230v (EU) 50hz > 120v (US) 60hz - what to do?

Thread Starter

mrspanda

Joined Nov 2, 2022
15
Interestingly, you can't always assume that what you have is an autotransformer (or isolated transformer). I bought a low power 240 to 120V transformer from a supplier here in Australia, it actually had a warning label stating it was an autotransformer type, so out of interest I checked the resistance between input and output, which was infinite. So, I opened it up and there was a split bobbin fully isolated transformer. So, at some stage the design had been upgraded and yet the warning label was still being attached.
So, you can't assume either way, I would always test the transformer before using.
Let's assume I dont want to take any "risk" about whether its an autotransformer or not and just want to buy something I know is "safe". What would I go for?

I probably dont have enough knowledge to properly test resistance/whatnot... :(
 

Ian0

Joined Aug 7, 2020
10,276
Interestingly, you can't always assume that what you have is an autotransformer (or isolated transformer). I bought a low power 240 to 120V transformer from a supplier here in Australia, it actually had a warning label stating it was an autotransformer type, so out of interest I checked the resistance between input and output, which was infinite. So, I opened it up and there was a split bobbin fully isolated transformer. So, at some stage the design had been upgraded and yet the warning label was still being attached.
So, you can't assume either way, I would always test the transformer before using.
“Upgraded” is an interesting choice of terminology. An autotransformer would run cooler for the same size frame.
 

Ian0

Joined Aug 7, 2020
10,276
Let's assume I dont want to take any "risk" about whether its an autotransformer or not and just want to buy something I know is "safe". What would I go for?

I probably dont have enough knowledge to properly test resistance/whatnot... :(
Power tool transformer. It’s designed for safety! It also generally has a carrying handle and is fully waterproof,
As an extra bonus on the safety side, the maximum output is 55V, because it is a centre-tap-to-earth design.
 

Thread Starter

mrspanda

Joined Nov 2, 2022
15
Power tool transformer is the cheapest solution (but bear in mind that it is intermittently rated)
https://www.screwfix.com/p/carroll-...ep-down-isolation-transformer-230v-110v/61847
I have a 120V 60Hz Kitchen Aid mixer which is run that way, and I have also run a 120V 60Hz washing machine.
The Kitchen Aid's speed control doesn't work quite as well as I imagine it would on 60Hz.
Interesting to note that the cost of the Kitchen Aid at US prices, PLUS carriage, duty and VAT, PLUS the cost of the power tool transformer was less than the UK price of the Kitchen Aid.
Have you had any issues with the Kitchen Aid mixer overheating due to the frequency difference?
I guess thats my ultimately worry.

I have read a lot of posts about the theoretically consequences of the 50 vs 60 Hz being that the machine will run slower + possibly chance of overheating.

I've ofcourse not found a single post with an actual sewing machine use-case :)
 

Ian0

Joined Aug 7, 2020
10,276
Have you had any issues with the Kitchen Aid mixer overheating due to the frequency difference?
I guess thats my ultimately worry.

I have read a lot of posts about the theoretically consequences of the 50 vs 60 Hz being that the machine will run slower + possibly chance of overheating.

I've ofcourse not found a single post with an actual sewing machine use-case :)
No, it’s been fine, and I’ve given it some tough jobs like bread making.
It is probably a universal motor, and they will run off dc, otherwise a triac speed controller wouldn’t work. The washing machine had a capacitor-run induction motor, which, in theory, should have been in more trouble. The power tool transformer is 110V, not 115V, so the slightly lower voltage will have helped a bit.
 

Thread Starter

mrspanda

Joined Nov 2, 2022
15
Power tool transformer. It’s designed for safety! It also generally has a carrying handle and is fully waterproof,
As an extra bonus on the safety side, the maximum output is 55V, because it is a centre-tap-to-earth design.
I've been trying to find a similar transformer here in DK to the one you mentioned from screwfix (they dont do shipment to Denmark), but i've had no luck.
Also had a look on Amazon,- but not 100% sure what to look for (spec'wise).

Would anyone mind giving their opinion on whether the below (1+2) could be an choice for me?

Or as an possible alternative, whether any of the listed transformers on Amazon or this danish retailer would be better?
https://elektronik-lavpris.dk/c1740/stroemforsyninger-transformatorer/230vac-til-115vac/

Sorry for being so clueless about this. I received my machine now andwant to "make the better" choice for getting this to work.

1. Step Up/Down Voltage (I can get this one from 45W > 2400W)
Transformer • Toroidal Transformer
Input Voltage: 110V/200V/220V/240V
Output Voltage: 110V and 220V
Input Frequency: 50Hz/60Hz
Max. load: 1500W
Efficiencydegree: 98%
Certification: CE, ROHS
1667900505677.png

2. (half the price of nr. 1)

Coord: Schuko / Type F (CEE 7/7)
Effect: 300 W
Output current: 2.7 A
Output Voltage: AC 110 V
1667900962996.png
 

Janis59

Joined Aug 21, 2017
1,863
Some US sailors near vodka store sold me very powerful 450 mm angle grinder so lurefully cheap I was not able to stand and bought. At home I realized that 110 V 60 Hz problem. Used thyristor regulator - machine gave very tiny power and overheated. Changed power dimmer toward the LATR (transformer). Power became better but anyway machine overheated. Then applied the TL494 with ferrite core DIY transformer thus the machine now works fine.
 
