Identifying a power FET from faulty SSR - Page 1
Forum section: electronics / beginners

author: anvoice
author_rank: Frequent Contributor
timestamp: April 17, 2015, 11:05:41 pm
content: Hello,Got a couple of SSRs off of ebay recently, since it was the only place I could find DC SSRs. Fotek, rated for 40A, undoubtedly counterfeit, but I took a chance on it being a quality clone. However, they arrived in extremely poor packaging and one was quite banged up. I tested the other and it burned out in seconds while switching 15A (rated 40) despite being hooked up to a properly sized heat sink.The seller is offering a replacement. Naturally I wouldn't ever use those without thoroughly testing them first, but I was wondering if it's even worth giving it another try. Thus I took one apart and uncovered the power FET to check its rating, but I can't find anything of the sort online.It says NEC on the first line, 412 on the second, and the part number on the third line is A1009. Does anyone have any idea what this FET is and where I could get a data sheet?If anyone has any links to good instructables for DIY DC relays, I'd appreciate seeing those. Thanks!

author: wraper
author_rank: Unknown
timestamp: April 17, 2015, 11:21:14 pm
content: According to the marking this should be 2SA1009 PNP transistor. However this is strange, SSRs usually are triac based.

author: tautech
author_rank: Super Contributor
timestamp: April 17, 2015, 11:33:53 pm
content: Bit of a hunt but it seems to be: 2SJ412, TO-220, P Ch 100V 16A

author: anvoice
author_rank: Frequent Contributor
timestamp: April 18, 2015, 01:14:06 am
content: Quote from: wraper on April 17, 2015, 11:21:14 pmIf that's it, it's rated at 2A I believe... Pretty unbelievable to use it in a 40A SSR. I believe AC control SSRs are triac based, while DC ones are power FET-based.Quote from: tautech on April 17, 2015, 11:33:53 pmOut of curiosity, what on the markings implies that? That would be better than the 2SA1009, but still well under the rating.

author: amyk
author_rank: Super Contributor
timestamp: April 18, 2015, 02:02:32 am
content: 2SJ412s don't come in that package.This is most likely 2SA1009, maybe even a fake version of it as some of them have the "A1009" on the middle row and some on the bottom:http://www.taobao.com/product/2sa1009.htmlhttp://item.taobao.com/item.htm?id=44824285937

author: anvoice
author_rank: Frequent Contributor
timestamp: April 18, 2015, 02:13:37 am
content: Quote from: amyk on April 18, 2015, 02:02:32 amThe one in the second link looks identical to mine. I can't find its characteristics since the page is all in Chinese, but the title seems to imply it's supposed to be an equivalent to the 2SA1009. So the verdict is they used a FET rated for 2A in a 40A SSR? I think refund it is.Thanks for the help.

author: Mechatrommer
author_rank: Super Contributor
timestamp: April 18, 2015, 05:19:35 am
content: 2SA1009... 2A rating PNP...http://www.datasheetcatalog.com/datasheets_pdf/2/S/A/1/2SA1009.shtml

author: anvoice
author_rank: Frequent Contributor
timestamp: April 18, 2015, 05:25:21 am
content: Quote from: Mechatrommer on April 18, 2015, 05:19:35 amRight, so it's underrated... A lot.

author: Mechatrommer
author_rank: Super Contributor
timestamp: April 18, 2015, 05:30:21 am
content: Quote from: anvoice on April 18, 2015, 05:25:21 amits not underrated. you have been scammed.

author: anvoice
author_rank: Frequent Contributor
timestamp: April 18, 2015, 05:51:32 am
content: Right, I'd still call marking a 2A SSR as 40A as "overrating" it, and the 2A SSR is thus and underrated component given the label. That it was probably done knowingly indeed makes it a scam.

author: Mechatrommer
author_rank: Super Contributor
timestamp: April 18, 2015, 12:09:37 pm
content: as others mentioned... PNP transistor is not SSR, when its an SSR, it will be mentioned in datasheet as SSR, not PNP. 2ndly overrating a device by stating it as 20X more powerful is an obvious scam. but if you are happy with it, then fine. ymmv.

author: anvoice
author_rank: Frequent Contributor
timestamp: April 18, 2015, 10:02:39 pm
content: The device itself was an SSR: I had to take it apart to get the FET (which is a part of an SSR).Not sure how you came to the conclusion that I was happy with it. I was merely getting straight the facts: the SSR is under specs. Thus, I'm getting a refund.Thanks for the help.

author: jeff.remus
author_rank: Contributor
timestamp: April 19, 2015, 05:30:23 am
content: A 40N60 should do the trickhttps://www.google.com/search?q=40n60+fet&ie=utf-8&oe=utf-8#q=40n60+fet&tbm=shop

author: Mechatrommer
author_rank: Super Contributor
timestamp: April 19, 2015, 07:20:32 am
content: Quote from: anvoice on April 18, 2015, 10:02:39 pmhuh? you can dismantle an SSR to get a PNP inside? well thats new! i thought SSR is "solid" like this...and you keep talking about "FET" but what you showed is PNP. PNP is not FET, so i guess the main driver is the "FET", usually FET is more powerfull than PNP, so i guess the 2A PNP you showed is for driving the FET gate, well, thats an overated 2A gate driving PNP, thats quality! i think its a good idea to post the whole picture.