Just bought a pc engine duo r from Japan

[SignOfZeta]

Two things will cause the power supply to blow a fuse in the system:

The voltage is too high
You plugged it in backwards

I agree that the latter is most likely. Those concentric power plugs have an inside and an outside. One is the ground and one is + and there is no consistency between devices. If you flip them the best you can get is nothing, it gets worse from there.

If you're using one of these supplies than can flow 6x the current of the OEM then I wouldn't be surprised if it did even more damage than just plugging the OEM equivalent in backwards.

[Projekt Pat]

as I said it was a sega model 1 power brick ac adapter. I don't understand how it could be plugged in wrong.


Anyway are you saying that I shouldn't use the 12v 5a supply on the duo r

[mickcris]

Not sure what would have caused the Sega cd fuse to blow as that should have been the right supply.

Just get one of these as it's it's known to work with the duo-r.  That way there is no question as to hurting your system
http://www.ebay.com/itm/232205410083

[Pokun]

as I said it was a sega model 1 power brick ac adapter. I don't understand how it could be plugged in wrong.


Anyway are you saying that I shouldn't use the 12v 5a supply on the duo r

There are five main things you should look for when it comes to AC-DC adapters:

Input Voltage: This should match the AC current in your wall outlet in your country. Japan have 100 V, AC.

Output Voltage: This should match what the machine expects. The Duo R expects 9 V, DC (as written on the console near the power plug port). If it's lower it might not be stable, and if higher it may break the system (or blow a fuse if it has one). The voltage regulator in the machine may have some tolerance though so it might be able to take +/- some volts.

Output Current: This doesn't have to match, it just needs to be enough for what the system requires. If you are using lots of things that draws more power, like a multitap + 5 pads, Everdrive etc, you might need a higher current. The original Duo R adapter outputs 1000 mA (i.e. 1 A) so make sure your adapter outputs around that value, or a litte more.

Polarity: Either center negative or center positive. DC power is polar so this must match what the machine expects. Duo R expects center positive (again written on the console). Center positive means the inner of the barrel of the plug is positive and the outer barrel is negative. If this is wrong the system may be damaged or a fuse blows (unless it has diodes that prevents that).

Code: [Select]

+ ---(--- - Center Negative Symbol
- ---(--- + Center Positive SymbolSome unversal AC adapters have a switchable plug so you can switch between the two polarities. The stock adapters that comes with consoles usually cannot do this though so there is no way you can insert them wrongly. If it blew bacause of this, it just means you used the wrong adapter for the system.

Barrel Size: Of course the barrel plug has to fit your machine.


A higher voltage shouldn't help with CD-R discs I think. Maybe a higher current may do though. I'm using the original Duo R adapter "PAD-129" and I can play uisng HuCards, CDs, CD-Rs, Everdrive, Multitap (haven't tried 5 pads + Everdrive though) etc with no problems.
If you measure an AC adapter you have to measure it under load or it will give you the wrong values.

If you have problems with the original adapter it is probably because it has degraded over time. Get a new quality AC-DC adapter that fulfills the requirements of the system in that case.

[SignOfZeta]

Yes to all that.

Now I want to study power consumption versus CD-R/legit. I've never been a fan of the idea that CD-Rs ruin a system but if higher current draw can be measured then there would finally be some evidence to that theory.

However, from testing I've done in the past I seem to remember that peak current draw on a Duo occurs as the laser sled moves long distances, not from just the laser itself. I'm pretty sure it won't prove much but it would be cool to see.

[SamIAm]

Output Voltage: This should match what the machine expects. The Duo R expects 9 V, DC (as written on the console near the power plug port). If it's lower it might not be stable, and if higher it may break the system (or blow a fuse if it has one). The voltage regulator in the machine may have some tolerance though so it might be able to take +/- some volts.

The kind of regulators that these systems use (usually 78xx) can take any higher voltage and turn it into whatever standard it's designed to output, but not lower voltages.

