J720's Enemy~NEC MC/HC 300HC

The statement about sizes and weights is always true - regarding the type of the adapter. The problem is that you never know it was really designed for such a range of input voltages. There are several design issues regarding safety, beak-through voltage...

I think there's an easier and cheaper way. What you need to know is the following:

a) output voltage and nominal current (the least usually, in case of a HPC, shall not be a problem)
b) is the output stabilized (in case of switching adapters always stabilized) or not
c) polarity and/or pin diagram on power connector

You can buy then a similar power supply (Conrad...) and use proper power connector and polarity. In such case, you only need to borrow a 220/110 converter to find out what the correct voltage is. In case of your friend you even don't! If she successfully used it for some time, you can take a risk to connect it once again to find out the voltage. Anyway, better with the converter - to ckeck if the voltge changes, to be sure it is about a switching power supply. She might just be lucky using a normal transformer thet the HPC did no go on fire...

This question baffles me sometimes too. My MobilePro AC adapter that came with the unit is rated at 110v - 240v AC (The UK is at 240v AC with 3 pin plugs I do have 2 converters for that,), however, the manual lists the PSU at 110v. So which one is correct? 110 or 240?

The other thing is that I also considered using a switching mode power supply, but the one I have is rated at 1.96A @ 7V DC, I need one that is 1A at 9V input, even though the unit is rated at 7.2v DC @ 36W...... Confusing?

vjurkas, thanks for the information again clears up a lot.

a) 9V, 900 mA
b) how can i find out about it ?
c) will be the problem, it is a japanese plug, and maybe special. probably i wouldn't be able to find this in hungary, so i would have to solder and i won't take the risk, someone else has successfully bricked his sigmarion in this way.

don't care about the manual...... it is 110-240V, my 900's adapter is the same, 100-240, though its output is 12V. (900 is different from the 7xx in this respect)

AFAIK, the MP 7xx can take either 7.5V or 9V. but ask Rich, he'll know for sure

but as you already have a switching mode supply (or isn't 100-240 considered switching? then i misunderstood )

hm, i don't understand, why 36W?

110 - 240V is the nominal input voltage range for the adapter. So, the manufacturer guarantees proper performans until inside this range. I cannot tell you why the manual lists it at 110V. If a sticker on the adapter says 110-240V, it probably is the correct information. Try to check for the device on the net.

I don't understand. Which unit is rated 7,2V/36W? The one that is supposed to use 1A/9V?

If you need 1A/9V and posess 1,96A/7V it might work. The electronic devices usually have additional internal PS which takes care about non-stabilised input voltage.

b) Use a voltmeter.
c) If it was the only chance, I would have simply cut the wire and solder it to the new PS. Carefully check the polarity. I hope that the number of wires is not greater than 2

Maybe we should move to the HW forum

thanks again

yes, it would be a good idea to move to HW as i still have some silly questions or maybe i'll send them in a PM

Probbably better on the forum. Just PM me if it is moved somewhere else.

Now this site is on emergency bandwidth. So i have uploaded some files to my own album in a Chinese website.

They are all 2048*1536. One is about the ports. Please check them out.

http://photo.163.com/openalbum.php?username=iamjoechow

THe official charger says "Produced by NEC CustsomTechnica Ltd. Kinda of weird and an unusual NEC name.

thanks.. looking at them soon