F200 Power Adaptor

[bencoder]

OK, so I bought a 1000mA universal adapter (thats 1000mA at 12v.. its rated for 1400 at 3v)... Its set at 3v, definitely center negative.. I plug it in, the gp2x switches on and I hear the startup sound, but I get the fuzzed up screen, as if I had dead(for the gp2x) batteries.

It works fine with batteries.

If it should work then is it likely that its my adaptor that's broken?
I bought this one: http://www.7dayshop.com/catalog/product_in...ducts_id=101172

Thanks for any help

 

[bomberman]

It seems that you are under powered. My official adapter is set at 2A. Some people have reported running low amperage but it appears that may not hold true for every system. I guess all GP2X are not created equal. :rolleyes:

 

[bencoder]

I guess i'll have to send it back

 

[Squidge]

1.4A should definitely be enough to get you to the main menu, I'd say the adaptor is faulty.

 

[bencoder]

1.4A should definitely be enough to get you to the main menu, I'd say the adaptor is faulty.

Thanks for your answer squidge. Could it also be the GP2X that's faulty? Anyone else experienced anything like this?

I'll test the adaptor with my multimeter.

thanks,

Ben

Edit: Ok, I just tested it with no load, and its pushing out 2.2Amps.. that should definitely be enough, so I'm going to have to assume that my gp2x is faulty. OR... is it possible that a slightly too small connector could cause this? it seems to be a little too small for the hole and its very tight to put it on(due to the center pin). Any ideas?

 

[Squidge]

Thanks for your answer squidge. Could it also be the GP2X that's faulty?

It could well be, but unfortunately there's only one way of finding out..

Edit: Ok, I just tested it with no load, and its pushing out 2.2Amps.. that should definitely be enough, so I'm

How did you measure that? Adaptors don't "push out" amps, they only provide as much is needed by the load connected to them (upto there stated maximum).

You might want to connect a load of at least 500mA and test the voltage.

 

[bencoder]

Thanks for your answer squidge. Could it also be the GP2X that's faulty?

It could well be, but unfortunately there's only one way of finding out..

Edit: Ok, I just tested it with no load, and its pushing out 2.2Amps.. that should definitely be enough, so I'm

How did you measure that? Adaptors don't "push out" amps, they only provide as much is needed by the load connected to them (upto there stated maximum).

You might want to connect a load of at least 500mA and test the voltage.



I just put the meter directly onto the pins, pretty bad for the meter but i figure thats the maximum that its going to be able to supply.. ok, so I need at most a 6ohm resistor to test this.. hmm.. i dont have anything that low. I have 4 47ohm resistors i can put in parallel to give me ~ 11ohms... i'll try with that...

OK, its doing 260mA.. about what i'd expect.. difference across it is 3.17v (after almost burning myself on the resistors )

That seems to be ok... Need to find a bigger load to test it properly I guess, but at this point it seems to be the gp2x.

By the way, it works when I have batteries in, i'm trying to find some dead batterys to test it with to see if it just requires batteries to be in there, or if its pulling the extra power needed from the batteries.. unfortunately I seem to have charged all my batteries

 

[gruso]

The only way to measure current flow (amps) is to put your meter in series with the load.

http://hyperphysics.phy-astr.gsu.edu/hbase...ic/movcoil.html

In this case you really should try to test it with the GP2X running. There are two ways to go.

1. Cut one of the cores on the power supply cable (low voltage side ), strip the ends and connect to your ammeter.

2. Separate the cores (without cutting or stripping) and measure with a clamp meter - http://www.meter-man.com.au/300.htm

 

[Squidge]

3. Measure the voltage drop across an appropriate inline resistor (My usual method, as my multimeter only measures amps, and this allows me to measure mA).

 

[gruso]

Ah, of course. I suppose a little maths never killed anyone.

Sincerely,

Your average lazy sparkie

 

[bencoder]

QUOTE

1. Cut one of the cores on the power supply cable (low voltage side ), strip the ends and connect to your ammeter.



I will try this tomorrow I think... well I wont cut any cables cause I might need to return it but I can make my own wire between the power supply and the little dc plug that goes into the gp2x.

Further to my point about the batteries, when i put batteries in and use the adapter it seems to work fine, even if the batteries are at one bar on the indicator, with the power supply plugged in i get a full 3 bars, so I'm probably just going to use it like that if i can't figure this out.

 

[Squidge]

That's weird, as the batteries are disconnected as soon as you connect the main adaptor :blink:

 

[bencoder]

That's weird, as the batteries are disconnected as soon as you connect the main adaptor :blink:

that is very strange!

well assuming these problems are related, if I put the connector in and it doesn't disconnect the batteries, would that cause a problem if the batteries are not there? I don't see why it would personally, disconnecting the batteries should be the same as not having batteries there, unless by "disconnecting" what it actually does is short across them to override them with the power supply but that would kill the batteries if you left them in while also using the power supply, so it can't be that... but I don't know enough about it to be sure.