Step-Down Converter Vs. Voltage Converter?

[tangcoral]

I brought an air purifier from US that runs only on 120 volt using 80watts max.

Anyhow I went to Amorn today and saw that they have two types of voltage transformers.

1. "Step-down converter" looks like a ugly block of transformer and printed on the box "designed for 120volt appliances used in countries with 220-240volt.

With a picture of arrow going one way "220/240V -----> 120V"

2. "Voltage converter" looks like a powder coated high-end power supply for PC with led and switch. Printed on the box " "designed for 220V appliance to be used in countries with 120V or 220V

With a picture of arrow going both ways "220V <-->120V" There's and input volt switch for 120 or 220

Now why would you use a voltage converter for 220V appliance in a country that supplies 220V?

What am I not understanding and which one should I have gotten or doesn't matter as both would work for my application?

Edited October 9, 2010 by tangcoral

[InterestedObserver]

1. Does your air purifier run on 50 cycles by any chance?

2. A 2:1 (240V to 120V) step-down transformer, rated a minimum 100VA, is the easiest solution.

3. Without knowing what's inside the "voltage converter", I'd stay away from it.

Edited October 9, 2010 by InterestedObserver

[tangcoral]

The air purifier is rated for 60 cycle, but this is a less concern as only the motor speed would be slightly lower on 50 cycle

I just wanted to know what the difference between step-down vs voltage converter

[Crossy]

Same same but different.

The step down unit is intended to give 110V in a 220V country only, the converter goes both ways (usually automatically) 220V in = 110V out, 110V in = 220V out (well that's what mine does anyway, YMMV)>

[Pib]

Agree...same with my four 80 watt power converters. They go both ways...120 to 220V and 220 to 120V with a flip of the built-in switch next to the line inlet...expect the switch only controls/reverses which sides the input line voltage goes to and outpput voltage comes from on the internal transformer. Usually the power/voltage converter that can go both ways costs a little more since a switch has to be built/wired in compared to a coverter than just goes one way and don't use a switch. Having a converter that goes both ways just adds flexibility if you travel the world with it.

Below is a few pictures of the converters I've used for the last couple of years with various 120V devices (ie., hand held hair dryer & curler, printer, cordless phone, etc)...each one cost around 250 Baht at Pantip in Bangkok, but you can find them in a lot of places at various prices. Just be sure to get one that gives you a little spare "wattage" capacity....that is, if your max load is going to be 60watts (60VA), get a 80W or 100W converter, etc. The wattage of the item you plan to power should be printed on the power rating sticker/plate (e.g., 120V, 60W; 120V, 2W, etc). And just because you will be plugging the converter into 220V does not change the wattage rating of the item you are powering.

Edited October 10, 2010 by Pib

[lopburi3]

1. Unless your fan is DC powered (expect it is not) it is likely to run slow and hot as 60Hz motors, especially for sale in USA, are as cheaply built as possible. This will effect the cleaning ability and could present a fire hazard.

2. I would never buy a local transformer rated only 20% higher than continued requirements. They are also built cheap and often over-rated.

[Tywais]

Need to be cautious about items with the term "converter" in them and they show a rating of kilowatt or more as these are simply diode devices that supply only half cycle of the ac power. Normally used with hair dryers or similar high power travel devices.

[gotlost]

Need to be cautious about items with the term "converter" in them and they show a rating of kilowatt or more as these are simply diode devices that supply only half cycle of the ac power. Normally used with hair dryers or similar high power travel devices.

I agree with you on this. A converter to me is converting DC to AC not step up or step down voltage. You may want to look at this article.

http://en.wikipedia.org/wiki/Voltage_converter

[Pib]

No shortage of power/voltage converters for sale. Just take a look at this Ebay query/listing for "power converter."

http://shop.ebay.com/?_from=R40&_trksid=p3907.m570.l1313&_nkw=power+converter&_sacat=See-All-Categories