230v 50Hz to 110v 60Hz Frequency Change

[ParkingLotLust]

I realize it may be 230v to 115v or 220v to 110v, but by "240v to 120v" I mean stepping down the outlet voltage from, say, England to Canada. I know that the voltage can easily be changed with a transformer, but how do you change the frequency from 60Hz to 50Hz, or how is it done in a commercial step-down converter?

 

[MikeMl]

Frequency change can be done by rotating machines (sync motor driving an alternator).
I have some large CH single/three phase several HP motor drives which can accelerate a motor smoothly; ero they change frequency. AFIK, they use large capacitors to store energy cycle by cycle, and switch mode drivers to synthesize the output waveform at another frequency.

 

[eblc1388]

I know that the voltage can easily be changed with a transformer, but how do you change the frequency from 60Hz to 50Hz, or how is it done in a commercial step-down converter?

One method is to generate a frequency 10 or 12 times the input using PLL technique and then form an AC waveform directly from this via a ring counter.

The ring counter circuit(shown in image) accepts ten times the input frequency and build a waveform with 1/10 of its input frequency.

The following image shows how a 60Hz output signal is being generated from a 600Hz which I obtained via a full wave rectified AC 50Hz waveform and then X 6 using a PLL.

Another method involves using a PIC to generate the required output using PWM and frequency lock the output to the input frequency such that the number of cycles fulfill the frequency ratio of 50/60Hz. All the hard work is done via coding and the output is a nice clean frequency. However, your PWM coding must be able to output a frequency range between 57~63Hz and with frequency resolution of 0.02Hz or better, e.g. 60.00Hz for 50.00Hz and 59.98Hz output for a 49.99Hz input.

 

[Nigel Goodwin]

I realize it may be 230v to 115v or 220v to 110v, but by "240v to 120v" I mean stepping down the outlet voltage from, say, England to Canada. I know that the voltage can easily be changed with a transformer, but how do you change the frequency from 60Hz to 50Hz, or how is it done in a commercial step-down converter?

It generally isn't (I've never seen any such converter), as it's FAR too expensive - simple auto-transformers are what you get.

However, there's hardly anything which needs 50 or 60Hz, most things work equally well on both. Do you have a specific need in mind?.

 

[ParkingLotLust]

Thanks for the great reply!

Nigel, I do a lot of travelling and my parents tend to bring along their little stepdown converter, I was just curious how (if) it did the frequency change. I figured they didnt because it just looked like a big transformer, but that got me thinking as to how it could be done in the first place. So no, no specific need, just idle curiosity

 

[Nigel Goodwin]

Thanks for the great reply!

Nigel, I do a lot of travelling and my parents tend to bring along their little stepdown converter, I was just curious how (if) it did the frequency change. I figured they didnt because it just looked like a big transformer, but that got me thinking as to how it could be done in the first place. So no, no specific need, just idle curiosity

It will just be a transformer.

 

[ecerfoglio]

It generally isn't (I've never seen any such converter), as it's FAR too expensive - simple auto-transformers are what you get.

However, there's hardly anything which needs 50 or 60Hz, most things work equally well on both. Do you have a specific need in mind?.

It depends on what are you driving with the "converted" voltage.

Allmost all of the electronic "gadgets" will work on 50 Hz as well as on 60 Hz.

Some (like clocks that use line frecuency as a reference) wont, and it's ussually cheaper to get a new clock than to convert the frecuency.

Some machines (those with AC motors) will work but at the "wrong speed" (eg a 1800 RPM 60 Hz motor will spin at 1500 RPM at 50 Hz)

 

[Nigel Goodwin]

It depends on what are you driving with the "converted" voltage.

Allmost all of the electronic "gadgets" will work on 50 Hz as well as on 60 Hz.

Some (like clocks that use line frecuency as a reference) wont, and it's ussually cheaper to get a new clock than to convert the frecuency.

Some machines (those with AC motors) will work but at the "wrong speed" (eg a 1800 RPM 60 Hz motor will spin at 1500 RPM at 50 Hz)

Like I said, hardly anything.

