pic: VEX power from 12v
 

Re: pic: VEX power from 12v
 

im woundering what resistors you had used in this project, my team is wanting to do the same thing, Thanks!

Re: pic: VEX power from 12v
 

Whoa, way to revive an old thread!

The key part is a variable voltage regulator (probably an LM317T), so take a look at the datasheet to find out exactly what resistors you need. The Vex controller needs between 7.2 and 9V. You could also use a straight 9V voltage regulator, although you would probably have to order these instead of getting them from Radio Shack.

Re: pic: VEX power from 12v
 

Plug it into your Digital Sidecar, that's all we did.

Re: pic: VEX power from 12v
 

There were no Digital Sidecars in 2006.

Re: pic: VEX power from 12v
 

the vextrollers do work at 12v. just have to be careful with the amp draw at the higher voltage.

Re: pic: VEX power from 12v
 

The LM317T also really prefers a heat sink for anything more than about 1/2 Amp, and a large capacitor (~10 uF) at the output will help it as well. Again the datasheet is your friend.

Re: pic: VEX power from 12v
 

I made one of these based on the information in this thread and a data sheet from I believe it was TI. I've drawn up a rough sketch of what the circuit looks like and figured I'd share it. Works great for us and outputs 7.2 Volts, just about what the Vex computer would love to have.
Here's the rough schematic I made:

Re: pic: VEX power from 12v
 

http://www.vexrobotics.com/products/.../276-2170.html

At least on the old computer it says that with motors and servos the computer should draw about 62 mA. I have a heatsink on the LM317 on the converter I made but after testing it and reading this bit of information, i think it may be unnecessary.