Perhaps some modifications to sooth your USB charging woes?

[Childofthehorn]

Hello There,

I bought this tablet the past weekend after being on rainchecks and searching everywhere.

The USB charging does NOT work, it simply cannot work. They do not have the correct hardware in there to boost the 5V into 9V.

But AHA! we can (albeit with varied efficiency). We have room inside the back of this thing, esp with the non-pop board back there.

There are a couple of ways.

1. Put a USB charging circuit in there to boost the power to 9V at ~270-380ma
2. Create a USB to Charging bit adapter

There are a few ways to do it as well....

1. Buy a USB to 9V simple small adapter (I just bought a Zip-Linq USB-9V adapter)

2. Buy a USB 9V charger cable (saw one here, looks correct size-wize )

3. Find an old Lan card from a busted computer and build your own (these are called flyback 5v to 9V converters) Look at These and These


I chose to do #1 because I also wanted the slim surface mount USB female port because I plan to put that in place of the HDMI port that does not exist. Better to have a good USB host for keyboards and such eh? Also, I want to put a Palm touchstone inductive charger in the back because I have a bunch of the Palm docks that I am currently using with my modified Evo. Inductive Charging= Win. I know that the rate is slower, but that is only assuming that you are using standard 500ma ports. Even still, 280ma should keep this thing alive and a little extra.

Still you can add USB charging for ~$13 shipped (macmall, amazon, or for free with the old crap in your house).

Have Fun you hackers!

 

[tipstir]

Another glitch on the unit is when it charges the red amber inner lite is alway red never turns green. If you take the USB to USB AC connector it will charge. PC USB if crowded with mouse, keyboard, digital camera doesn't seem to charge off the USB 2, but old USB 1.1 it seems to charge. I haven't tested the charging in the Car yet? Since I did buy universal USB to card charger for my GPS.

 

[xaueious]

Interesting...

I do hope the USB port supplies enough power to let you do something like this

 

[Childofthehorn]

They PSU should really supply enough because that 280-380ma (depending on chip...I did the 380ma) is based off of it running on 500ma USB ports and does not include the powered hubs or AC chargers.

The item should be here in a week and I cannot wait to throw it in there. I have TONS of microUSB and this would be ideal. I am also planning on putting in a simple switch that will turn the converter on or off. This is because I want to put a proper USB port for USB host and want to negate any potential issues with isolation or it drawing current away from the 5V device when unwanted. It is also of battery concern when the device is on.

I have no way at looking at the software implementation here, so I am just going to play it safe.

Also, for those of you looking at the ripple current, it doesn't matter because it is recharging a battery with a built in trickle charge (that bulge at the top of the battery is a tiny circuit board - almost all mobile devices have them now built into their batteries and all modern iPods have them).

 

[ichan8888]

I have ordered the USB 9V charger cable, I hope it works cause it is driving me mad. I purchased my iRobot from a shop called Leader Peripheral in Golden Computer Arcade in Hong Kong, it worked perfected well for 2 weeks when I got home then the adapter just turned its toes up and refused to charge anymore. My unit still got about 30% battery so I can still boot it up so I can assume that it is not the battery. I emailed the merchant twice over the last couple of weeks, no reply, I finally rang them and was told I am responsible for the postage both ways to send the unit back to be fixed or replaced. These units are for sale on eBay and all of them offer warranty that if the damned thing breaks in the first 2 months and you send it back, they will take care of the postage return. The moral of this story is you are better off buying online from eBay where you are somewhat protected by their rules, buying in Hong Kong or China you are really at their mercy.

 

[kong]

I have ordered the USB 9V charger cable, I hope it works cause it is driving me mad. I purchased my iRobot from a shop called Leader Peripheral in Golden Computer Arcade in Hong Kong, it worked perfected well for 2 weeks when I got home then the adapter just turned its toes up and refused to charge anymore. My unit still got about 30% battery so I can still boot it up so I can assume that it is not the battery. I emailed the merchant twice over the last couple of weeks, no reply, I finally rang them and was told I am responsible for the postage both ways to send the unit back to be fixed or replaced. These units are for sale on eBay and all of them offer warranty that if the damned thing breaks in the first 2 months and you send it back, they will take care of the postage return. The moral of this story is you are better off buying online from eBay where you are somewhat protected by their rules, buying in Hong Kong or China you are really at their mercy.

Hi, my tablet is an Acer a500 and the charger is bad, is there any way to charge it using the USB...tnx. The battery is now dead and am stuck.