Noob question - running a 240V device on 120V

[johnsonic]

Hi!

Wondering if someone can point me in the right direction here - I have a 240V euro device on the way and need to run it on my wall power (120V). Is there anything more to it than grabbing a step up / down box on amazon and call it a day? Can anyone point me to a device they like?

Have already confirmed that voltage is not switchable on the unit.

Thank you!

 

[JohnRoberts]

Different kinds of units may be easier or harder.

In general a simple 1:2 voltage step up transformer could work. Domestic 60 Hz is easier than 50 Hz for internal transformers and power supplies.

JR

 

[2nickel]

You don't tell us what the "device" is. 240V devices often require 50Hz whereas 120V electronics in North America use 60Hz. E

 

[johnsonic]

It's a tape locator - the schematics show the same components in the power supply for all regions, aside from the transformer so pretty sure cycle frequency won't be an issue.

 

[Electrobumps]

Hi!

Wondering if someone can point me in the right direction here - I have a 240V euro device on the way and need to run it on my wall power (120V). Is there anything more to it than grabbing a step up / down box on amazon and call it a day? Can anyone point me to a device they like?

Have already confirmed that voltage is not switchable on the unit.

Thank you!

I'm someone who has moved from the UK to the USA with all my gear and I didn't any issues with 50-60hz, but always worth checking. The equipment I wasn't able to switch externally I could rewire internally. Apart from a few pieces that did not have the windings on the PTX to do it. I would check if you can rewire the PTX for 120v before buying an external TX.

Also to note most houses in the USA have 240v it just depends if it is practical to access it.

 

[JohnRoberts]

I'm someone who has moved from the UK to the USA with all my gear and I didn't any issues with 50-60hz, but always worth checking. The equipment I wasn't able to switch externally I could rewire internally. Apart from a few pieces that did not have the windings on the PTX to do it. I would check if you can rewire the PTX for 120v before buying an external TX.

Also to note most houses in the USA have 240v it just depends if it is practical to access it.

This is less of an issue with modern gear. Back a few decades ago when I was still in the ditches manufacturing SKUs to sell internationally we often had to manufacture unique SKU for each country. For years the UK was 240VAC 50Hz while most of Europe was 220VAC 50Hz. Since then they have harmonized on 230 VAC 50Hz.

Small US manufacturers would often use dual primary power transformers and alternately wire the primaries in series or parallel to work in the different markets. Of course to work at 50Hz transformers need more iron so this was somewhat more expensive. Large manufacturers had the volumes to make unique transformers for domestic and export. Many older SKUs can have 220/240 switches to better accommodate the different countries power.

I recall encountering repairs because some customers switched to the wrong mains voltage to gain a little more power. Some did it innocently when working in regions with dodgy power and the extra voltage boost allowed the sku to work in some venues. Others did it less innocently. I recall doing at least one engineering change for a powered mixer amplifier module to increase the breakdown voltage of an anti-sat diode that could not handle the very high-line voltage.

Modern switching power supply technology has advanced to the point where universal power supplies can support 60-240VAC 50-60Hz. I was just starting to see these used in products at Peavey around the time I escaped (2000).

Note... we can comfortably run 50Hz transformers at 60 Hz but not as comfortable the other way around. Sizing all transformers for 50 Hz adds cost but it is still cheaper for small companies to use dual primary 50 Hz transformers, than using specialized transformers for each market.

JR

 

[transient]

For years the UK was 240VAC 50Hz while most of Europe was 220VAC 50Hz. Since then they have harmonized on 230 VAC 50Hz.

In reality, nothing changed. Only the tolerance windows were changed to allow everyone to stay the same but still be within spec! This is a good explanation:

https://www.twothirtyvolts.org.uk/pdfs/site-info/Explanation_230Volts.pdf

 

[JohnRoberts]

Yup... Back when I first got involved with selling SKUs into UK and EU (wasn't EU back then), we had to get agency approvals from each country. Now things are somewhat easier.

JR

 

[johnsonic]

I'd ultimately love to just swap the transformer to support US power. They don't list part numbers or specs for those, but does anyone have any ideas on how to locate one that's suitable? It's a Tascam AQ-65 by the way...

 

[Electrobumps]

I believe Tascam is US. So it is likely this will have an export transformer if it is currently wired to UK/European voltage.

As mentioned in my last post check the power TX for multiple taps on the primary. If you have an export TX you can wire brown and white for 120v and you do not need to purchase anything. It shows it in the USA digram.

If you are unsure or want to be cautious and use good practice use a variac to slowly power up and measure the 14v and 5v rail and make sure you do not go too far over them.

 

[expat]

Not sure if this info is of use, but I just moved back to the USA from Europe with a bunch of 220v gear. Since I have so much of it, and replacing transformers for everything is way out of scope, I just use a few step-up transformers. They're cheapish and get the job done for me. I have a 1000w and a couple of 250w ones. If you don't find the 120v transformer for your unit, you might consider just grabbing one and be done with it.

 

[JohnRoberts]

That direction works...

you could probably wire the step up transformers to euro outlet strips so you don't even need to mess with line cords.

That would eliminate mistaken plugins with wrong products.

JR

 

[13engrsapper]

it looks like it is throwing +14 after recification, and +5V after rectification and regulation.

 

[13engrsapper]

It is right in the schematic
The transformer in there will do it

 

[13engrsapper]

Looks like the transformer has Grey, Brown, Violet, and Red taps for primary voltage. So it will be connected to violet - Change the fuse to the one shown in the schematic for the US, undo the euro cap (or leave it if it is the correct type), and move the tap from violet to Brown. It looks to me like they made a multitap transformer, but often wired it per country to save some money, rather than installing the switched version "General Export"

 

[johnsonic]

I definitely have the UK version, and the primary wires are red/violet/white. US version has brown & white primary wires. So unfortunately I can't modify it to work (I think).

I did get a convert - thank you all! Works awesome.

In the future and for learning, does anyone know how would I go about specing an appropriate transformer if I did want to convert it to US power?