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.
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.
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?
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.
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.
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 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?
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.
######!!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.???????
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
They are very different devices one current operated while MOSFETs are voltage operated. See this page on MOSFETs: www.bristolwatch.com/ele2/mosfet_relay.htm
Here is how to use photovoltaic optocouplers: High Voltage IGBT H-Bridge Using Photovoltaic Optocouplers ruclips.net/video/azJo4h-ei6I/видео.html webpage: www.bristolwatch.com/ele4/index.htm Exploring Photovoltaic Optocouplers used as MOSFET Drivers ruclips.net/video/hkSW8WQ4CcY/видео.html
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)
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?
Yeah. I wanted to write 15mA (~16.4mA), sorry. In a practical project, can I consider the CTR specified on the datasheet? Or does it may have a large variation?
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.
You all prolly dont give a damn but does any of you know of a method to log back into an instagram account? I stupidly lost my account password. I would love any assistance you can give me.
@Dustin Demetrius Thanks so much for your reply. I got to the site through google and im trying it out atm. Looks like it's gonna take quite some time so I will get back to you later with my results.
@@LewisLoflin Thank you for your prompt reply. In addition to solving my current project's needs, I'm very interested in learning how to understand and do this correctly. Do you know of any resources that I might look to to better understand how to properly design a circuit that will convert 24VAC to 3.3VDC?
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.
Thank you for your truly awesome and explanatory videos! Can I ask what if an IGBT is used instead of an SCR? Would this work in combination with an opto coupler controlled by Arduino/555 which would be sending the PWM signals?
Not sure I can answer I don't know the particular structure of the device. Just looked this up an a DC device opto-couplers will work as long as the voltage isn't too high on the opto-coupler.. www.ixys.com/documents/appnotes/ixys_igbt_basic_i.pdf
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 ruclips.net/video/408qlS2z6ys/видео.htmlm44s, isn't a current limiting resistor required?
![Blox Fruits Dragon Rework Update [Full Stream]](http://i.ytimg.com/vi/EqDAp8udhm0/mqdefault.jpg)
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.
You are why I put this information here. Good luck.
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
That's what I've been looking for.Many thanks🙂
Outstanding. Very thorough presentation in a short period of time.
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.
Arduino Uno 👍
Schön jemanden zu treffen der gute Ideen hat
Thank you
Beautiful. Its all about to isolate the load that is driven by the arduino command. But what input isolation. How to ise it opposite?
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.
10:58 What is the use of 10k ohm resistor between the gate and anode 1 terminal of triac?
Forms a voltage drop across MT1 and gate.
@@LewisLoflin Thanks, I have the same project in school that uses BT136 triac. (AC LIGHT DIMMER)
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?
I enjoyed watching. Great, instructive content !
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?
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.
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.
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
Why do we need the additional transistor / mosfet? Why isn't the octocoupler enough to open/close the bulb to source circuit?
Opto-couplers are usually limited to 100mA.
Isn't there a different current limiter for the input instead of a crowbar circuit without the 2W resistor?
You can use any current limiter.
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?
For efficiency can I use a MOSFET instead, over on the right hand side of the diagram?
Great video! How did you size the 220ohm resistor on the input side of the 5vdc circuits?
Yes
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.
Nice practical theory great teaching good work
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.
######!!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.???????
No. The 10K resistor will charge the gate back to +Vcc. It will switch on with a difference in voltage on the gate source.
Ja ,etwas in Richtung Perfekttransistor ist egal Tip npn oder PNP ,OK auf jeden Fall richtig
Excellent, thank you. I will definitely be checking out your other videos.
Thanks.
great explain thank you Mr LEWIS
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
They are very different devices one current operated while MOSFETs are voltage operated. See this page on MOSFETs:
www.bristolwatch.com/ele2/mosfet_relay.htm
thx a lot for your help
Here is how to use photovoltaic optocouplers:
High Voltage IGBT H-Bridge Using Photovoltaic Optocouplers
ruclips.net/video/azJo4h-ei6I/видео.html
webpage: www.bristolwatch.com/ele4/index.htm
Exploring Photovoltaic Optocouplers used as MOSFET Drivers
ruclips.net/video/hkSW8WQ4CcY/видео.html
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)
+Christopher Pearsall Should work.
so is the main purpose of the optocoupler to provide isolation ?
Yes. It is used also for interfacing.
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?
Not sure what you mean. Be more specific.
Wow, VERY nice tutorial. Thanks!
thanks for your time dedicated
Is the output resistor connected to the 4N25 just to ensure that the maximum current will not exceed 150mA?
