Powering OI from battery?

Technical Control System
#1

We’re currently finishing our T-shirt launching robot, and would like the OI to be portable. We’re using the 2004 control system.

Basically, I need a way to power the OI with a robot battery. Has anyone done this? If not, does anyone know how this might be done?

Possible methods (in my mind):

  1. Find documentation stating the OI can be run off a battery (not regulated 12v)
  2. Use a DC-DC converter ($$$:()
  3. Wire up an additional robot controller, and only connect the power lines (again, I’d need documentation.)

Thank you.

#2

I don’t know if you guys have VEX controllers and batteries around, but that’s how we’re running our t-shirt shooter. We use FRC gearboxes, victors, spikes, compressors, and solenoids with the VEX controller, and it’s pretty easy to program.

#3

I’ve run OI’s using an unregulated 12v battery source.
Unregulated isn’t an issue since the OI regulates it down to what it needs internally.

I don’t think I’ve ever run across documentation stating the designed input voltage range though.

We’ve also used a Vex transmitter rechargable as well as just a bunch of 9v batteries.

#4

We purchased an inverter from Andymark for $33.00. It is small, works great and comes set up to connect with a robot battery.

http://www.andymark.biz/am-0626.html

#5

I second this option.

An inverter like that is an awesome thing to have, and is worth it’s weight in gold. When you’re at a competition when you can be away from your pits waiting for a match for an extended period of time, an inverter is a good way to keep your OI charged and up and running. I’ve seen a lot of teams leave the inverter and a batter on their cart and use it exclusively for powering the OI.

Oh, and it’s also good for Demos and stuff too.

#6

Back on 294 when I worked on the control board we would wire in an RC/Vex battery (7.2V Nimh) and a recharging circuit. They’d run for several hours without wall power at least.

#7

I think any way you can use a wireless controller with your t-shirt shooter would be best. If you’re taking this thing to games, crowds, exhibitions, you don’t want it tethered to a controller.
Of course, this is all assuming your t-shirt shooter is on a drivebase. If it’s a platform shooter, then disregard the above.

#8

Thanks for the advice.

I think I/we’ll order that AndyMark inverter. I too agree that it would be generally useful.

Until that gets here, however, I think we’ll just run off unregulated power, for a couple reasons:

  1. We have more OIs if we burn one out
  2. The power brick might not be regulated well anyway (I know that many aren’t)
  3. We need it now.
  4. It worked for AdamHeard.

Thanks for all the help.

#9

Just to be sure, what OI are you talking about? The laptop from last year or some other controller?

#10

I’m talking about the 2004 controller.

#11

You are fine feeding 12 VDC into the 2004 controller. I confirmed that with IFI engineering a long time ago. I can’t remember but it uses a linear regulator similiar to a 78M05 which is rated for up to 35 or so VDC.

Just make yourself a connector cable, confirm with a meter that you wired it up correctly and you can drive a long long time on a standard robot battery.

#12

So it doesn’t care if it’s not regulated? Great!

Thank you.

#13

As noted earlier, the OI has an internal regulator. I would not go higher than 12 volts, however. The WRRF operated these OIs on 12 volts through the competition port for quite a few years with no problems. If you go higher, you may run into power dissipation issues on the internal regulator.

Eugene