controlling a hotwire

[Demon]

I use the MCT6 opto-coupler a lot in 5vdc circuits.

Resistor is easy, 330R like most LED.


Very interesting read here on optos:
http://www.jaycar.com.au/images_uploaded/optocoup.pdf

Didn't know about using a reverse diode on input side as added protection, nice:

...
In some circuits, there may be a chance that at times the driving voltage fed to the input LED could have reversed polarity (due to a swapped cable connection, for example).

This can cause damage to the device, because optocoupler LEDs tend to have quite a low reverse voltage rating: typically only 3 - 5V. So if this is a possibility, a reversed polarity diode should be connected directly across the LED...

[mister_e]

There's opto with dual LED inside as well.

[Demon]

There's opto with dual LED inside as well.

Exactly, that's why I like the MCT6.


Now if you want to go quad:
http://parts.digikey.com/ca/1/140440...pct4216-a.html

[Demon]

Bert, any chance of pics of the machine?

[cncmachineguy]

I will see what I can do. I'm not sure I have any right this second that will do it justice.

[cncmachineguy]

Heres a pic. If you look close, you can see the wire. It is connected to the black arm on the left side of the pic.


Not sure why I can't make the pic show up without clicking the link. Hmmm

[mister_e]