Silicon Chip Power Supply - Page 1
Forum section: electronics / beginners

author: C-47
author_rank: Regular Contributor
timestamp: March 16, 2022, 09:58:07 am
content: Hi, newbie question. I'm trying to finish off the above power supply I started some 20+ years ago, but in the interim I have lost the 2 power MOSFET's BUK436-200A which are 19A - 200V. The usual local suppliers have been of little help in finding / recommending replacement item, hence the call out.I do see these available in the USA but shipping ect makes it a non goer. Thanks for any advise / leads. Alan.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: March 16, 2022, 03:58:55 pm
content: Hi, Alan. Welcome aboard.I'm probably not much help since I could only get the same search results as you did, but can you tell us which power supply or magazine edition in case someone might like to help select a substitute part.

author: Terry Bites
author_rank: Super Contributor
timestamp: March 16, 2022, 05:00:36 pm
content: https://nz.element14.com/w/c/semiconductors-discretes/fets/single-mosfets?continuous-drain-current-id=20a|21.5a|25a|26a|28a|30a|31a|32a|32.7a|37a|39a|50a|56a|65a|78.5a|90a|100a|120a|140a|150a&drain-source-voltage-vds=200v&range=inc-in-stock&sort=P_PRICE

author: C-47
author_rank: Regular Contributor
timestamp: March 16, 2022, 08:09:51 pm
content: Ed, the power supply is 40V 8A published in Silicon Chip April - May 1998, a revised / updated version was published, Oct - Nov - Dec 2019 also in SC. A bit of an ancient project in electronic terms, but retirement has provided the opportunity to hopefully complete.Terry, thanks, the link provided is a winner by the look of it and stock is listed, much appreciate your help. Alan.

author: C-47
author_rank: Regular Contributor
timestamp: March 18, 2022, 08:37:53 am
content: Have ordered the Mosfets per Terry's lead, thanks, should be here in a week or so, I hope so I can get with it.The question I have, has anyone on the forum, probably in Oz, completed the kit and have it working, as I understand there were a certain number of improvement mods over time of which I have no info on. Thanks, Alan.

author: lowimpedance
author_rank: Super Contributor
timestamp: March 18, 2022, 11:08:45 am
content: Have you tried emailing Silicon Chip and asking them if 'errata', improvements for this project exist.I would be surprised if they don't, perhaps they will email you a copy for free.

author: C-47
author_rank: Regular Contributor
timestamp: March 19, 2022, 02:29:55 am
content: Thanks, I'll give them a try next week.

author: wilfred
author_rank: Super Contributor
timestamp: March 19, 2022, 04:56:50 am
content: Errata is available on the Silicon Chip Website. 1998 is herehttps://www.siliconchip.com.au/Articles/Errata/2595/4627It is under the Articles pulldown by year.

author: C-47
author_rank: Regular Contributor
timestamp: March 19, 2022, 08:44:09 am
content: Thanks to all, I've had a bit of a scrounge on the SC website and see nothing pertaining to the 1998 version of the power supply, however have sent their Tech dept a query just in case I've missed something. Alan.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: March 19, 2022, 08:55:45 am
content: Quote from: C-47 on March 19, 2022, 08:44:09 amI noticed that too. Maybe the design was just purrrfect!hahahahaha.

author: wilfred
author_rank: Super Contributor
timestamp: March 20, 2022, 03:09:38 am
content: Quote from: C-47 on March 19, 2022, 08:44:09 amThey'll probably go to the same place.If there was a mistake or design flaw there'll be errata for it. But if they offer an updated design years later then that is probably for component availability reasons or there is a cheaper way to do it for a popular kit and likes of DSE, Jaycar et al suggested or requested it. But that didn't happen often.I think in the case of this power supply they tried a switch-mode version.For old projects offered as a kit you could always see if the supplier has old stock still tucked away. It's unlikely but you don't want to die wondering. I've got PDF's of old kits emailed to me a couple of times. It's not a component but they're not unhelpful in my experience.It is always worth trying Rockby.com.au as they have old stock bought from shops around Melbourne that closed down. eg Rod Irving, TECs and Truscotts. They didn't have this component you wanted though. I looked.If they got all of Truscott's components then they have stuff they haven't catalogued yet. They closed the clearance room pre-Covid and who knows when it will re-open. If ever.

author: C-47
author_rank: Regular Contributor
timestamp: March 20, 2022, 07:18:27 am
content: Thanks, I got a reply from SC who reckon there were no revisions / errata for the one I have on their records, it was the 1992 year that had such, so maybe like Ed reckons its puuurfect! but with my construction abilities I'm sure that will be tested. While there is a 2019 version of the same basic design which I looked at, but at around $350 just for components its hard to justify when there are so many off the shelf ones around, maybe not the same quality though. however I'd like to complete the one I have. Alan.

author: not1xor1
author_rank: Frequent Contributor
timestamp: March 20, 2022, 08:16:27 am
content: Quote from: C-47 on March 20, 2022, 07:18:27 am350 $ (Australian) ? That should be a little less than 240€... How can be that expensive? Could you post a picture of the schematic ?

author: C-47
author_rank: Regular Contributor
timestamp: March 20, 2022, 10:07:48 am
content: Hi not1xor1,Europe has many more options I feel than here in Oz which is the end of the supply train line, so expensive for everything, NZ is worse.Before the current travel situation, a quick holiday to Asia would be a worthwhile event as things so much less expensive than here, but what to do.Just as a rough idea of pricing for some items: transformer $110, case $80, pcb $20, some hard to find parts kit $45, display complete IIRC $60 and then keep going for all the other bits and pieces if you don't have on hand, so that was my rough estimate. Sorry I don't have the schematic, but some other photos attached. Alan.

author: not1xor1
author_rank: Frequent Contributor
timestamp: March 21, 2022, 08:18:24 am
content: Quote from: C-47 on March 20, 2022, 10:07:48 amthanks for the pictures, but that's crazy... 45V 8A and a single winding transformer... no multitap switching... no preregulator... just a lot of energy waste...it would be comfortable when it is cold