Devices to convert 240 v, 50 H to 120v 60 Hz?

What are these called? and where could I buy them in various wattages, say

10w, 50 w, etc, or is it KVAs?

TIA

rf

Reply to
RedFox
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i would call it a power supply and an inverter.

you obtain a power supply that operates from 220 - 240 VAC @50 Hz. it outputs 12 - 13.8 VDC.

the inverter then runs on 12 VDC and outputs 120 VAC @ 60 Hz

you might be able to find an all in one box somewhere but my guess would be the price would be high and it probably will be a special order

Reply to
TimPerry

What do you want to run? You may not need to change the frequency.

Reply to
John G

Thank you Tim and John.

Electronics - receiver, amplifier, speakers, tape units, cine projector, and small power tools.

TIA

rf

Reply to
RedFox

Some of those devices need a local (110v) wall wart just like the 240 volt one that came with them and most of the rest will more than likely run from a 110 to 240 volt transformer and be happy with the 60 hertz. It is really not possible to be sure without seeing and reading the name plate on each device. Or it may turn out cheaper to buy a local equivalent device.

Reply to
John G

I am not sure whether you have 240v 50 Hz equipment that you want to run off 120 volt or a 240 v supply that you want to use to power 120 v equipment? You could have just moved to your present posting time zone - or you could just be preparing to move from it - so that doesn't help either.

Converting voltage is a doddle:

Many bits of electronics kit these days will work on either

- maybe with the need to slide a voltage selector switch on the box.

Many use an external power brick and the manufacturer/ local electronics shop can provide a suitable replacement.

You can buy "autotransformers" in various wattages values from a few watts to a few kW. These typically have a "normal" socket on them that you can just plug your foreign unit in to. Your power tools may need one of these.

There are other converters - some which simply use a power rectifier to allow 120v units to run off 240v. I wouldn't use one with anything in your list..If the converter feels very light, it is probably one of these.

Converting frequency is much more difficult and expensive.

Unfortunately your tape decks, record players and projectors may need it because they may use drive motors with speed determined by supply frequency. Sometimes they have mechanical ways of allowing for 50 or 60 Hz - eg a sleeve that can be fitted/removed from a shaft, two positions on a pulley wheel. Or an alternative (often user-fitted) rotary part from the manufacturer that can be fitted as a replacement.

Failing that - one option is to use a portable generator. I know one person who shipped a generator home with everything else. This probably won't apply in your case, but I thought that I would mention it.

Otherwise, you need either inverters or rotary converters. The latter are mostly for kW and tend to be expensive and make a noise - but I have several government/army surplus ones that only cost a few pounds and will probably last longer than I will. They produce really excellent, low noise, electrically isolated, outputs.

Inverters are electronic bits of kit that take the input supply, convert it to dc and then rebuild a sine wave at the right frequency and voltage. Some produce a pretty good sine wave out - others don't. The problem with a poor sine wave is that it produces harmonics that can be very audible and practically impossible to get rid of, if using radio or audio equipment. It isn't always obvious, from the technical description, as to whether a particular inverter will be good or bad, in this respect. You really need to try it.

They come in a wide range of power outputs and a very wide range in cost.

So, basically, it would be best to go through everything and reduce to a minimum that which really must have the "right" voltage and frequency. Then consider replacing them! Then buy an inverter(s) stating clearly what the intended purpose is - in the UK, at least, that will allow you to return it and get your money back, if it does produce too much interference with your audio/radio.

Reply to
Palindr☻me

What makes and models of film projectors? Many of them can be changed to run on the other frequency. Some tape recorders can also, e.g. by moving a belt to a different step on a pulley.

Reply to
furles

Thank you John G, Palindr?me and Furles, for the very helpful comments.

My film projector is German made so it should be ok, though I'm not sure how it copes with the frequency change. It's out of my reach at present so I can't look at it. As Furles suggested, I have a DUAL turntable that has a voltage switch 220-110 and a replacement pulley. The tape recorders I have not looked closely at but will soon. With a VCR there is a double problem - the TV format, in addition to the frequency difference. Another of the problem pieces is a Sony receiver that has a plate mark of 110 v, 60 Hz and no change possibility. I asked Sony about 220v 50 Hz and they said to use an AVR, or something like that. I asked what they meant and didn't respond. I did a search and came up with zillions of hits of all kinds. Somehow I had expected fairly inexpensive 220 - 50 Hz => 11- 60 Hz for small items around 20 watts but haven't identified any.

Thanks again.

rf.

Reply to
RedFox

Well, domestic VCRs are effectively obsolete now anyway and new ones are very cheap. But I would transfer the tapes to DVDs and move on.

