need sugestion for opto coupler

[xinzc28]

I'm planning to make parallel interface board with opto isolation.
I got a schematic using HCPL2630 chip, but the chip is unavailable at my place.

I'm newbie on electro, so I'm not really understand the info that datasheet provide.

I have some PC817, but some says it slow?
can somebody give me some model that fast enough? 1 or more opto on one chip is fine with me, since I can modify the schematic.

[keebler303]

Most use a 4n25 for logic I/O.

If you are going to be driving relays or similar, you might think about AQV252. Its quite pricey but they are nice and easy to use for driving relay coils reliably.

Matt

[irving2008]

Originally Posted by xinzc28 I'm planning to make parallel interface board with opto isolation. I got a schematic using HCPL2630 chip, but the chip is unavailable at my place. I'm newbie on electro, so I'm not really understand the info that datasheet provide. I have some PC817, but some says it slow? can somebody give me some model that fast enough? 1 or more opto on one chip is fine with me, since I can modify the schematic.

Compared to the 2630 the PC817 is very slow, the minimum pulse width will be about 40uS worst case (although the average part might be only 10uS) - a 2630 is about 400 times faster at 100nS pulse width. To put this into context, a 40uS pulse is equivalent to 2500steps/sec or 750rpm on a 1.8deg stepper - this may be sufficient for a low speed machine however all the good quality opto-isolating BOBs I have seen use the 2630 for the output channels and something like the PC817 for the input channels (which can be a lot slower)..

There are very few opto devices that are equivalent to the HCPL2630, however I don't understand why you are having difficulty getting them... Farnell Singapore (http://sg.farmell.com) have 46 Fairchild devices in stock in Singapore at S$3.64each

[epineh]

I use 2630's for step/dir signals and pc817 for limit/estop

If you can't get 2630's try getting 6N137 this is a single channel version of the 2630, I can get the 6N137 easily in Australia but the 2630's I need to get from the US, I use Digikey for these, they are great to deal with, and ship straight away.

Good luck !

Russell.

[xinzc28]

thanks for your info.

I search the net for some alternative optos that you all mentioned, and found these: Fairchild H11L1M, 74OL6000. can it be use for isolating parallel port?

especially H11L1M, if it can be use, maybe I can eliminate 74HC14N chip on driver board?

[neilw20]

Leave the 74HC14N chip where (ever) it is.
It has schmitt trigger inputs, and will help with noise immunity.

[xinzc28]

as mentioned before, i newbie to electronic. which one is best for isolating parallel port and interfacing the stepper drive? (the optocoupler in the circuit is just sample)
I hope you can give me some explanation about these circuit..for my knowledge