8.4 volts to 12 volts?

[rootbeerben3]

I have this screen that is not the psone screen and needs 500 milliamps at 12 volts. my battery pack is 8.4 volts 4200mah. is there a circuit i can build to boost the voltage?

video of screen: http://www.youtube.com/watch?v=WsWIJRgabco" onclick="window.open(this.href);return false;

[gannon]

I'd open up the screen and search for internal regulators, it might work off of less voltage, never know.

[lucidPerspective]

Stepping up the voltage from 8.4v to 12v will burn up(non-literally) your mAh about 30%-40% faster.

your better off getting these: 12V 3500mAh Lithium Battery Pack With Auto Charger

They're about the same price as that step up converter. and you can use them at 12v for your screen and then step them down with a switching regulator to get the 3.3v and 7.4v for your N64. stepping down 12v to the lower voltages will then burn up mAh 50% slower. so from that 12v 3500mAh battery, you can think of it as the equivalent of a 6000mAh at 3.3v - and 4500mAh at 7.4v.

DISCLAIMER: Those random mAh values are random estimates to help put across my point

did that make any sense at all I hope you get it

[rootbeerben3]

thanks, im going to look for an interal regulater. it seems unlikely that the lcd really needs 12 volts. if i cant find any, then im going to get those batterys. thanks for all the help.

[snowpenguin]

Be wary of that battery, there have been MANY MANY MANY bad hong kong batteries that are over-rated on ebay. I personally wouldn't buy it. It looks too small, and it probably is actually a 7.4v battery stepped up if anything, considering 12v is not a voltage that can come natively out of a standard lithium cell.

Try putting a lower voltage directly into your screen. often that works.

[lucidPerspective]

I've opened up the batteries I recommended him, and it contains 3 x 4.2v cells. I was recommended them by a fellow modder, and they're the ones I've got for my portable. I haven't done extensive testing with them yet, but the build quality is fantastic, the casing is well built and sturdy, the soldering inside is very tidy. being afraid of spending half the price on cells from China, is kind of silly.. sure there are some really horrible cheap batteries out there. but more often than not the same cells you'd find in a top shelf product are made in china.

at the price those batteries are, and the build quality of them, I'd say they're a good one to try out. and hey, if they don't work out as well as you hope your not out of pocket much.

Also I'm not sure if.. "Try putting a lower voltage directly into your screen. often that works" ..is very good advice -.- it's safer than putting a random voltage too high in. but under-voltaging equipment can still damage it. it's best to look up chip numbers online and see what the regulators in it can take.