WTB: high power toroidals kVA range - Page 1
Forum section: electronics / general

author: matt09
author_rank: Regular Contributor
timestamp: August 24, 2015, 02:42:41 pm
content: Looking for either two 1.6+kVA or a single 3.2+kVA toroidal transformer/s.Looking for duel 60v secondarys but I know this will be near impossible so any voltage is fine and will probablyrewind the secondary (closer the better though!)The VA specified is a minimum, so ideally that or higherCould also trade a single 2.7kVA tapped transformer.Thanks

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 24, 2015, 07:21:46 pm
content: For something that heavy you need to say whereabouts you are...

author: matt09
author_rank: Regular Contributor
timestamp: August 24, 2015, 07:23:53 pm
content: Profile updated!

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 24, 2015, 07:46:57 pm
content: Does it need to be a toroid?2x60V secondaries is very close to a centre-tapped site transformer for power tools.

author: matt09
author_rank: Regular Contributor
timestamp: August 24, 2015, 07:51:07 pm
content: I can't really accommodate the sheer size of an EI core and even the 5kVA ones are only 3kVA continuous tops.

author: ciccio
author_rank: Frequent Contributor
timestamp: August 24, 2015, 07:56:40 pm
content: I think that most custom transformer manufacturers will be happy to build a sample (if they have the necessary parts in stock).The weight is important, so I believe you should look for a British manufacturer to avoid excessive delivery costs.I can ask to my supplier (in Italy), if needed.Best regards

author: matt09
author_rank: Regular Contributor
timestamp: August 24, 2015, 07:58:53 pm
content: I know of some companies who will do a custom wind but it is going to cost a fortune in copper alone..Used definitely seems the way to go.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 24, 2015, 11:55:21 pm
content: If weight is more critical than other aspects, consider a switching supply. It can still have AC output, if not necessarily at the expected frequency (higher frequencies being your prime advantage).Tim

author: matt09
author_rank: Regular Contributor
timestamp: August 26, 2015, 09:05:30 am
content: Weight and price are equal, switching supplies in this power range / voltage cost a fortune.Would also consider 3kVA.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 26, 2015, 09:29:35 am
content: Quote from: matt09 on August 26, 2015, 09:05:30 amDefine fortune - Meanwell do 1500w PSUs for about £220 - a couple in series gets you 3kw for under £500By the time you've added rectifiers & caps, and dealt with inrush issues a toroid may work out more expensive.For a 1-off, keep a lookout for surplus telecom PSUs which are typically in the 48-60V range

author: nctnico
author_rank: Super Contributor
timestamp: August 26, 2015, 09:46:53 am
content: I agree with Mike here. Switching PSUs have become very affordable and if you need a limited number of supplies then Ebay is very likely to provide what you need. In most cases you can adjust the output voltage as well. A 48V telecom power supply is usually set to 56V so it is already very close to what you require.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 26, 2015, 11:15:59 am
content: Also, telecom PSUs are sometimes called rectifiers, which may lead to ebay bargains due to people not knowing what they aree.g. here are a couple of 1.3kw PSUs going cheap :http://www.ebay.co.uk/itm/POWER-ONE-PMP-13-48-Sic-Rectifier-/221838456239?hash=item33a69a35afhttp://www.ebay.co.uk/itm/HARMER-and-SIMMONS-SM1800-RECTIFIER-/141739087960?hash=item21004ed858Telecom PSUs are usually extremely good quality, built for 24/7 operation at full load, and with very low noise.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 26, 2015, 11:22:43 am
content: And another - 48V 25A for £115http://www.ebay.co.uk/itm/NORTEL-HELIOS-RECTIFIER-NT5C06DB-/191650132266?hash=item2c9f3cf12a

author: poorchava
author_rank: Super Contributor
timestamp: August 26, 2015, 01:43:18 pm
content: You could check toroidy.pl I think their price for custom 3.5kVA transformer (including vat and shipponh) would be in the order of 200Euro.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: August 26, 2015, 02:46:06 pm
content: 56v 28A for £45, 5 availablehttp://www.ebay.co.uk/itm/INVENSYS-RECTIFIER-MODULE-R160-54-28A-WARRANTY-/181687855576?hash=item2a4d70a9d8

author: matt09
author_rank: Regular Contributor
timestamp: August 27, 2015, 10:58:51 am
content: Thanks for the suggestions and some of those ebay telecom units are a good price.However I already have a bunch of huge electrolytics and many other parts for free from various places the project as well as enclosure that wouldn't really fit those units. It's for a high power high quality linear amplifier so I'd prefer to go with an old school power supply. 2+ of those units would take up more space than a Toroid for the same output while weight isn't really an issue. Additionally I'd have thermal concerns with reboxing those units at high power.ciccio that sounds too cheap to be true, are you sure about that price of 200 euro?? I assume you mean for local shipping within Poland?

author: ciccio
author_rank: Frequent Contributor
timestamp: August 28, 2015, 07:03:47 am
content: Sorry, but I did not write any quote.It was another poster (poorchava) from Poland that wrote 200 euros from a company whose site (toroid.pl) is not accessible (a spelling error?).My supplier is surely higher.International delivery can be very expensive, due to weight.Other posters wrote about switch-on current peaks: in my experience this is a real problem.A 3 kVA toroid can surely trip a standard 16A circuit breaker when switched on. You need to design a current limiting circuit.Best regards

author: poorchava
author_rank: Super Contributor
timestamp: August 30, 2015, 10:09:21 am
content: The address is toroidy.pl IIRC they do have a website version in English, but I don't know how it is with shipping abroad.Wys?ane z mojego HTC One M8s przy u?yciu Tapatalka

author: matt09
author_rank: Regular Contributor
timestamp: October 01, 2015, 09:35:30 am
content: bump for search

author: Deathwish
author_rank: Unknown
timestamp: October 01, 2015, 10:01:39 am
content: Quote from: poorchava on August 30, 2015, 10:09:21 amhttp://sklep.toroidy.pl/