Power Management Recommendation for driver stations
 

At the 2010 Peachtree Regional the teams that played Saturday afternoon essentially had to play the afternoon on whatever charge existed on their Classmate. It was rough on the classmate battery.

When teams are at the driver station the classmate has to be running on its internal battery only !!

I would STRONGLY suggest that you get a dc-ac inverter, 100 watts or so. You can buy them at Walmart or a truck stop for $ 20 or so. Put an Anderson powerpole connector on it and plug it into a robot battery. Put the battery/invertor combo on your robot cart and it can keep the classmate topped off and ready for your match.

Then as you sit in queue Saturday afternoon you will topping off the classmate and be in great shape with the driver station. When you go to place the DS for the match you just pull the plug on the classmate and go to work.

It will cost less than a second classmate battery and you can use it as a power source for driver stations for public demos and to do a hundred other things.

Re: Power Management Recommendation for driver stations
 

one of the mentors from our team brought a portable laptop charger, and it worked phenomenally!
it was kinda like what you are suggesting, but in a light, conviniently small package. it weighed no more then 3 pounds, and was about the size of a letter envelope, and about a half an inch thick. it powered the laptop for the entire day whenever the laptop was not in the pits, and it still had charge to spare at the end of the day! (it is also re-chargable itself, so its uses are unlimited)
our classmate battery never dropped below green!
it definitely saved our butts in the finals.
I was happy we had it when I walked around and saw red battery indicators on some of the other teams' screens...

If I knew the model number or anything, I would tell you, but I don't.
Maybe Ill ask our mentor at the next meeting, and post it here. the thing was a lifesaver!

EDIT: AND!
we talked to the head ref, and he said that it was legal to keep it plugged in durring a match, so the laptop did not go into power-conserve mode.
It seemed to speed up our camera-image speed a bit.

Re: Power Management Recommendation for driver stations
 

It helps to turn the wifi off.

Re: Power Management Recommendation for driver stations
 

Yeah, our team was feeling a bit of "red" so to speak on Friday afternoon.

We're currently looking forward to doing something to aid in keeping the Classmate alive for matches. What has been said here is great, specifics would be fantastic.

I still wonder why they didn't have a power cable on the alliance station - just to make things a bit less crazy for set up and stuff? Having a DS with a battery is nice, but some days its nice to have a power source.

-Tanner

Re: Power Management Recommendation for driver stations
 

Do you have any specifics on this device? Sounds interesting. I am currently designing/building a similar device. Would there be any interest for this?

Re: Power Management Recommendation for driver stations
 

What we did was just close the classmate after every match, bring it back to the pits and let it charge. Any time we were not on the field, it was charging in the pits. For eliminations, we went to the 3rd match of the semis, and we had plenty of battery left. The key is to leave it on the charger, and to close it after every match (it goes to sleep).

Re: Power Management Recommendation for driver stations
 

I do not know anything about it right now.
now that I think about it, the mentor who it belonged to is going away on a week-long buisiness trip tonight, so I will not know anything about the device for a while :|
I will try and let people know what it is as soon as possible!

the most I could tell you about it now is pretty much that it was a rounded-edged black box with about a 5" cable coming off of it. haha

Re: Power Management Recommendation for driver stations
 

Power was a bit of a problem for us as well. The matches drained power faster than we could build it between matches. By the end of Friday the battery was almost dead. At least emergency charging is available during eliminations.

Make sure you leave your classmate charging overnight at competition. It's the only reason we survived Saturday

Re: Power Management Recommendation for driver stations
 

I'm a big fan of invertors / Anderson connector / robot battery arrangements because it give you a pool of batteries that interchanges with the robots and allows you do do all sorts of things.

Kinda like the military 'one fuel' concept. They have jets, helicopters, tanks, humvees, trucks, and motorcycles that run off the same fuel.

Re: Power Management Recommendation for driver stations
 

I wonder why FIRST couldn't add power cables for the Classmate. I would see it as a very cheap solution. FIRST should get feedback about this because it does seem like a bit of a big problem that you can't compete because the Classmate battery is dead.

Re: Power Management Recommendation for driver stations
 

Inertia - The trucks are loaded and rolling from regional to regional. Getting the solutions configured and shipped out and meeting the trucks at the next regional, implemented and rolled out to the next events I'm sure is an effort. And they are most certainly busy setting up for the CMP.

The cost of implementing the power cable solutions means that something else isn't getting done. It is an economic opportunity cost problem.

Having the battery / invertor combo is great for demos. You can solve two problems at once.

Re: Power Management Recommendation for driver stations
 

We found that to be a HORRIBLE idea. Every time we would close our Classmate, the joysticks would get out of order, and often times it forced us to reboot the entire system.

Much better to just grab an extension cord and plug it in. (Bring some tape to secure it down better so robots can pass through if needed.)

Re: Power Management Recommendation for driver stations
 

Ed,
The venue should be able to dig a few power drops out of their house box in a minute or two. All it requires is a threeway extension cord at each player station.

Re: Power Management Recommendation for driver stations
 

We also have a small inverter with connectors to a 12 v battery. We are using some of the older ones that we don't want on a comp robot anymore.

We plugged in the laptop to this "charger" any time we were waiting in line.

