Voltage question


 Would a component from Japan that is rated 100 volts be safe to use here on 110-120 volts, without some type of transformer or the like?  TIA  Mike


winoguy17
Would a component from Japan that is rated 100 volts be safe to use here on 110-120 volts,

Safe? That's not the problem. The problem is you will be feeding the piece of equipment at a much higher voltage than the equipment was designed to be operated at. Will it work? Yeah,.... But you will shorten its' life.


General rule is + or - 10% of the manufacturer’s recommended voltage.
100Vac x 10% = 110Vac.

The average residential AC mains voltage in the US is 119Vac - 122Vac. 120Vac nominal probably being the most common.

The cheapest way to reduce the voltage to 100 volts is with a Buck auto-transformer.
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no, get a simple transformer to step 120 down to 100v, they are easy to find. it's about the turntable's motor.

I've had fancy expensive one and inexpensive one, neither hum as was my concern. inexpensive one is both smaller and lighter, easier to find a place for it to go.

you might want to mark the TT cord 100v, so nobody makes a mistake with it in the future.
Perfectly safe. No problem.
What exactly is the kit you are thinking of though??

Lots of newer kit is multi-voltage.
Stepdown converters are affordable or perhaps try using a variac. CD players don't consume much power so should be pretty easy to run off a variac.
Check the back of the CD player for input voltage.
As Eric says... if the voltage range covers 100 to 120 then no problem.
If it only says 100 volts I wouldn’t even plug it in.
Just to give you all some idea how absurd it is to think a few volts matters, I once ran a lithotripsy machine designed for 240 on 120. For you mathlexic types that's like half the voltage. That's a complex and highly computerized machine that generates shock waves that break kidney stones. Its a lot of power, precision, and an incredible amount of sensitive electronics. More pumps, motors, servos, microprocessors, transformers and high voltage power supplies (in excess of 60kV) than you can shake a stick at. You would think the thing wouldn't even run, or at least would throw error codes, or work but weakly, anything but what happened, which was nothing. Worked absolutely fine. Didn't even know about the voltage until after the fact.

The disconnect from reality, misinformation, and nervous nonsense surrounding all things electrical is simply off the charts.
Just to give you all some idea how absurd it is to think a few volts matters, I once ran a lithotripsy machine designed for 240 on 120. For you mathlexic types that's like half the voltage. That's a complex and highly computerized machine that generates shock waves that break kidney stones. Its a lot of power, precision, and an incredible amount of sensitive electronics. More pumps, motors, servos, microprocessors, transformers and high voltage power supplies (in excess of 60kV) than you can shake a stick at. You would think the thing wouldn't even run, or at least would throw error codes, or work but weakly, anything but what happened, which was nothing. Worked absolutely fine. Didn't even know about the voltage until after the fact.
The disconnect from reality, misinformation, and nervous nonsense surrounding all things electrical is simply off the charts.

@mc
Well said !!!
 As stated in the OP ,its rated 100v.   So far Ive been told:
1. Need a transformer2. Its fine.3. Dont even plug it in.Appreciate your thoughts. If I do pursue this I would probably look into stepping down the voltage. Where is a good place to look for one?  Thanks again.
winoguy17 OP655 posts

03-02-2020
6:28am

As stated in the OP ,its rated 100v.


If I do pursue this I would probably look into stepping down the voltage. Where is a good place to look for one? Thanks again.

I would first check the AC mains voltage with a volt meter at the wall outlet to see what you have. Check it a few times through the day to get an average reading, measurement. Does it average 120V - 123V? Does it average 118V - 120V? Or maybe 119V - 121Vac?

Be careful of buying a cheap so called voltage converter that says to size the unit at two times or more the rated load of the item that will be plugged into it. You might want to also read the customer reviews on the unit if there are any. I have a feeling the manufacturer of the really cheap so called voltage converters are under sizing the wire gauge used in the winding/s.

Here is a step down transformer manufacturer I found, searching the Agon archives, from an Agon member that posted on a thread. I used his link and found these two transformers that should meet your AC mains voltage. The smallest wattage transformer I could find is 300 watt.

https://acupwr.com/collections/japan-to-usa-transformer-converter-use-100-volt-appliances-in-110-vol...

