Finding spec sheets for some old Optocouplers is getting harder :( - Page 1
Forum section: electronics / general

author: casinada
author_rank: Frequent Contributor
timestamp: April 03, 2014, 05:48:59 am
content: I'm trying to repair a Fluke 5100 Calibrator, it has some optocouplers that are not longer manufactured, the parts in question are:8501M by Clairex Electronics and Q1813 by Monsanto.Monsanto was pioneer in the Semiconductor wafer and LED field but is long gone:History of Fairchild’s Optoelectronics Group1969: Part of Monsanto Electronic Materials Group1979: Acquired by General Instrument CorporationAcquired Fairchild Semiconductor’s Optoelectronics Group1990: Acquired by Recovery Equity Investor’s, L.P.1990: Initially named Quality Technologies1991: Acquired Harris Semiconductor Optoelectronics Division1992: Acquired Philips Semiconductor Optoelectronics Business1995: Changed name to QT Optoelectronics1998: Acquired Motorola Semiconductor Optocoupler Business2000: Acquired by Fairchild Semiconductor2001: Becomes Optoelectronics Group of Fairchild SemiconductorThe Monsanto part seems to be a 4N28 as newer Fluke schematics show that part.The Clairex part is the one I can't find equivalent. This is part of the schematic:U103 and U107 are the Clairex part and are also a matched set. U108 and U109 can be replaced with 4N28 Optocouplers.I don't know if those parts were specifically designed for Fluke. Back in those days some audio equipment was designed using similar parts according to some old application notes I found on the web.

author: David Hess
author_rank: Super Contributor
timestamp: April 03, 2014, 09:21:00 am
content: My guess is that the optocoupler is CdS based and that technology is deprecated because of ROHS concerns.The H11F1/H11F2/H11F3 series of FET optocouplers might work as acceptable substitutes.

author: wraper
author_rank: Unknown
timestamp: April 03, 2014, 10:12:38 am
content: My guess is that one of those would fit (different specs). I would measure led current/output resistance dependence of the one working old part. Then select nearest substitute.http://uk.farnell.com/jsp/search/browse.jsp;jsessionid=1MLCVMMRG5ZIGCQLCIPZMMQ?N=0&Ntk=gensearch&Ntt=RESISTIVE+O%2FP&Ntx=mode+matchallpartial&exposeLevel2Refinement=true&suggestions=false&ref=globalsearch&_requestid=98299

author: David Hess
author_rank: Super Contributor
timestamp: April 03, 2014, 11:18:54 am
content: Maybe the 5 in the part number was really a 6. Clairex lists the CL8601M as a discontinued part with the specifications of Ron=4k and Roff=10Meg. I was not able to find a datasheet.

author: Stonent
author_rank: Super Contributor
timestamp: April 03, 2014, 12:54:36 pm
content: Mmmm GMO....Genetically Modified Optocoupler.....

author: casinada
author_rank: Frequent Contributor
timestamp: April 03, 2014, 09:52:24 pm
content: The parts list in the manual was a little bit cryptic, I don't know if is a typo. I couldn't find a part in the Clairex site with similar symbol.U103 is listed as CL, /8501MJust took a picture of the part, it is definitely a CL8504M.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: April 04, 2014, 01:34:43 am
content: You could make your own from a CdS photocell and LED (green or red), heat-shrinked together. I hope there's some way to calibrate those though.Tim

author: casinada
author_rank: Frequent Contributor
timestamp: April 04, 2014, 03:44:41 am
content: That is a possibility. I think the Optocouplers on the boards work. I started looking for the parts as I like to do when I do circuit debugging and found the manufacturers no longer exist. One of the posters suggested a similar part that is used in audio equipment and guess what, Silonex, the manufacturer has been absorbed by Advanced Photonics and the spec sheet for the part is not on the new sitehttp://www.alliedelec.com/images/products/datasheets/bm/SILONEX_INC/70136794.pdfTry to go towww.silonex.comand see what happensThe parts are still in stock and sold by a few distributors:http://www.findchips.com/search/nsl-32