on an SCR or triac between half cycles. I'll have that coming up.

So why noone on the internet have never built dc dc buck 100v 100A?? Maximum I ever seen is buck 55v 22A

Solar Charge controller

Mal sehen was wir haben

Silly, did not even mention CTR once!!!!!!!!!!

oYEEAAA send my SEMIconductor SIMULATER_eagle Autoroute_ ?? what a GUESS?? isn`t it??

Ich sage nur wellenvormen und ich weiß was ich da mache,es ist kein Optokoppler

thank you sir