Optocoupler Circuits for PLCs

A review of optocouplers in PLCs and their use with Arduino.

[@FRED82627]

Excellent tutorial about PNP/NPN sensor. Million thanks

[@Olavotemrazaodenovo]

Congratulations from Brazil.

[@tirefoto2543]

thanks once more Lewis ,learning it and sharing with my son

[@RS_83]

Thank you, Lewis. That was very interesting. Can you, please, continue making more videos on PLCs?

[@alirohollapor7521]

Thanks Lewis Ali from Iran

[@pokpikchan]

Can't thank you enough

[@johndoggett808]

Thanks for your videos, you are a good teacher. I notice that sometimes symbols for devices show a Zener Diode where I would expect a Diode. E.g. the reactive load protection diode on the PLC at 14.00 in this video. I’ve just seen a MOSFET on another of your videos where the parasitic diode was drawn as a Zener diode. Are these really Zener diodes, or is a different symbol standard being used in these diagram? Are they waring that the diodes have low reverse bias breakdown voltages?

[@_FlameXD]

Nice Explanation,Sir

[@JasonHejna]

Really informative. Thanks! Do you find that PLCs more commonly sink or source or have a combination of both?

[@yacinecool23]

thank you sir, this was very helpful...

[@tajmohammadwatandost5143]

Nice mr and thanks from information

[@jugnu361]

are these outputs from opto or a transistor is used after opto ? Thank You

[@shadmehraria5473]

Hi,Can we connect the input (IR led) of two MOC3021 in series to the output of AVR (5V) or should amplify it?Thanks.

[@Tekwyzard]

They're only LED's albeit IR ones, so just do the sum to calculate the value for the series current limiting resistor you need for 2 IR leds in series, with a forward voltage of about 1v each, at a max current of about 10ish mA. While you're at it, you could have a visible light LED in series as a status indicator too, which'll also let you know if the IR ones are conducting properly, but you'll have to factor the forward voltage of that LED into the series resistor calculation, and each colour of LED has a different forward voltage. Do not use a blue or white one, if you do, there may not be enough voltage left to properly trigger the photo triacs. You must use a series resistor for 5v or higher supply, otherwise the IR leds and maybe even the AVR output, will release the magic smoke if more than about 15 to 20 mA goes through them, AVR outputs are also better at sinking current, than sourcing it. Calculator and formula for LED series resistors here - www.digikey.co.uk/en/resources/conversion-calculators/conversion-calculator-led-series-resistor

[@irfanjalal2010]

Excellent Video ! Sir can i use 4n35 in the place of moc 3021 ?

[@LewisLoflin]

No one is a transistor the other a photo-triac/diac.

[@guillermofedericomartinez5809]

And what about with analog signals?

[@LewisLoflin]

Not made for analog.

[@wolfgangboettcher3126]

Da mach Mal den nuggel Test

[@mailonls7035]

mui beni

[@wolfgangboettcher3126]

Das finden

[@bingosunnoon9341]

Rambling and unfocused