I bought a PSP car charger (third party, pelican brand, $9.99) and it works wonderfully. It plugs right into the AC adapter dongle thing, since it has the same plug as the AC adapter. It's rated at 5v 2A. No screen flickering to speak of. Used it for 3-4 hours during a road trip, full screen brightness, with microdrive in use, and it charged the x50v to full while in use.
I highly recommend it.
oh, sheeesshhh...
and i bought one of those wall chargers (for USB) rated for the Axim x50v - god!!! i should have just gotten the PSP wall charger (USB)...
I am a newbie...I am really confused "what to do " and "Not to do"..can anybody help me with bullet points..so that i don't come to my own conclusions after reading this thread (anyway i will doing that to understand things)..
further i have ordered the belkin cable syn kit with auto adapter only from dell site (not the own with power) ..i am also getting the USB cradle along with the product...which one and when i have to use & not to be used..
we know that power is from voltage, right? which means that for a constant R, if the voltage is lower, say 5v, the current I1=5v/R according to Ohm's Law; if the voltage is gigher, 5.4v, the current should be increased, I2=5.4/R. So, if we use wall charger with 5.4v input, the charging time will be shorter, on the other hand, the chaging time will be longer if we use use syns/charger cable.
The current only depends on the load, which is the resistance. you guys' assumption is that the output (of the charger) is a constant(voltage times current), as is definitely wrong.
The current is determined by the load---resistance
give you guys example.
USb pin assignment is +5v,-D,+D,G(groud). If we connect 10Ohm resistance between +5V and G, the current in the loop is 0.5A; if the resistance is 100Ohm, the current should be 0.05A; how about 10000Ohm, the current is decreased to 0.0005A;
IF the resistance is infinite, which means "open", then there is no current.
what I'm saying that the current is determined by the load--resistance.
if the voltage is gigher, 5.4v, the current should be increased, I2=5.4/R. So, if we use wall charger with 5.4v input, the charging time will be shorter, on the other hand, the chaging time will be longer if we use use syns/charger cable.
Sure about that? If the voltage is lower, doesn't it just mean the amount of current needed will increase? Instead of needing, just for example, 800ma at 5.4v to charge a battery (~4.3w), you would need 860ma at 5v(~4.3w), to charge at the same rate, right?
Volts*Amps=Watts
Or are you just giving an example of a misconception?
Originally Posted by md_blueolds
The current only depends on the load, which is the resistance. you guys' assumption is that the output (of the charger) is a constant(voltage times current), as is definitely wrong.
good luck.
I don't believe anyone suggested that the 2amps of a charger is being "pushed" through the device. Just that the 2amps is there and "available" if the device is both being charged, and is being used, which increases the current draw.
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Newton 130 > Palm III > Palm V > Visor Dlx > Visor Prism > Tungsten|C > Axim x50v
md_blueolds you have quoted ohms law, but failed to take account of how NiMH batteries will be charged in an x50v or other similar products.
A NiMH battery has an internal resistance of ~ 0.2 to 0.3 ohm
If you stuck 5 volt across a totally flat battery you would draw about 25A (shortly after this the battery would probably explode!).
The x50v controls the charge current, the current will be intially high, falling as the battery reaches 100%. As well as charging the battery the x50v is also using current to operate, so if the battery is charging at say 500mA and the x50v is using 600mA then you would be looking at approx 1.1A intitially being required to charge and run the x50v.
The values given are guesses on the sort of power requirements the x50v needs, but I guess they will be pretty close.
you are right. Charging battery is quite different from other "pure resistance" products, Since in this electric loop, this are two power sources, and one is the battery with a changing resistance. If the there is no charging control, any "pure btteries" could explode or overheat, because the initial current takes the highest value of the entire charging process (the root cause is the resistance is very low). Some small products have current control circuit inside, others give us a "special charger" to control the charging current.
So I think it is safe using USB sync cable to charge Axim, unless someone charges his Axim using 50V source.
md_blueolds, I'm not sure what point you are trying to make. The Ax has a voltage limiter that blocks power above about 6v. Not sure it would protect at 50V, but it does block a pure 6v power supply. Also, it still remains that the Axim draws close to 1,000 mA to charge and run with a 1100mah battery below about 60% charge. It takes about 400 mA just to run, with screen brightness set up high and CPU on high. The USB port is only rated at 500 mA, so Dell chose to have two charging circuits. One is current limited to 500 mA, so you can either run or charge but not both, the other is not current limited and can run close to 2A if you have a fully dead 2200 mAh battery and run the Ax wide open at the same time. It's safe to use a USB cable for the Ax, it's got protection, but if you have one that crosses those two charging circuits and bypasses the current limiters on a USB port that also doesn't have current limiters, you get a fried USB port, maybe a dead MoBo.
I'm pretty confused here. I guess all I need to know is if it will hurt my x50v if I use a Belkin usb sync cable with a Palm Tungsten E car charging kit. Sorry to be so clueless!
The Palm Tungsten probably needs a lot less power than the x50v so without knowing the charging kit I would say it wouldn't work correctly.
In the short term it probably won't damage the x50v, in the longer term my gut feeling is it will stress components and probably reduce the life expectancy of the battery.
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Maybe, you guys are wrong!