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Thread Starter

mrspanda

Joined Nov 2, 2022
15
Some US sailors near vodka store sold me very powerful 450 mm angle grinder so lurefully cheap I was not able to strand and bought. At home I realized that 110 V 60 Hz problem. Used thyristor regulator - machine gave very tiny power and overheated. Changed power dimmer toward the LATR (transformer). Power became better but anyway machine overheated. Then applied the TL494 with ferrite core DIY transformer thus the machine now works fine.
Everyone knows it's impossible to refuse drunk sailors with great angle grinder offers!!
Thanks for sharing your way towards a working setup - im sure it can be helpful for future visitors.

I'm sadly not that technichal, so the last part you describe is jibberish to me :D If you know some drunken sailors that sell a finished plug n play product that you got working, i'd be so excited to hear about it
 

Ian0

Joined Aug 7, 2020
10,276
Some US sailors near vodka store sold me very powerful 450 mm angle grinder so lurefully cheap I was not able to strand and bought. At home I realized that 110 V 60 Hz problem. Used thyristor regulator - machine gave very tiny power and overheated. Changed power dimmer toward the LATR (transformer). Power became better but anyway machine overheated. Then applied the TL494 with ferrite core DIY transformer thus the machine now works fine.
I'd just have needed to plug it into my power tool transformer (after changing the plug).
 

Thread Starter

mrspanda

Joined Nov 2, 2022
15
Thanks for the link Ian.

Would any of the RS Pro ones be fine? (I hardly understand the specifications)
I can see they're sold from the UK and thus with UK plug (which is a bit bummer... Mostly because of customs import etc.).

I should just be able to change the plug to a danish one without any hazzle, right?
 

Ian0

Joined Aug 7, 2020
10,276
Thanks for the link Ian.

Would any of the RS Pro ones be fine? (I hardly understand the specifications)
I can see they're sold from the UK and thus with UK plug (which is a bit bummer... Mostly because of customs import etc.).

I should just be able to change the plug to a danish one without any hazzle, right?
Yes. Provided it's a plug with an earth pin.
They will all be intermittently rated, but I guess you won't be using a sewing machine for any longer than you would use a power saw.
I wonder if any other country requires low voltage tools for building sites?
 

Thread Starter

mrspanda

Joined Nov 2, 2022
15
Yes. Provided it's a plug with an earth pin.
They will all be intermittently rated, but I guess you won't be using a sewing machine for any longer than you would use a power saw.
I wonder if any other country requires low voltage tools for building sites?
Excellent, plug-swapping I can do :)

The machine could in some rare instances run 10-15 minutes, im not sure if such running time could become an issue?
 

Ian0

Joined Aug 7, 2020
10,276
Excellent, plug-swapping I can do :)

The machine could in some rare instances run 10-15 minutes, im not sure if such running time could become an issue?
I doubt it. You could easily run a power tool for that length of time (especially if it’s an angle grinder, and you are an untidy welder)
 

Thread Starter

mrspanda

Joined Nov 2, 2022
15
I doubt it. You could easily run a power tool for that length of time (especially if it’s an angle grinder, and you are an untidy welder)
I might soon be out of stupid questions, but have one more, riiight from the hip:

The sewing machine specs says 45 watt -> using a power tool transformer with the capacity of A LOT more watt - like the RS Pro 750VA (not sure how many watt that converts too) - will that cause any issues? Or does the machine just "consume" whatever watts it needs = it doesnt really mather whatever more capacity the transformer has
 

Ian0

Joined Aug 7, 2020
10,276
I might soon be out of stupid questions, but have one more, riiight from the hip:

The sewing machine specs says 45 watt -> using a power tool transformer with the capacity of A LOT more watt - like the RS Pro 750VA (not sure how many watt that converts too) - will that cause any issues? Or does the machine just "consume" whatever watts it needs = it doesnt really mather whatever more capacity the transformer has
750VA = 750W assuming unity power factor.
It will not even be tepid at 45W
 

Thread Starter

mrspanda

Joined Nov 2, 2022
15
I feel embarassed ... I have no idea what "tepid" means... Never encountered that word before, lol!:oops:
Given the context, are you saying: That the machine will fit excellent with 750VA, since it's specified with 45W = it will never really use much of the power tool transformer max. capacity?

Sorry for all the silly questions... Really just trying to make the right choices,l before spending too much further...
 

MrChips

Joined Oct 2, 2009
31,086
Brother SE600

I cannot find the power specifications for the machine. Where did you see the 45W specs?
This seems very low for a sewing machine.
 

Thread Starter

mrspanda

Joined Nov 2, 2022
15
Brother SE600

I cannot find the power specifications for the machine. Where did you see the 45W specs?
This seems very low for a sewing machine.
I found those specs from the manufacturer on their Amazon page:
https://www.amazon.com/ask/questions/Tx157Q40GE9JRAQ/1

And after having received my machine,- it's also on the machine label :)
But yea, for some reason very hard to find those details online... Even more impossible to find anything about the motor in the machine...

1668009427904.png
 

MrChips

Joined Oct 2, 2009
31,086
I found those specs from the manufacturer on their Amazon page:
https://www.amazon.com/ask/questions/Tx157Q40GE9JRAQ/1

And after having received my machine,- it's also on the machine label :)
But yea, for some reason very hard to find those details online... Even more impossible to find anything about the motor in the machine...
Ok, thanks.
In that case the 70W adapter you showed in post #14 should work fine.

I tried searching for a suitable step-down transformer. This is what I found from the German site.

https://www.amazon.de/Fahrspannungs...nsformator-Fahrwege/dp/B0946JBJT6/ref=sr_1_22
 
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