Help running U.S.A appliance in Australia

Factual Questions
1

Hi all,

First off, let me just say that electronics make my head hurt. I’m neither factually nor intuitively very knowledgeable in this area. Despite this I love gadgets and devices and buy them all the time.

That said, I was hoping someone could advise me what sort of device I need to run an appliance from the U.S.A from an Australian power outlet.

Here’s what I know: The device in question (base station for a set of wireless headphones) has an (American) power adaptor stating it takes 120v, 60Hz, 3w and outputs 9v, 200mA. Australian power outlets output 220-240v at 50Hz.

I have a step-down transformer, which plugs into an Australian outlet and outputs 115v. It also say ‘50w’ on it, which I’m guessing applies to it’s output (?). The transformer’s outlet is clearly designed for an American plug, so I’m (again) guessing this thing was designed for doing what I want to do.

Will this transformer work to power the device without frying it any way? Does it matter that it only outputs 115v and the device wants 120v? Also, is there something I should be doing to deal with the watt/hertz differences? At the moment I’m being a wimp about plugging it in lest the God of Electricity come forth to smite me and my sexy new headphones.

Thanks to anyone who can help!

2

You might be better served by getting a new DC adaptor that plugs into Aussie mains and puts out 9V, 200mA DC - which is what your base station wants.

Failing that, there’s no reason why your current step-down transformer won’t work - the difference between 115 and 120 volts will not make any difference to the output of the transformer, and neither will the frequency (Hz) difference.

The 50W refers to the maximum capacity of the step-down transformer - you’re well under that, so there should be no problem.

I think the God of Electricity has been appeased sufficiently for you to plug in your headphones with equanimity, but you might want to wait for another few responses.

3

According to this site, you should be OK with your 50W converter. I have little personal experience with foreign power conversion, though, so I can’t confirm this.

4

My gut feel is that you’ll be OK. I know there’s a bit of tolerance in power supply (such as appliances not giving a rats whether it’s 220v or 240). It seems kosher to me, but add me as another one not wanting to have his word taken as gospel for this until a grow-up comes along.

The “buy an Australian transformer” advice seems sound too - I am wary of adaptors for overseas stuff - especially going from US to AU and not vice versa. I don’t know why, but I am. Maybe it’s not entirely rational.

5

Thanks guys, at minimum I wanted to be sure I was thinking through it the right way by confirming that it sounded right to others as well.

So I plugged it in. It appears to be charging my headphones and thus far there have been no explosions or deities.

Loaded Dog, I know how you feel. I only own a few other US devices, though they all have tolerance for Australian voltages built-in to their adapters - and even when I first plugged them in I was thinking ‘Should I be doing this? Will things explode? Surely this is in some way not right? This has to be both dangerous and wrong. Maybe I’ll make someone else plug it in…’

So - thank you all for your advice! I look forward to many hours of wireless, neighbour-friendly music

6

Buckler of Swashing, I work as an Assistant Manager at an electronics store and spend a surprising amount of my day dealing with enquiries like yours- so don’t feel bad, you’re not the first person to ask this question! :slight_smile:

The easiest option is to buy an Australian 9v 200mA AC Adaptor- you can get one from Dick Smith Electronics or Tandy for about $30 or so, and it will work quite happily with your American rechargeable headphones. Check the Amperage rating, though- most of them are around 500mA-1A, which means you really shouldn’t make a habit of leaving the unit plugged in any longer than you have to, or over time it will cause problems.

Also make sure you get the polarity right or you’ll bugger the unit- I’d recommend you take the unit into the store with you and ask the salesperson to put the tips on the adaptor for you, so you know it’s 100% right. They’ll be happy to do this for you- it only takes a moment- but preferably not when the store is packed with people. :wink:

MOST appliances with AC adaptors these days are dual-voltage. Have a look on the adaptor; if it says Input 100-240v 50/60hz (or something near enough to that effect) you can plug it in anywhere in the world and it won’t spontaneously combust or cause a plague of locusts o’er the land.

Or, if you like, you can continue to use your stepdown transformer and US AC adaptor, which will function just fine. But it’s a bit convoluted and inefficient, somewhat like making coffee by boiling the water in a saucepan when you’ve got a perfectly good Russell Hobbs kettle in the kitchen. :slight_smile:

As a general rule, though, don’t buy electronics in the USA, Canada, Japan, Mexico, or Spain unless they have a replaceable AC Adaptor or are Dual Voltage; the expense involved in converting them from 110 to 240v power invariably outweighs the cost of buying a similar item when you get home. We get a lot of people wanting to buy power converters so they can take hair-dryers or hair-straighteners on holiday to the US with them; my advice is to simply not bother, find a WalMart/Walgreens/Target when you get there, buy a hair-dryer/hair straightener for $30, and then leave it in the US when you come home.

The same goes for people from the US/Canada holidaying here- go to Kmart or Target and get a 240v model here instead of carting your hair-dryer or hair straightener halfway across the planet only to discover you can’t plug it in.

7

Thanks heaps for the information, Martini Enfield! I feel I actually know what’s going on.

I can appreciate your saucepan/kettle analogy and I will definitely buy a new, less cumbersome adapter tomorrow :slight_smile: .

I only brought this unit from the US because they were on sale at an online store and even with the international postage and the price of the new adapter, it was $100+ cheaper than I could find it in stores here in Australia. That’s my excuse.

8

This is good advice. Most transformers that you buy on the commercial market for appliance use are auto-transformers. Reversed polarity raises hell with electronics plugged into this situation, and can also pose a shock hazard. Isolation transformers don’t pose the same risk.

9

One of the best sig to post matches I’ve seen in a while!

Brings up an image of someone sitting in their lair and unable to plug in the Evil Device.

10

I used to run a Radio Shack, and heard that from many customers/“electronic experts” over the years, but it’s simply not true, though the reverse condition can be.

The adapter is a voltage regulated device, and will allow up to 500mA or 1A (depending on the actual value on the adapter) as the power requirement of the connected device calls for it. Power = Voltage x Current, and as the voltage in this case is fixed at 9v, when the power consumption goes up, it does so due to additional current going into the device. The same applies in a downward direction.

If you had a device that called for 1A, and you plugged it into an adapter capable of only 500mA, you could have a problem, as the adapter isn’t rated for that much current, and as a byproduct, heat produced that needs to be transfered into the air around the adapter.