 

[richwit]

230/110 stepdown

this might help +/- 10 years ago while on business in Seattle i purchased a set of cordless phones and knowing i would need a convertor for home[south africa] where the voltage is anything from 240v to 210v and the phones worked off 120/110v for american use, i purchased a"Brookstone" stepdown transformer rated at 85 watts[made in China ,bought in u.s.] which is what mainly europeans need for their u.s. acquired fax machines,answering machines,game consoles,tape decks and just about any electrical home appliance including battery chargers that run on 120v[not suitable for kettles ,irons or high current draw appliances] dimensions are 100mmx100mmx60mm and around 3/4 kilogram in weight

 

[MrAl]

Hi,

Some converters even high powered ones are made by rectifying the input line into DC with some filtering and then chopping it up with a transistor bridge that synthesizes a sine wave at the required frequency, then stepping up or down with an output transformer and filter. Typical are 50, 60, and 400Hz outputs.

 

[crutschow]

richwit, why did you reply to a two year old thread?

 

[Reloadron]

richwit, why did you reply to a two year old thread?

It's a necro thing.

Ron

 

[manishswarnakar@gmail.com]

My friend from USA gifted me Yamaha Home theater. How can I use this in india condition? does directly connecting this from power will burn my system?? also If I use transformer 240V - 120V then do I need to change the frequency also and if not then what will be consequences..

 

[MikeMl]

My friend from USA gifted me Yamaha Home theater. How can I use this in india condition? does directly connecting this from power will burn my system?? also If I use transformer 240V - 120V then do I need to change the frequency also and if not then what will be consequences..

Look at the specifications page of the owner's manual. It will specify the allowed range of input voltage and power line frequency. It may turn out that the equipment will accommodate your local conditions automatically; if not, then you will likely only need to use an external device to change the voltage, and the frequency will be ok...

 

[Dishul]

Hello all, I realise that this is a very old thread but I have been searching everywhere for an answer to a problem I have and I 'm really hoping that somebody here can help me.

I recently bought a Brondell Swash 1400 bidet toilet seat from the USA. I live in the UK and I had assumed that I would be able to run it on a step down transformer (240v to 120v) without any problems.

This didn't however work out. I contacted Brondell for help and they informed me that the product needed a 60hz supply opposed to the 50hz that we have in the UK and that there was no way to convert the supply. The product cost me £600 so you can imagine my motivation to find a way to get it to work.

It did occur to me that the answer might be to convert our 240v 50hz supply to 12v DC them run it through a USA built inverter to give me 120v 60hz. Could anybody tell me if this would be feasible. The product needs 1200watts.

Any help with this problem would be hugely appreciated, thank you.

 

[Reloadron]

It did occur to me that the answer might be to convert our 240v 50hz supply to 12v DC them run it through a USA built inverter to give me 120v 60hz. Could anybody tell me if this would be feasible. The product needs 1200watts.

Since these things use a on demand heater I can't guess, unless there is a motor involved, why it wouldn't work on 50 Hertz> Anyway, if these things are that fussy about mains power line frequency and you run with a 120 volt 60 Hz. UPS you may want to make sure the UPS inverter out is a TSW (True Sine Wave) rather than the more common and less expensive MSW (Modified Sine Wave) type inverter. Again, I would have thought it could be run off a transformer as long as there was enough power. Living in Italy for 3 years I ran a full size 18 cubic foot US specification refrigerator / freezer on a transformer using the 50 Hz Italian power. The compressor did just fine. Make sure the inverter can handle the minimum 1400 watt load, I would look for a 2.0 KW unit with 2.0 KW True Power as a TSW.

Ron

 

[ronsimpson]

I contacted Brondell for help and they informed me that the product needed a 60hz supply

There is your first problem. You talked to some one that has the same manual in his hands. Probably knows nothing more.

I can not think of a reason unless there is a clock inside. I would just connect it up and give it a try. Then it is your £600 not mine.

 

[MrAl]

Hello,

Maybe it has a fussy induction heater.
Motor will run a little slower on 50Hz if it is not universal.

They make frequency converters that do not need you to push the voltage down to 12v just to get the right output AC voltage. That's not that good of an idea really if you can find a regular frequency converter.

Of course you should check your "transformer" to make sure it works properly first.

 

[Dishul]

Thanks so much for your help, I'll let you know how I get on.

 

[schmitt trigger]

Archeological thread....

Thank goodness that nowadays chargers for portable electronics are completely universal. They will work from Japan's 100VAC supply to Australia's 240VAC supply, 50 to 60 Hz.