230V to 110V conversor - Page 1
Forum section: electronics / beginners

author: Nuno_pt
author_rank: Frequent Contributor
timestamp: June 07, 2016, 02:00:52 pm
content: Hi all,I need one conversor for converting 230V to 110/115V for some stuff that I got here, the requirements are 50W.I saw this on epay would they get the job done.http://www.ebay.com/itm/New-110V-to-220V-STEP-Up-Down-VOLTAGE-CONVERTER-100W-Watt-TRANSFORMER-TRAVEL-/301729430585

author: Karlo_Moharic
author_rank: Regular Contributor
timestamp: June 07, 2016, 02:02:27 pm
content: What exactly do you need it for ?

author: Nuno_pt
author_rank: Frequent Contributor
timestamp: June 07, 2016, 02:06:22 pm
content: To convert the 230V to 110V to an PSU that I got here.Nothing fancy.The PSU is rated at 30W so 100W conversor should do it.

author: Nuno_pt
author_rank: Frequent Contributor
timestamp: June 07, 2016, 06:48:39 pm
content: Will this work ok or is not possible.

author: Zermalmer
author_rank: Regular Contributor
timestamp: June 07, 2016, 07:47:17 pm
content: From the description...I would work I think, but you maybe need a plug converter for input side.BUT I'm not sure how save it is for continues use for a longer time.

author: MK14
author_rank: Super Contributor
timestamp: June 07, 2016, 07:55:58 pm
content: Is it a proper "switching/SMPS" one and/or transformer one ?Or is it "cheating" and using SCR/Triacs in a light dimmer kind of configuration ?(Which would only be suitable for resistive loads, such as lamps, hair driers etc).Which would potentially break your power supply, as it would still intermittently give the full voltage.I CAN'T tell either way, from the description, but would be careful.

author: Ian.M
author_rank: Super Contributor
timestamp: June 07, 2016, 08:21:07 pm
content: The switchable wallwart ones on EBAY like the one above are almost always dodgy.Google search keywords for a good one: EBAY Autotransformer 230V 115VAlso try searching with 220V 110V, and 240V 120V, to catch more listings.Often, the moderate power ones have two metal end shells bolted directly to the transformer core covering the windings, usually with a USA socket panel mounted through one shell.If its a true autotransformer, it doesn't matter if its intended for step-up (115V in 230V out) as they can easily be rewired for step-down.

author: Nuno_pt
author_rank: Frequent Contributor
timestamp: June 07, 2016, 08:59:28 pm
content: Thanks Ian.M.I found this one from UK, it should do it, maybe.http://www.ebay.co.uk/itm/300W-UK-to-US-Stepdown-Voltage-Converter-Transformer-240v-to-110v-USA-/271337313082?hash=item3f2cf6d33a:g:SaMAAMXQ4uJSGGr8It's 300W rated, the lead plug is from UK, but I can put in one from EU.My idea is to plug one converter on the 230V plug, and on the 110V output, plug in one strip with 4 or 5 US 110V plugs, to connect the PSU(s).The PSU itself uses 30W, so 300W should be ok for 8 PSU at the same time, if the converter is good.Is my thinking correct?

author: ovnr
author_rank: Frequent Contributor
timestamp: June 08, 2016, 01:04:58 am
content: Yes, your thinking is correct.Have you considered replacing the power supplies instead? If they're plugpacks or otherwise not integrated into equipment, that seems like a better idea.

author: Brumby
author_rank: Unknown
timestamp: June 08, 2016, 01:33:24 am
content: I put together four 60VA 30V multi-tap transformers for a 240V - 110V step down (because I had them on the shelf) to power a guitar amplifier imported from the USA. After a bit of searching, I found a toroidal with the correct windings for a direct replacement of the main transformer of the amp. Upgraded the mains cap, checked the power switch specs and changed the fuse. Whole upgrade for about $100.If the transformer in the unit doesn't have a 240V primary tap you could swap to, then sometimes replacement is a viable option. Neater, too.PS. I had contacted the US manufacturer for specifications, so I could select the appropriate transformer - but they said the alteration could not be done.Yeah.... well.... After a couple of measurements and load considerations, I had some workable numbers.

author: helius
author_rank: Super Contributor
timestamp: June 08, 2016, 03:29:38 am
content: Many devices, including bench equipment, have so-called 'universal' transformers. They have two primary windings that can be connected in series (for 240 V) or parallel (for 120 V), even if there is no exterior voltage switch. So conversion is then very easy as long as the phase dots are followed.Real voltage conversion transformers or autotransformers are quite heavy, a 1000VA converter could weigh 20 kg. So shipping costs will be very high. If they aren't then it's a crappy chopper unit that won't have sine wave output.

author: Nuno_pt
author_rank: Frequent Contributor
timestamp: June 08, 2016, 08:57:11 am
content: The conversion on the PSU itself is only possible when replacing the trafo, Dave already try to do the mod on the PSU itself.The trafo is solder directly to the board, and the mains enter directly to the ON/OFF switch, then back to the trafo, so the only way is to replace the trafo.Low cost solution here was an converter from 230V to 110/115V, the PSU only need 30W.

author: Audioguru
author_rank: Super Contributor
timestamp: June 08, 2016, 11:34:03 am
content: The cheap ebay Chinese transformer is not tested and certified to be safe. If it causes your home to burn down and it is found as the cause then the insurance will not pay.

author: Nuno_pt
author_rank: Frequent Contributor
timestamp: June 08, 2016, 01:07:33 pm
content: Audioguru,The question here is not if it will cause fire or the insurance doesn't pay.The question here is if the second conversor can be use to power one/some PSU(s) of 30W each.My first guess is that one conversor like the second link is use with an rated output of 300W, it should be safe to power 3 to 7 PSU(s), 3x30W=90W or 7x30W=210W, so the margin should be safe.

author: nanofrog
author_rank: Super Contributor
timestamp: June 08, 2016, 01:40:31 pm
content: Quote from: Nuno_pt on June 08, 2016, 01:07:33 pmThe type you found the second time would be the way to go.FWIW, I've seen such units swap W for VA ratings, so you might want to take that into consideration as well in your total power calculations.

author: jitter
author_rank: Frequent Contributor
timestamp: June 13, 2016, 06:28:19 pm
content: Yeah, the first one might not be so good: