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

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

Post by Archive » June 26th, 2019, 7:56 pm

posted by MonkeyBoyJoey on Sep 4, 2015:

android34 said:






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?

I say go for the 9V versions of the Sega Genesis Model 1 PSU (MK-1602). That outputs 9V at 1.2A. The polarity is center-pin negative (+)------(O------(-) so make sure the Color TV Game accepts that. If it is center pin positive, you will need a different PSU or you will have to change the polarity of the MK-1602.
 

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

Post by Archive » June 26th, 2019, 7:56 pm

posted by android34 on Sep 5, 2015:

MonkeyBoyJoey said:






I say go for the 9V versions of the Sega Genesis Model 1 PSU (MK-1602). That outputs 9V at 1.2A. The polarity is center-pin negative (+)------(O------(-) so make sure the Color TV Game accepts that. If it is center pin positive, you will need a different PSU or you will have to change the polarity of the MK-1602.

Thank you. I appreciate the response. One more question, if you might happen to know. I have a Sega SG-1000, which has a Japanese 100V AC 9V DC adapter. I am able to run it, and I am also able to use a Genesis/Master System power supply with it just fine. I have a step up/down 100V/120V transformer. I wanted to run the Japanese 100V power supply through the transformer to be on the safe side. If something were to happen to that original SG-1000 adapter, and all I had was the 120V AC 9V DC adapter, would I be able to plug that into the 100V slot of the transformer as well, or would that not really matter because the power supply is a 120V? I figured it would just dumb it down to 100 volts through the transformer, but I wasn't sure. I'd rather only have 100 volts coming in to the power supply, if I can. I was also thinking of trying one of those 100V-230V AC 9V DC adapters to have as a backup for the Japanese stuff. If I do end up getting one of those, would it still be a good idea to run it through that 100V step up transformer, or would that not be necessary? I appreciate the help.
 

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

Post by Archive » June 26th, 2019, 7:56 pm

posted by MonkeyBoyJoey on Sep 5, 2015:

android34 said:






Thank you. I appreciate the response. One more question, if you might happen to know. I have a Sega SG-1000, which has a Japanese 100V AC 9V DC adapter. I am able to run it, and I am also able to use a Genesis/Master System power supply with it just fine. I have a step up/down 100V/120V transformer. I wanted to run the Japanese 100V power supply through the transformer to be on the safe side. If something were to happen to that original SG-1000 adapter, and all I had was the 120V AC 9V DC adapter, would I be able to plug that into the 100V slot of the transformer as well, or would that not really matter because the power supply is a 120V? I figured it would just dumb it down to 100 volts through the transformer, but I wasn't sure. I'd rather only have 100 volts coming in to the power supply, if I can. I was also thinking of trying one of those 100V-230V AC 9V DC adapters to have as a backup for the Japanese stuff. If I do end up getting one of those, would it still be a good idea to run it through that 100V step up transformer, or would that not be necessary? I appreciate the help.

If the Sega Genesis/Master System psu works fine, use that in the wall outlet instead of a transformer and the original Japanese psu.

If the original ends up dying when using a transformer, don't plug the American psu into the transformer's 100V outlet. You could either underpower it or damage it, which might cause a fire.

Not sure about those universal psus but if they are the correct rating and polarity, they should work fine.
 

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

Post by Archive » June 26th, 2019, 7:56 pm

posted by wilykat on Sep 5, 2015:

Nearly all of the consoles from 80's and many from 90's are designed with 5v internal regulator so 10v will be fine. Observe polarity though. If it says center positive, the adapter must also have center positive. A few consoles like NES used AC rather than DC and will be fine with DC, any polarity.

AFAIK Colecovision is the only exception to the classic console's 5v rule, they used 12v for the RAM chips.
 

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

Post by Archive » June 26th, 2019, 7:56 pm

posted by android34 on Sep 5, 2015:

wilykat said:






Nearly all of the consoles from 80's and many from 90's are designed with 5v internal regulator so 10v will be fine. Observe polarity though. If it says center positive, the adapter must also have center positive. A few consoles like NES used AC rather than DC and will be fine with DC, any polarity.

AFAIK Colecovision is the only exception to the classic console's 5v rule, they used 12v for the RAM chips.

How do you check the polarity on the ac adapters and the systems themselves? I'm getting an old Nintendo Color TV Game Block Kuzushi without a power supply, but the specs for it are the same as the SG-1000's original power supply.
 

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

Post by Archive » June 26th, 2019, 7:56 pm

posted by android34 on Sep 5, 2015:

MonkeyBoyJoey said:






If the Sega Genesis/Master System psu works fine, use that in the wall outlet instead of a transformer and the original Japanese psu.

If the original ends up dying when using a transformer, don't plug the American psu into the transformer's 100V outlet. You could either underpower it or damage it, which might cause a fire.

Not sure about those universal psus but if they are the correct rating and polarity, they should work fine.

I wasn't sure if plugging a 100V Japanese power supply into the wall was not good, since the US is 120V. I have read that people like to use the step down transformer when using the Japanese power supplies on the Japanese systems in the US.
 

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

Post by Archive » June 26th, 2019, 7:56 pm

posted by wilykat on Sep 5, 2015:

android34 said:






How do you check the polarity on the ac adapters and the systems themselves? I'm getting an old Nintendo Color TV Game Block Kuzushi without a power supply, but the specs for it are the same as the SG-1000's original power supply.

Generally it's marked somewhere that looks like picture below:
Image

If it's not marked, and you can open the system take a picture of the power circuit and us experts can try to figure out what it uses. Unless someone has the same console and can tell us the polarity?
 

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

Post by Archive » June 26th, 2019, 7:56 pm

posted by Lum on Sep 5, 2015:

android34 said:






I wasn't sure if plugging a 100V Japanese power supply into the wall was not good, since the US is 120V. I have read that people like to use the step down transformer when using the Japanese power supplies on the Japanese systems in the US.

Consensus on 100V devices in the US is mixed, if mainly positive, but there's little point in taking unnecessary risks.
When a console has an official US equivalent from the original manufacturer then it's best to use it.
 

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

Post by Archive » June 26th, 2019, 7:56 pm

posted by APE on Sep 5, 2015:

wilykat said:






Nearly all of the consoles from 80's and many from 90's are designed with 5v internal regulator so 10v will be fine. Observe polarity though. If it says center positive, the adapter must also have center positive. A few consoles like NES used AC rather than DC and will be fine with DC, any polarity.

AFAIK Colecovision is the only exception to the classic console's 5v rule, they used 12v for the RAM chips.

5v, 12v, and -12v IIRC. You can bypass the need for -12v by installing replacement RAM chips which is great because the Colecovision power brick is hard to come by and massive. I'd rather use a smaller switching supply or flat out internalize it.




android34 said:






How do you check the polarity on the ac adapters and the systems themselves? I'm getting an old Nintendo Color TV Game Block Kuzushi without a power supply, but the specs for it are the same as the SG-1000's original power supply.

Use a multimeter. If you're hardcore into retro gaming you'll want to pick one up. They're relatively inexpensive for a starter model (voltage, resistance, continuity) and you'll find it very useful with batteries.
 

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