Should not exceed 20 mA. Are you referring to the one on the opto-coupler LED?
Yeah. I wanted to write 15mA (~16.4mA), sorry. In a practical project, can I consider the CTR specified on the datasheet? Or does it may have a large variation?
what are the part numbers of Mosfet?
See this webpage: www.bristolwatch.com/ele/h_bridge.htm
Hi there, Lewis, great tutorials head's up!!!
What is the function of the 1k resistor between the emitter of the 4n25 and the base of the TIP120 ?
Limits base current of TIP120.
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.
you have a lot of great tutorials Lewis
You all prolly dont give a damn but does any of you know of a method to log back into an instagram account?
I stupidly lost my account password. I would love any assistance you can give me.
@Devon Sam Instablaster ;)
@Dustin Demetrius Thanks so much for your reply. I got to the site through google and im trying it out atm.
Looks like it's gonna take quite some time so I will get back to you later with my results.
@Dustin Demetrius it did the trick and I finally got access to my account again. I am so happy!
Thanks so much, you really help me out :D
@Devon Sam happy to help :D
can i use this opto to take pwm and control the firing angle of the triac
Could this be used to convert 24VAC to logic level signals?
No this is for DC. You would have to rectify/filter the AC (1.41 X VAC) and use a larger dropping resistor.
@@LewisLoflin Thank you for your prompt reply. In addition to solving my current project's needs, I'm very interested in learning how to understand and do this correctly. Do you know of any resources that I might look to to better understand how to properly design a circuit that will convert 24VAC to 3.3VDC?
5v to 24 v optocoupler circuit diagram. Using encoder output 5v to PLC 24 v converter
You are great man
You get that proto-board from dealextreme?
I bough some, but hadn't had time to test those out, are they any good?
I built it. I put together 2 strip boards available anywhere glued to a scrap fiber glass base.
great video, and thanks for the schematic :)
Can optocouplers be used for high power rating?? 3KVA????
No. They are low power devices. They can control higher power circuits with say IGBTs, etc.
New see: www.bristolwatch.com/ele3/ele6.htm Optocouplers for TTL-CMOS Logic Level Shifting
Thanks a lot! Been looking for this.
New related video OptoCoupler Interfacing H-Bridge Circuits
ruclips.net/video/Xjr7dFh3lYY/видео.html
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.
Thank you for your truly awesome and explanatory videos! Can I ask what if an IGBT is used instead of an SCR? Would this work in combination with an opto coupler controlled by Arduino/555 which would be sending the PWM signals?
No if it's DC and if AC has to phase synced.
Not sure I can answer I don't know the particular structure of the device. Just looked this up an a DC device opto-couplers will work as long as the voltage isn't too high on the opto-coupler..
www.ixys.com/documents/appnotes/ixys_igbt_basic_i.pdf
How to control speed of dc motor which is operate from 24v 10amp dc supply
@@12htech70 Make sure the drive transistor is about 15 amps.
Sir instead of tip120
Can I use tip 127
Should work.
@@LewisLoflin thanks sir it worked perfectly 👍
what is better optocoupler or mosfet ?
Not the same thing. An optocoupler is low voltage low power. A MOSFET has high voltage and current rating in most cases.
thanks. but we can have low power mosfets too ?
Yes they exist all the time within CMOS ICS, etc. The 2N7000, ZVN3306A, and the BS170 all n-channel low power MOSFETs.
I highly recommend investing in a better mic for your voice over. :)
So why noone on the internet have never built dc dc buck 100v 100A??
Maximum I ever seen is buck 55v 22A
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 ruclips.net/video/408qlS2z6ys/видео.htmlm44s, isn't a current limiting resistor required?
very good presentation thank you
thanks for the info sir
thanks dear Sir, you rescued me
how to latch circuit pls with OCP
What are you asking?
Are you asking for LASCR OCP ? If yes, then you can use it for latching circuit.
Very informative. Thanks for sharing!
Thanks appreciated and subscribed
Ich teste das
Good stuff.
thank you very much
Awesome!
👍👍👍👍👍!
Solar Charge controller
Silly, did not even mention CTR once!!!!!!!!!!
Mal sehen was wir haben
Ich sage nur wellenvormen und ich weiß was ich da mache,es ist kein Optokoppler
Tr1 und 2 tr3 naja
Elektronik ist immer in wellenvormen so das ganze Leben
Impulse
oYEEAAA send my SEMIconductor SIMULATER_eagle Autoroute_ ?? what a GUESS?? isn`t it??
Good presentation thank you
thank you sir
thank you sir