Equivalent part for D209L high voltage NPN switcher - Page 1
Forum section: electronics / repair

author: Synthetase
author_rank: Regular Contributor
timestamp: December 23, 2016, 01:34:02 am
content: Hey all, I'm trying to repair a switching power supply. The main switching transistors areD209Lhigh voltage NPN devices. One of them is dead and I need to replace it. You can get them from China, but my usual sources (RS, Element 14) don't carry them. Postage from China will take a few weeks and I'd really like to get this thing running before the end of the year. Can anyone suggest an equivalent device available at RS or E14?

author: KhronX
author_rank: Frequent Contributor
timestamp: December 23, 2016, 09:31:07 am
content: You'll probably take this as flaming or trolling, but either way, there are a few tiny problems with your advice.Not saying it's wrong, only impractical. Unlike (probably) yourself, most people don't have all that many CRT's laying around (working or not).That, and if you'll read the original post, it says "The main switching transistors are D209L high voltage NPN devices."The "transistors" and "devices" point towards there being (at least) one pair of them, so the supply's either a half-bridge or two-transistor-forward converter.With CRT's being as rare as they are nowadays, what do you think are the odds the OP might manage to find TWO identical and suitable transistors, hmm?In those sort of topologies, using two different transistors is... not exactly recommended (not to mention risky).Quote from: aquamon on December 23, 2016, 01:48:11 amOk, onto the meat of the topic...There doesn't seem to be a whole lot to choose from, but some close-enough parts do seem to be available, and for relatively low prices:http://au.element14.com/webapp/wcs/stores/servlet/Search?catalogId=15001&langId=43&storeId=10184&categoryId=800000001151&sort=P_PRICE&eq=N%3D204244%2B110007698%2B110083316%2B110115116%2B110126894%2B110137509%2B110137522%2B110148374%2B110158892%2B110169500%2B110189078%2B110197489%2B110204108%2B2101%26amp%3BNs%3DP_PRICE_FARNELL_AU%257c0%26amp%3BNtpc%3D1%26amp%3BNtpr%3D1&pageSize=25&beginIndex=1&showResults=true&aa=true&pf=110007698,110083316,110115116,110126894,110137522,110148374,110158892,110169500,110189078,110197489,110204108&vw=http://au.rs-online.com/web/c/semiconductors/discrete-semiconductors/bipolar-transistors/#esid=4294958470&applied-dimensions=4294341370,4294573563,4294573620,4294575815,4294575905,4294575986,4294576706,4294576772,4294576774&sort-by=P_breakPrice1&sort-order=ascTake your pick

author: KhronX
author_rank: Frequent Contributor
timestamp: December 23, 2016, 09:49:05 am
content: ... But the D209L is a TO3P-packaged device

author: KhronX
author_rank: Frequent Contributor
timestamp: December 23, 2016, 09:59:28 am
content: Yeah, but as in my first post, that'sassuming he has two of the same AND suitable components available just lying aroundIf he had some other mains-powered power supplies lying around, waiting to be gutted for parts, one would assume he would've told us that.But if you'll read the last sentence in the original post, it says "Can anyone suggest an equivalent device available at RS or E14?"You've done precisely that, haven't you?Quote from: aquamon on December 23, 2016, 09:52:57 am

author: george.b
author_rank: Frequent Contributor
timestamp: December 23, 2016, 10:21:50 am
content: Careful with the gain, boys. Some of the devices suggested have lower hfethan the original part.

author: KhronX
author_rank: Frequent Contributor
timestamp: December 23, 2016, 10:35:02 am
content: That's a fair point, although considering the most likely topologies, it might be quite safe to assume the designers went for "cost-effective", and as such, probably not THAT reliant on pushing component specs to the limit.... But i could be wrongQuote from: george.b on December 23, 2016, 10:21:50 am

author: wraper
author_rank: Unknown
timestamp: December 23, 2016, 01:53:21 pm
content: Quote from: aquamon on December 23, 2016, 10:36:21 amSo what? You still may run into the problems if gain is insufficient.

author: Synthetase
author_rank: Regular Contributor
timestamp: December 24, 2016, 01:48:37 am
content: Thank you all for the suggestions (and the interesting diversion..). I'm going to go through them and compare the data sheets. Will take a little while, but hopefully I'll be able to get something that'll do the job.In answer to some speculation: I don't have any old CRTs lying around, nor do I have any other old SMPS to gut. This power supply is a cheapy China special and most people would throw it away, but I'd rather have a go at fixing it because I'll learn something (even if that something is "you needn't have bothered"). It is also a half-bridge design

author: KhronX
author_rank: Frequent Contributor
timestamp: December 24, 2016, 02:25:57 am
content: I've gutted several CRT's for parts, and "even" i haven't gathered two of the same kind of beefy transistors out of them.... But i've got a whole box of ATX power supplies collected from various placesThe two-NPN half-bridge is a reasonably "classic" design, and was pretty widespread up to 500W or so (until these higher-powered and higher-efficiency double-forward converters "took over").I've had my own share of "fun" reviving an Antec SP500P that had allegedly "met" some lightning, a few years ago. If memory serves, it had a pair of 2SC3320. Still works fine to this dayI've seen 2SC2656's in several other ATX's though.Quote from: Synthetase on December 24, 2016, 01:48:37 am