120v to 100v step down transformer for Japanese consoles in the US?

I just bought a Japanese 3do. The power supply says 100v on it. The system runs just plugged straight into the wall, but it was expensive and its old, so I kind of want to baby it and not stress out the proprietary built-in internal transformer.

After doing some research, I see that many people recommend using a step down convertor for older Japanese systems such as the famicon and super famicon.

I did some more research and was slightly shocked to see how pricy 120 to 100 v step down convertors are (like $40+), especially when 220<>120 or 220<>100 are much less.

Does anyone have any recommendations for an affordable step down transformer for 120 > 100 v?

 

Most of these transformers have some tolerance built in because power isn't a perfect 60hz sine wave at 120v even. It varies.

Babying it likely won't do any good and replacing the transformer isn't difficult.

 

I have a japanese ps1 and have no problems running it,I'm in the US,also the fami and super fami use external power supplies so you could use a sega genesis model 1 psu,no step down needed.

 

Most japanese consoles with switching PSUs will work fine with any voltage in 65-125v range. Never had any problems running with either DIY step down transformer from medical equipment PSU (70v) or with 220 to 120 one. 19 years and no problems so far.

 

Not much market here. It's regarded safe enough for common devices, Americans have little interest in importing the PAL consoles who more clearly need it.

 

Above posts are all on the money.

Also, how is $40 not affordable? You get that in raw material, just about.

$40 is pocket change in vintage gaming terms.

 

A switching PSU will normally be fine. A standard 100v transformer (eg, SFC or MD PSU) however, won't be so happy on 125v and may overheat slightly. The extra 25v AC will also mean an increase on the DC secondary. Not really a problem, as the console has a voltage regulator but still not ideal.

 

Don't be afraid, transformer won't overheat that much from 10-15 extra volts, and 7805 can handle up to 30 volts without any problems (with proper cooling of course, CDX/MultiMega + more than 12v PSU - very bad idea). And 100 to 125 won't give you more than a volt or two. Nothing to worry about. Also APE right about one thing - AC equipment is designed to work with voltages 15-20% higher than nominal, because power isn't that stable, especially in rural areas, so all european equipment can handle 250v, american - 130-140, for japanese stuff 125v will be ok.

 

I thought America was 110v? I have a US step-down transformer and it says 110v on it. Anyway, I use this transformer to play my Japanese consoles, no problems at all.

 

Sorry to bump an old thread, but did anyone ever bite on a 120v to 100v step down. I found a couple online for around $25-$30 (Link to one) but I wanted to know if anyone has opinions before I jump on one.

 

There is really no need for one eg: 120v to 100V

 

The nominal voltage is 120V, what you actually get is slightly more complicated.

http://www.faqs.org/faqs/electrical-wiring/part1/section-14.html

In the UK we've officially changed to match the rest of europe, but the reality is slightly different

"In the UK the nominal supply voltage is 230 -6% +10% to accommodate the fact that most supplies are in fact still 240 V"

 

Amperage is a draw, which means you can use the amp value as a minimum value and need not be exact. It will only use as much as it needs. It is voltage you need to match up as close as possible.

 

Not really. If PSU is regulated, then a few more amps won't make any difference, for example 3A instead of 0.5A means only that PSU will heat less.

 

I decided to bump this thread, because I recently purchased an FM TOWNS II HR model computer and it sometimes powers off when running it through US power without a voltage converter. I did some research and I keep bumping into this:

http://www.amazon.com/VCT-VT-500J-Japanese-Transformer-Converts/dp/B000PC4JL4

I asked "batteries plus bulbs" store and they said it's not necessary to use a converter, but how do you explain the FM TOWNS II HR powering off by itself?

 

completely the other way around :/

 

Bad power supply most likely bad capacitors. Have it looked at.

the psu will run in the 100v range fine ie: 100/110/120v it's within the 20% tolerance.

 

Just like any PC, turning itself off is indicative of a fault. It's probably doing it for safety reasons. It could be the PSU, but it could also be something telling the motherboard to shut down. Heat sensor, fan sensor, bad caps etc.

 

Hope no one blew up anything because of my post. I fixed it.

 

If a Nintendo Color TV Game system is designed for an Output of 9 DC, would, let's say, a 10V DC Famicom or Sega Genesis/Master System adapter be ok to use with it?