Digital Electronics: Optocoupler | Optoisolator - Driving a high-current CREE XLamp XR-C LED

In this video I introduce and explain the operation of optocouplers / optoisolators (617A) and describe how they can be used to drive independent circuits at the same or different voltage levels. I also demonstrate that we can connect a BC547 NPN Transistor to the optocoupler and use it to drive a larger current. In this case I use a CREE XRC White 57 (XRCWHT-L1) Lumen White LED. This tutorial/experiment is part of a series of experiments that introduces digital and analogue electronics in a module EE223 at Dublin City University, Ireland. The materials are at www.eeng.dcu.ie...

[@tommyd5758]

When a CZcamsr explains everything you need for optocouplers in 20 minutes something that your University can't in 1 semester. Thank you for the awesome videos.

[@garrettherman497]

Beautifully produced and highly informative- I have been looking for an explanation for a while now; I understand. Thank you.

[@DiscoverRajivVlogs]

World best tutorial ever seen😊😊😊

[@jimadams2473]

Very good instructional video. Keep up the good work. Thanks

[@snaprollinpitts]

Excellent explanation, you know your stuff, thanks for a great tutorial!!!

[@gowtime]

Best video on optocouplers, thanks!

[@Aditya199494]

Very informative. Thanks a lot.

[@akompsupport]

This is fantastic! Thanks high quality!

[@taz0k2]

At 5:50 I don't understand where Vf comes from? Is it forward voltage of the optocoupler on the input side?
Also I don't understand where, or if, Current Transfer Ratio (CTR) comes into these calculations.

[@orenbous]

Many thanks for the great explanation.
This example shows how to protect the MCU output but how to protect the input ?
The task I am trying to solve is, how to connect 2 MCU (single pin) with cat5 wires over 20 meter distance ( low frequency 1Hz ) ?

[@theoilfield1988]

In your last circuit, what would happen if u connect the arduino directly to the bc547 transistor ??? will it work safely, not safely or not work at all ??thank you

[@edidiong1234]

Interesting video

[@heavyweather]

Around 16:15 you are talking about the current limits on the resistor. Can't you use 2 (2*Ohm) resistors in parallel to limit the current on each?

[@ahernandez2470]

shouldn't the resistor be after pin 13 before going into the diode?

[@shimesami]

Hi Derek, in the last circuit it should be ok if I put the lamp before the top right corner right? I just want to have two ports(vVCC&GND) on the board to connect different kinds of lamp later so that I can pass the 12v through the lamp & feed it to the junction. Since there will be no current through the base, I'm hopping the circuit will not make a difference

[@swvincent]

This was very helpful, thanks!

[@andrew55548]

Hello, in the schematics where the Cree cool white LED is driven i think there is something not right. You say that you drive about 80mA thru the LED using 12V power supply, and the LED forward voltage is 3.5V. With the resistance of 47ohms, the collector current when the transistor is saturated would be about 180mA. Ic=(12-3.5)/47=0.18A

[@sgtpepperaut]

that exactly what im looking for right now.... basically read car inputs (10-14V)

[@Edsdrafts]

Where in Ireland can you purchase these parts for the price he mentions?

[@yurkomik]

Thanx! Is it possible to use digital isulator for similar purpose with arduino?

[@khepraseti]

Hi ! can i use an optocoupler to an Arduino inputs(i/o) when using a 12vdc sensor?

[@ciprianwinerElectronicManiac]

awesome tutorial, thanks :D

[@Electronics61]

Thanks. great intro.

[@chrispretorius85]

Great Vid! Thanks

[@mohamedsamir3756]

thanks

[@HunS22]

LOVE YOU TY :)

[@rajdeepbarman7861]

👏

[@dahobbs9]

👍👍👍👍👍

[@sanathranjana3632]

good

[@LifeOnHoth]

Just saying... PWM is not analog in any way....