Stepdown Transformer 220V input 110V output.?

Question

Hi there.I have purchased a Stepdown Transformer so i can use a Record Cleaning Machine I am buying from the U.S.It uses a powered suction unit to clean the record.All transformers for use with American equipment have 110v output, but i think your equipment is usually 120v.in I have been told that there is nothing to worry about as 110v out on the transformer is enough to power the equipment connected to it .Our AC output in Australia is 240v but we can use any voltage from 220 to 250. Therefore 110v should be enough.
can anyone clarify and tell me it should be ok.Thanks a lot in advance.

Answer 1

I live in New Zealand. We use 240v 50Hz mains here too. USA uses 110/115v 60Hz. There is a 10Hz voltage frequency difference as well as the voltage difference.

The stepdown transformer will be rated for 110v RMS(root-mean-squared).

This is a kind of average, for want of a better description.
The peak voltage is 0.707 times the RMS voltage.
This is the peak on one half of the sine-wave(180'), therefore the complete sine-wave mains frequency represents 1.414 times the RMS voltage.(360' sine-wave cycle)

Multiply 110v by 1.414, and you will get the peak-voltage, which is the maximum that the AC voltage can swing, both in the positive and negative parts of the sine-wave.

110v example:

110 x 1.414 = 155, therefore, the PEAK voltage for the States is 155v AC, or thereabouts.

240v example:

240 x 1.414 = 339, therefore, the PEAK voltage for Aus/NZ is 339v AC, or thereabouts.

All mains voltages are a measure of averages(RMS), so a 10 or so volts either side of the stated voltage, should not prove to be a problem.

Provided that the stepdown transformer can supply at least a few amps of current on the secondary(the 110v side), there will be no problems at all.

Technically, the 10Hz frequency difference can make a slight difference, especially if you are trying to power some sound equipment from the States, as the Australian/New Zealand 50Hz frequency will mean that the motor will run slightly slower then the designed RPM.

However, in your case, I don't think it will make one iota of difference.
:)

Answer 2

Electrical appliances are designed to tolerate the range of voltage. Here in the USA the terms 110 and 120 are used interchangeably as are 220 and 240. Good luck mate!

Answer 3

I was in Germany for 2 years they are 220v also. I had a 110v step down and it worked fine with a TV VCR and a electric razor.