Isolation Transformer Recommendations - Page 1
Forum section: electronics / general

author: johnny diaz
author_rank: Contributor
timestamp: March 05, 2013, 02:47:34 pm
content: So I'm looking to get an isolation transformer for light to mid duty. Any recommendations?

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: March 05, 2013, 03:23:02 pm
content: one option is to find 2 identical mains transformers and connect the low-voltage sides to each other.

author: johnny diaz
author_rank: Contributor
timestamp: March 05, 2013, 05:38:42 pm
content: Thanks but I would prefer to just buy one.

author: mariush
author_rank: Super Contributor
timestamp: March 05, 2013, 05:44:58 pm
content: You've asked this question on another forum and you got answers there as well.What answer do you really expect to receive?Just go on digikey or newark/farnell.com/element14 or mouser or rs-components at the isolation transformers section and pick one, as big as you can afford it, or as big as you think you're gonna need one.An isolation transformer is just a fancy transformer, usually more expensive at retail. You may soon find out two normal, identical transformers are cheaper than a single "isolation transformer".

author: johnny diaz
author_rank: Contributor
timestamp: March 05, 2013, 06:35:44 pm
content: What I'm looking for is someone who can recommend a good quality isolation transformer which I can buy ready made. I'm willing to spend up to $500 for it. I would like one which is rated up to 1000 watts. Company's like tripp lite, sencore and olympus to name a few. I don't have any experience with any of these brands.

author: StubbornGreek
author_rank: Frequent Contributor
timestamp: March 05, 2013, 07:24:48 pm
content: Try scouring ebay for good iso's. Stay away from the medical isolation transformers as those don't provide true isolation without a bit of modification (Triplite's are mostly medical grade).

author: johnny diaz
author_rank: Contributor
timestamp: March 05, 2013, 07:47:03 pm
content: There is a video on youtube regarding the tripp lite is1000hg where the user recommends disconnect one cable. Is this the mod your referring to?

author: AndyC_772
author_rank: Super Contributor
timestamp: March 05, 2013, 08:39:51 pm
content: http://www.conrad-uk.com/ce/en/Search.html?search=1000va

author: mzzj
author_rank: Super Contributor
timestamp: March 05, 2013, 08:46:37 pm
content: here is somehttp://www.surplussales.com/transformers/IsolationXmers-2.htmlI would stick with brand name products, bought some isolation transformers from amazon and those were utter crap.

author: r90s
author_rank: Regular Contributor
timestamp: March 06, 2013, 08:27:11 pm
content: Quote from: johnny diaz on March 05, 2013, 07:47:03 pmI also recommend That unit or one of the other sizes of the isolation boxes. I have used many of their products, including UPS units of their's that were very reliable commercial units. They make many of these for hospitals. And yes it's a one wire mod....

author: KD0CAC John
author_rank: Frequent Contributor
timestamp: March 06, 2013, 08:50:49 pm
content: Where are you located ?I see a lot of them around , have sold a bunch of the Topaz units like in the link above , also most never more than around $150 .

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: March 06, 2013, 10:11:07 pm
content: I'm in Australia, I just bought a 600W 230V isolation transformer the other day for $200 delivered.Tortech is the name of the company, I have used their gear before, it's what you need and nothing more, they have been doing it for years and I trust them.So I gave them my money.

author: smashedProton
author_rank: Frequent Contributor
timestamp: March 08, 2013, 06:24:54 am
content: Can't you just get a rheostat and leave it on 1:1? It would be multi use

author: Psi
author_rank: Super Contributor
timestamp: March 08, 2013, 06:48:36 am
content: Quote from: smashedProton on March 08, 2013, 06:24:54 amIn what way is that isolating?A rheostat set so Vout = Vin would be a direct connection

author: smashedProton
author_rank: Frequent Contributor
timestamp: March 08, 2013, 08:06:54 pm
content: Variac

author: Monkeh
author_rank: Super Contributor
timestamp: March 09, 2013, 01:10:44 am
content: Quote from: smashedProton on March 08, 2013, 08:06:54 pmVariac does not equal isolation transformer.

author: NiHaoMike
author_rank: Super Contributor
timestamp: March 09, 2013, 03:06:29 am
content: Most variacs are not isolated.You can also try running a power inverter from a PC power supply, although many (most?) inverters are not isolated. But it's pretty easy to modify a PC power supply to be isolated. Or you can use a supply that is already isolated like a large bench supply or a battery.

author: ddavidebor
author_rank: Super Contributor
timestamp: March 09, 2013, 06:16:36 am
content: Whyyyyy?Take 2 12v trasformers and wire one in the opposite way...

author: Unknown
author_rank: Unknown
timestamp: March 09, 2013, 03:20:01 pm
content: Quote from: NiHaoMike on March 09, 2013, 03:06:29 amIt's easy to cut the connection between safety ground and the negative output rail, but making sure it still meets safety and EMI/EMC requirements may not be so easy.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: March 09, 2013, 11:37:37 pm
content: QuoteI thinks it's a joke but it would basically work, it could be used as a kludge for if you don't have an isolation transformer handy.You wouldn't use it anywhere except in your lab, as your voltage would be down due to a double lot of voltage regulation.But look on the bright side, your fault current would be very low.

author: nukie
author_rank: Frequent Contributor
timestamp: March 10, 2013, 12:57:17 am
content: What happens to the AC output when you double transformer? This is interesting please explain.

author: c4757p
author_rank: Super Contributor
timestamp: March 10, 2013, 01:03:13 am
content: Quote from: ddavidebor on March 09, 2013, 06:16:36 amIf you're going to use two transformers connected together, you should probably use a higher voltage to minimize voltage drop between them. 48V transformers are reasonably common.