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View Full Version : BOB 3 Axis, optical isolation



thjremy
06-04-2013, 05:58 PM
http://i1157.photobucket.com/albums/p593/dangsithi/pcbb_zps9ccf8b45.png

rnr107
29-10-2013, 05:21 PM
http://i1157.photobucket.com/albums/p593/dangsithi/pcbb_zps9ccf8b45.png

Hi,
Your board looks OK... But the Photocoupler you chose are too slow. 18us for rising time and 18us for falling time... 36us total or a minimum pulse with of about 40 / 45us ... You won't be able to pulse faster than: 1/45us = 22.2KHz Mach3 pulse at 25KHz minimum...

See datasheet page 2: http://www.if.pw.edu.pl/~alice/DAC/pc847.pdf

RNR

vre
03-01-2014, 11:31 AM
Which optocouplers are suitable for high frequency servos breakout (200khz - 500khz) ?

irving2008
03-01-2014, 01:53 PM
Need more info, e.g. case style, output type, etc. but a generic 2601 is good for 1MHz or higher.

vre
03-01-2014, 07:55 PM
What you mean case style and output type ?
Because i can't find generic 2601 from these list which are suitable ?
10pcs Toshiba TLP785GB Photocoupler Optocoupler DIP-4 DIP New Original items in wellparts store on eBay! (http://stores.ebay.com/wellparts/OPTO-COUPLER-/_i.html?_fsub=9811539018&_sid=1001320378&_trksid=p4634.c0.m322)

irving2008
03-01-2014, 08:38 PM
http://www.farnell.com/datasheets/24747.pdf

tlp785 is too slow, 20kHz max. as will be most 4pin couplers

vre
05-01-2014, 01:12 PM
i mean which optocoupler from all which are in this list is suitable (not only tlp785/please go to link)
optocouplers! (http://stores.ebay.com/wellparts/OPTO-COUPLER-/_i.html?_fsub=9811539018&_sid=1001320378&_trksid=p4634.c0.m322)

irving2008
05-01-2014, 04:15 PM
i mean which optocoupler from all which are in this list is suitable (not only tlp785/please go to link)

optocouplers! (http://stores.ebay.com/wellparts/OPTO-COUPLER-/_i.html?_fsub=9811539018&_sid=1001320378&_trksid=p4634.c0.m322)

You need to do the research and read the datasheets, and if you don't know how to interpret a datasheet then you probably don't have the knowledge to use the part... but I happen to know the 6N137 (http://www.ebay.com/itm/5pcs-Everlight-6N137-EL6N137-Logic-Output-Photocoupler-Optocoupler-DIP-8-DIP-/200960463131?pt=LH_DefaultDomain_0&hash=item2eca2d511b)is an alternative for HPCL2601