Also, the greater the excess voltage, the hotter the regulator will run, and it will reach a breakdown point eventually. I'm not surprised that 12V works fine for a Duo "expecting" 9V, but I bet that 20V could cause trouble. I think the 7805 is rated for 24V maximum, but it can't handle very much current draw at that level without getting really hot.

[Slypty]

If you use the original Adapter, the output will be more in North America than in Japan due to the Voltage differences from the outlets.  For instance, if you have the original Japanese Supply which outputs 9VDC, if you plug it in to a wall here it will actually output something like 14VDC.  The reason is that there is no step down converter installed to adjust for the output from our outlets.

  Although you can still use the original Supply, it's better to find something from here if you want to be accurate with how much you give your Duo.

[MNKyDeth]

Just so everyone is aware the US TurboDuo adapter outputs exactly the same as the PC Engine Duo adapter.

So when they released the US TurboDuo they made absolutely no changes to the adapter internally for the differences in voltages.

[Pokun]

Output Voltage: This should match what the machine expects. The Duo R expects 9 V, DC (as written on the console near the power plug port). If it's lower it might not be stable, and if higher it may break the system (or blow a fuse if it has one). The voltage regulator in the machine may have some tolerance though so it might be able to take +/- some volts.

The kind of regulators that these systems use (usually 78xx) can take any higher voltage and turn it into whatever standard it's designed to output, but not lower voltages.

Also, the greater the excess voltage, the hotter the regulator will run, and it will reach a breakdown point eventually. I'm not surprised that 12V works fine for a Duo "expecting" 9V, but I bet that 20V could cause trouble. I think the 7805 is rated for 24V maximum, but it can't handle very much current draw at that level without getting really hot.

Yes, I'm no engineer, but from what I understand, you also need to think about other factors like heatsinks and how it is used with the console. The 7805 voltage regulator is used in about all of the video game systems from NEC/Hudson, Nintendo and Sega of the era, but still they are often rated slightly differently (polarity also often varies between consoles). I think it's best to stay close to what NEC rated their consoles to.

If you need more power, you increase current instead of voltage.
Voltage (in volt, V) * Current (in ampere, A) = Power (in watt, W or voltampere, VA)

If you use the original Adapter, the output will be more in North America than in Japan due to the Voltage differences from the outlets.  For instance, if you have the original Japanese Supply which outputs 9VDC, if you plug it in to a wall here it will actually output something like 14VDC.  The reason is that there is no step down converter installed to adjust for the output from our outlets.

  Although you can still use the original Supply, it's better to find something from here if you want to be accurate with how much you give your Duo.

Yes, I think North American wall outlets are using something like 110-120 V while Japan is 100 V. Many Americans doesn't seem to care about using a step-down converter either.
I'm in Sweden (230 V) so I need to use a step-down when I'm using the stock adapter or I'll fry my PC Engine.

[SignOfZeta]

If you use the original Adapter, the output will be more in North America than in Japan due to the Voltage differences from the outlets.  For instance, if you have the original Japanese Supply which outputs 9VDC, if you plug it in to a wall here it will actually output something like 14VDC.  The reason is that there is no step down converter installed to adjust for the output from our outlets.

  Although you can still use the original Supply, it's better to find something from here if you want to be accurate with how much you give your Duo.

I don't think it's anything like 9V versus 14. That would be a increase of %44 for only a %10-20 bump in VAC.

[Slypty]

I'm not sure the exact ratio measurement, but most of my Famicom AC Adapters I get output around 15-18VDC, which is a big difference.. sounds odd but it is pretty consistent.

[thesteve]

on the DUO-R the sega geni2 plug works, the geni1 plug wont fit in the hole
the polarity and voltage is close enough to work fine
if its blowing fuses, you have a short
it could be a bad regulator, shorted chip, or solder bridge
whatever it is, odds are you can find it with an ohm meter across the duo power  traces (with unit unplugged)