For AVR, read autotransformer. OK, you can get autotransformers with switched taps that act as an "Automatic Voltage Regulator" - to allow for very variable utilitiy supplies. You probably won't need anything that complicated or expensive and a simple 220 > 110 volt autotransformer will do. Maplin (UK) have one rated at 100W:

formatting link
Note that these do NOT change the frequency - but only the voltage. So typically it will change 220-50Hz => 110 - 50Hz

If the Sony receiver is also a mains-driven alarm clock - you will have problems. It quite possibly won't keep accurate time. There is often a link on the clock board inside that can be made or broken to allow for mains frequency (much like the mechanical equivalent of a sleeve on a shaft or a pulley change, as I suggested for mechanical kit) so it may be possible to fix this - but the link is probably soldered and you need someone used to working with asoldering iron on electronics, if you aren't.

Reply to
Palindr☻me

Caution>>>>>>>

AUTOtransformers are not permitted in most 230volt countries because it is possible to get your 110volt device connected to the 230volt hot and a tap half way down instead of the neutral and a tap halfway up. I would be very surprised if they are allowed in the UK but then I do not know where you or the OP are.

Really the simplest answer to all this is to uy new devices at the new location. (What a great excuse to update.)

Reply to
John G

"Most"? I hadn't realised that, would you like to list a few?

They are certainly widely available in the UK. If you would like to go to rswww.com and search on "autotransformers" - you would find everything from a few tens of watts single phase to rather larger three phase.

The ones intended for "consumer" use have a permanent mains lead with a moulded on plug - the UK plug is polarised and the problem that you mention cannot happen unless the wiring infrastructure is incorrect.

Reply to
Palindr☻me

There's no problem in the UK, as our mains supplies are polarised and live/neutral distinction maintained into appliances. Most other parts of Europe do not have polarised socket outlets though.

Reply to
Andrew Gabriel

Thanks Andrew for the coments. I will be moving to Portugal, possibly later to Spain. I'll watch for that possible polarization problem

rf

Reply to
RedFox

That's exactly my plan but I don't have the time before I move.

Thank you. Thank you. Thank you :-)

The Sony doesn't have an alarm clock but it may have a timer. It's been a while since I had a close look.

I'll make a note of your comment and will investigate it. I have used soldering irons mannnnnnnnnnny times.

rf

Reply to
RedFox

Thanks JohnG, and Sue again for your help.

rf

Reply to
RedFox

Yes I thought afterwards I should have said SOME rather than most.

But it is still possible to buy 13amp plugs in the UK and misswire anything. (RS pt no. 490-009 for instance)

AND some autotransformers listed by RS are commercial (rather than consumer) with terminals to be miss wired with ease.

So my caution remains even if it is not recognised as a problem in some countries.

Reply to
John G

| AUTOtransformers are not permitted in most 230volt countries because it | is possible to get your 110volt device connected to the 230volt hot and | a tap half way down instead of the neutral and a tap halfway up.

I know at least in Schuko plug countries, and compatible, polarization is not applied to the plug pins, so either one could be grounded. That's why an autotransformer is unsafe. The type of plugs used in UK and AU could be polarized since there is only one way to plug them in. Since I have heard that Argentina uses the same plug as Australia, but with the polarization reversed, that would imply there is a standard in these countries. But of course there is the risk when 110 volt users travel to these countries.

The plugs in the USA appear to have been polarized (the grounded slot is larger) for quite a long time. I recently saw a receptacle that was made in 1920, and it was polarized.

| I would be very surprised if they are allowed in the UK but then I do | not know where you or the OP are.

Just use a full isolation transformer.

Reply to
phil-news-nospam

On 15 Aug 2005 12:59:50 GMT Andrew Gabriel wrote: | In article , | "John G" writes: |>Caution>>>>>>>

|>AUTOtransformers are not permitted in most 230volt countries because it |>is possible to get your 110volt device connected to the 230volt hot and |>a tap half way down instead of the neutral and a tap halfway up. |>I would be very surprised if they are allowed in the UK but then I do |>not know where you or the OP are. | | There's no problem in the UK, as our mains supplies are polarised | and live/neutral distinction maintained into appliances. | Most other parts of Europe do not have polarised socket outlets though.

In most cases there should be no need for this. Everything metal that does not need to conduct power should be grounded. Edison style light sockets (screw-in base) make it easy to get shocked on the shell. But as big as they are, one could touch the center contact, too, so they are bad news in general. When I build my house, I will have NONE of them around anywhere. I'm still trying to choose what to have in their place. I have heard they are no longer allowed in Germany. Maybe I will have to do my light hunting in Europe and figure out how to comply with the voltage limitations for lights in the NEC (US electrical code). I may well go with 12 volt lighting all over.

Reply to
phil-news-nospam

hei,

Could be Autotransformer (technology moving fast). Whatever power or voltage or else you need, the input should have nominal percentage allowed (+ - ). This means too ideal to get actual figure.

tks

magic

Reply to
magic

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