Powering an external compressor

[austinious]

We are considering pneumatics for the first time, and are considering off the robot compressor. Is there anything in the rules about using inverters to plug the robot in, in the pitt area?

I can't find anything.

I'm also posting this to FIRST.

Thanks

3567

[Mark McLeod]

It has to be powered as if it was on the robot.
So an outside power source cannot be used.
And it must be a robot legal compressor.

R80
...
Off-board compressors must be controlled and powered by the ROBOT.

[austinious]

Yes, but R34 states that
The only legal source of electrical energy for the ROBOT during the competition, the ROBOT battery, is one of the following 12VDC non-spillable lead acid batteries:

when in the pitt, is that considered part of the competition?

[Mark McLeod]

If the air you are storing is for the match, then it's governed by the competition rules.

In any case, no extraneous sources of robot air/power are allowed at competition (and that's the event, not just a single match).

[austinious]

you misunderstand.

My question is to conserve battery power and plug the robot in when in the Pitt using a voltage converter. I totally understand the rules about using the compressor on or off the robot, except for this power issue, can a robot be plugged into the wall when in the pitt for charging the air canisters.

[austinious]

Thanks Frank, I was really asking what other teams did, we have 4 good batteries and two chargers, so it should be fine.

[Tom Line]

Most inexpensive inverters will not be able to supply the high amperage requirements of the robot. Remember: the reason we have to put a breaker in the spike of the compressor is because fuses will blow due to the high start-up current required. Most cheap inverters are fused well below 20 amps. That's not the total load of the robot - you have to include all the other devices onboard that draw power.

[Al Skierkiewicz]

austin,
The start/stall current on most motors on the robot would trip off any power supply you can easily carry around. So if you are only using the power supply to power electronics and not motors, any 12 volt power supply capable of 20 amps should work. If you want to use the compressor too, the stall current on the large compressor is 27 amps and the smaller compressor about 25 as I remember. Run current for either is between 10 and 15 amps in addition to the electronics. My linear ham station power supply with a 25 amp peak could not start an FP motor no load without tripping.

[FrankJ]

R80 Is pretty clear "powered by the robot" & applies to when in the pits.

It is not really a issue unless you are short of batteries. Just charge the tank & put a fresh battery on the robot. Same as you would if the compressor was on the robot.

You would need a 20+ amp power supply to run the robot with the compressor. Batteries are less expensive and more useful.