This Link is from a retail seller, I believe.
https://www.bhphotovideo.com/c/product/964851-REG/acupwr_ajd_300_ctoc_japan_to.html.
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easy, amazon prime, $30. have it tomorrow.

https://www.amazon.com/VCT-VT-200J-Japanese-Transformer-Converts/dp/B081TLK87S/ref=asc_df_B004S2COIC/?tag=hyprod-20&linkCode=df0&hvadid=226131567976&hvpos=&hvnetw=g&hvrand=15901971708719460343&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9003512&hvtargid=pla-390921810426&th=1

they have several, they vary according to the amount of watts the device draws. Voltage must match, and watts simply have to be enough for the device(s) it feeds, CD player is not gonna need more than this 100 watt version..

A device will only draw what it needs, like a 60 watt bulb draws less from a line rated for much much more.

Volts are volts, i.e. Apple's 5 volt chargers. the amperage is low or high (amperage is relative to watts), so they keep raising the needed amperage so you need to keep on buying new adapters. And, they keep changing the connector types, the ........


Stepping down the voltage is the correct solution. Running it at 120 volts can cause problems... for example if a secondary voltage somewhere inside the unit is, say, 34 volts and there are 35 volt capacitors, then 120 volts on the primary will increase the secondary voltage above the rating of the capacitors and...poof. So unless you are dead sure about the voltage ratings of the parts inside, step down the voltage to where it is supposed to be. Simple physics, not misinformation.
If it has a switch mode power supply, odds are it will be okay at 120/60Hz, though if truly designed for 100V only (rare) it could have issues with component tolerances and fail early.  If it has a linear supply, you could overheat things.
w.r.t. this post below, odds are it was built with universal 100-240VAC switch mode power suppl(ies). It is sensitive, but would likely use off the shelf supplies.

millercarbon3,254 posts03-02-2020 3:02amJust to give you all some idea how absurd it is to think a few volts matters, I once ran a lithotripsy machine designed for 240 on 120. For you mathlexic types that's like half the voltage. That's a complex and highly computerized machine that generates shock waves that break kidney stones. Its a lot of power, precision, and an incredible amount of sensitive electronics. More pumps, motors, servos, microprocessors, transformers and high voltage power supplies (in excess of 60kV) than you can shake a stick at. You would think the thing wouldn't even run, or at least would throw error codes, or work but weakly, anything but what happened, which was nothing. Worked absolutely fine. Didn't even know about the voltage until after the fact.

The disconnect from reality, misinformation, and nervous nonsense surrounding all things electrical is simply off the charts.

Get the step-down transformer unless you have a smart power supply.

The way to tell is to read the requirements right off the device. If it says 100V and not 100-240V or something like that, you need the STD.
Just to throw this out there.
I once ignored the 100v only and ran a DVD player on my 120v line thinking  it would be fine only 20% over volt.
Sure it worked just fine... For about 2 months when it then went up in a big poof of smoke.
Sure it was not major but I could not be bothered to even investigate.
Lesson learned I use stepdown on both my Japanese 100v TT now.
👍👍👍 Ymmv.
you need the STD
Nope
Don't need any STD thanks.
You keep them to yourself please!
thanks everyone for your input. If I do pursue this I will definitely step down the voltage, hopefully avoiding STD  s....
@winoguy17 

Just to be clear, you need to select a step down transformer (SDT) that best matches your wall AC mains voltage. Again you need to check your AC mains voltage at the wall outlet.
 
If your mains voltage average is 120Vac or less then a 115-120Vac to 100V SDT would average an output closest to 100Vac.     
Example  
  https://www.bhphotovideo.com/c/product/964851-REG/acupwr_ajd_300_ctoc_japan_to.html.      
If the wall outlet mains voltage is higher than 120V, say 122V, then a 115-120Vac to 100Vac SDT would not be a good choice, imo.  The output voltage of the SDT would be higher than 100Vac.

 
 If the mains voltage averages higher than 120V, say 122V, maybe 123V, then the  125Vac to 100Vac SDT would be a better choice. The average output voltage of the SDT would be closer to 100Vac.      
 Example         
https://acupwr.com/collections/japan-to-usa-transformer-converter-use-100-volt-appliances-in-110-vol...  


If you can find a SDT that is rated at *120Vac* to 100Vac that would be fine for a mains voltage that ranges from 118Vac - 122Vac.  
If the mains voltage is below 120Vac then the SDT would output slightly below 100Vac. With a mains voltage above 120V the SDT output voltage would be slightly above 100Vac.

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