Need help selecting two alternate capacitors - Page 1
Forum section: electronics / beginners

author: AtLarge
author_rank: Contributor
timestamp: November 03, 2019, 02:21:31 pm
content: I need alternates for:Xicon 1429-6223 Film Capacitors 630V .022uF 10% Tol MPPandXicon 1429-2473 Film Capacitors 250V .047uF 10% Tol MPPThe minimum order on these are 1000 pieces and 17 weeks lead time so, that's out since I am just trying to help a friend get his bike running by building him some CDI replacements.I used Mousers website and found these:Cornell Dubilier - CDE DMT6S22K-F Film Capacitors .022UF 600V 10%andVishay / BC Components BFC246753473 Film Capacitors .047uF 10% 250voltsDo these look acceptable or can anyone recommend better components that are readily available?

author: Zero999
author_rank: Super Contributor
timestamp: November 03, 2019, 08:43:29 pm
content: Please provide more information.Do they have to fit the same PCB?The CDE DMT6S22K-F has a lead spacing of 17mm vs the 10mm of the Xicon 1429-6223.The BFC246753473 is taller higher than the Xicon 1429-2473 at 14.1mm vs 10mm.Going by your post, may seem like the CDE DMT6S22K-F has a lower voltage rating than the Xicon 1429-6223 , but according to the Mouser website, it's the same DC rating, so they're probably both rated to 600VAC.https://www.mouser.co.uk/ProductDetail/Xicon/1429-6223?qs=GUzdjE0gwjaZmmIMkFulUA==https://www.mouser.co.uk/ProductDetail/Cornell-Dubilier-CDE/DMT6S22K-F?qs=nw6WWA1Y0KZtGODGMpRBVg==https://www.mouser.co.uk/ProductDetail/Xicon/1429-2473?qs=iob5vsyN1w%252Bq4Fga5HXNwQ==https://www.digikey.ee/product-detail/en/vishay-bc-components/BFC246753473/BFC246753473-ND/5369434Electrically the capacitors you've selected seem suitable, but whether they'll fit mechanically, is another matter.

author: wraper
author_rank: Unknown
timestamp: November 03, 2019, 08:51:49 pm
content: 0.022uFhttps://eu.mouser.com/ProductDetail/WIMA/MKP4J022203C00KI00?qs=sGAEpiMZZMv1cc3ydrPrF7l45uRd9dVhFng1UoSpaME%3D0.047uFmouser.com/ProductDetail/WIMA/MKP1F024703C00KI00?qs=sGAEpiMZZMv1cc3ydrPrF2CPLAojp4yWN4IXJCQeiok%3DBoth have the same lead spacing and voltage spec. Size is almost the same, some dimensions a little bit smaller so will fit fine.

author: wraper
author_rank: Unknown
timestamp: November 03, 2019, 08:55:41 pm
content: Quote from: Zero999 on November 03, 2019, 08:43:29 pmUnlikely. AC rating is usually about 40-70% of DC rating when given at all. Almost the same AC rating is very unusual. EDIT: if you look into datasheet, there is no AC rating at all. But digikey shows 250 VAChttps://www.digikey.at/product-detail/en/cornell-dubilier-electronics-cde/DMT6S22K-F/338-4501-ND/10058524.

author: floobydust
author_rank: Super Contributor
timestamp: November 03, 2019, 09:09:03 pm
content: Just sort PP film caps by lead spacing 10mm. I would substitute boxed PP film capacitors with 10mm lead spacing, i.e.EPCOS/TDK B32671L6473K000EPCOS/TDK B32671L6223K000Most are rated i.e. 630VDC and 250-280VAC. Have to see the CDI schematic if they have high pulse load or peak voltages.Mouser seems to have many typos and dud part numbers i.e. giving 222 when it should be 223 for 0.022uF

author: AtLarge
author_rank: Contributor
timestamp: November 03, 2019, 11:39:57 pm
content: I appreciate your help guys. Here's the schematic I'm working off of.I wasn't too concerned about the lead dimensions since I'll be using a hobby prototype PCB and I can adjust accordingly. It's not optimum but, we just want to get it running first so, cheap is ok and I have to build 3 of them.If they pass functional testing then I might look into having a real Gerber and boards made. These CDI boxes are terribly expensive used and NOS if you can find them is crazy money.

author: floobydust
author_rank: Super Contributor
timestamp: November 04, 2019, 04:53:54 am
content: It's worth doing a pcb design for, some new replacements going for $250-$425 ouch.I would say only the 47nF cap at the SCR gate can be a smaller low voltage part 50V. The others 3uF and 0.033uF should be 630V. Although this guy used 3uF but only 450V EPCOS, they will take 120% for short times 540V and the SCR is 600V.All-In-One CDI Unit for the H2 and H1D Price: $249 each, 5 year warrantypics attachedKawasaki Triples CDI

author: Zero999
author_rank: Super Contributor
timestamp: November 04, 2019, 07:06:23 pm
content: Quote from: wraper on November 03, 2019, 08:55:41 pmYes, there's a mistake on the Mouser website, which I failed to spot. 70% of the DC rating makes sense, as it's 1/root(2), but lower is also possible since it might not be rated for the current, which will flow due to the mains.Unfortuantely the link I posted previously didn't work. Try this one:DMT6S22K-F. It says 600VAC, 630VDC.The data sheet on Cornell Dubilier's website doesn't specify the AC voltage, but this one does and agrees with Digikey on 250VAC.http://pdf.eepw.com.cn/D20101213/d7ac661e6f17f33bcc55b421f1a03d0c.pdfQuote from: AtLarge on November 03, 2019, 11:39:57 pmYou could made footprints for the largest capacitors you can find and put additional holes to accommodate smaller components, if necessary.