Re: Power Management Recommendation for driver stations
 

Roger that, I copy your comments well !!

However I posed the question to someone in the know at the event and the answer was negative.

Who controls the field facilities ? The GDC ? FIRST engineering ?

The question needs to be asked because without consistent guidance from HQ there is going to be some confusion.

Our cart now has AC power on it so our alliance members can stay plugged in and charging during queueing. And we have a handheld AC kit for the opposing alliance so they can go ditto !!

When the teams move forward they can pull the plug and place their equipment onto the driver stations. All that doesn't interfere with any understanding that FIRST has at this moment.

Should I post this to GDC Q&A ?

Re: Power Management Recommendation for driver stations
 

We just made sure our classmate was always plugged in between matches, and plugged in over night. (Don't just power it off over night, the classmate phantom will suck down the battery anyway - no I'm not putting it in sleep mode.)

~David

Re: Power Management Recommendation for driver stations
 

It really shouldn't even take that long considering there already is AC power at the drivers station for the SCCF cases, as well as additional power drops for the fixed cameras on the corners of the field. I was surprised that FIRST didn't provide the ability to plug the Classmate into power on the field. It will be interesting to see how these PCs hold up in Atlanta, and if any delays are caused by teams are waiting for the laptops to wake up or if they fail from the long walks or waits in the queue.

While we didn't have any issues last weekend in San Diego with ours, there was a few rounds where our battery was dangerously low. Plugging it in when the bot was in the pit helped, but there really should be something on the field to plug them into. It's very likely that the veteran teams will need to reuse PC next year, and who knows what shape the batteries will be in by then. Maybe someone will donate batteries for the KoP :rolleyes:

Re: Power Management Recommendation for driver stations
 

Just out of curiosity how long were the inverters staying running on one of the robot batteries? I had thought of doing this at some point on Friday but wasn't sure how long of runtime you would get before you would need to recharge the batteries.

Re: Power Management Recommendation for driver stations
 

Ed,
It is my understanding that each event is slightly different. Most often the local regional committee is the one paying for the venue and services it provides. I have never had a problem asking for additional power in the Inspection area. I am concerned about power cords running between robot carts while in the queue for obvious reasons. If someone had thought of this before, there should be power at the driver's station for all robot control. The old IFI controllers were powered by the field when you plugged in.

Re: Power Management Recommendation for driver stations
 

Al,

If they are using the same field then I'd expect the power is still there ? I think it used to have about 4 outlet boxes built in for the IFI controllers.

I'll push the issue to the GDC so they can comment. Then students going to the next event can carry that doc with them and then they can meet with the event organizers on site. I'm concerned that the venue will resist this unless there is GDC guidance.

I'd imagine if the head inspector want more power well then "Captain we got to have more power !!" ( in my best Scottish accent ). I can see why you would not have a problem getting power.

We have run video equipment that uses more power than the classmate and we have run all day long, EASY !

We also use this setup to run public demonstrations outdoors and corporate / legistaive events indoors. All day long EASY !

Put the battery on the charger overnight. Check the battery midday while inverting just to make yourself comfortable.

Re: Power Management Recommendation for driver stations
 

My team actually uses this method to power our control system when we do parades. It allows us to drive the robot while moving!

The batteries last a whole day powering a control system, with heavy use. You should have no problem with one or two batteries charging your classmate throughout the day.

Although this year at Kettering we were shut down by a safety captain when we were using a robot battery to power something besides the robot... You should probably get a clarification from FIRST that this is a "safe" activity before using the battery solution.

Re: Power Management Recommendation for driver stations
 

I asked about player station power at KC.

The power that is normally run to the player control area is now ued to power the ball return timers (in the goals and in the return rack).

Re: Power Management Recommendation for driver stations
 

Ask the 'safety captain' to cite the hazard !

If you have a UL approved inverter using the same Anderson connectors in the KOP using properly insulated wire ?!?! then they need to cite the hazard. Ask for the lead safety person.

Re: Power Management Recommendation for driver stations
 

Using an inverter has its hazards, but it would be entirely
reasonable to have a dc to dc converter powered by a robot
battery, or any other battery, to keep the classmate topped
off between matches. It is a simple matter to match the voltage
and connector used to charge the classmate.

Eugene

Re: Power Management Recommendation for driver stations
 

Proprietary connectors and unique, non-standard, voltages make this hard. even once you get the voltage AND CURRENT to the proper value, the connector might need to be spliced in a manner that could be deemed unsafe, plus prone to failure. But, I am no expert on classmate power supply cables and connectors. If this wasn't first, I would suggest soldering a car dc connector (lighter) onto the battery to plug the inverter into, but, this is FIRST, so we can't do that. I hate proprietary connectors!

Re: Power Management Recommendation for driver stations
 

If you look at the connector, voltage and current limit, you
are likely to find an existing dc-dc converter for a laptop that
fits the bill without using an AC inverter.

Eugene

Re: Power Management Recommendation for driver stations
 

wrong wrong...

a) use a standard robot battery with standard Anderson connector

b) use a COTS DC-AC inverter. Sometimes the inverter comes with pigtails in the kit. One is simply plain wire. Fit inverter with a standard Anderson connector.

Then you can pull any battery out of your battery pool to run the inverter for demos, presentations, competition, etc.

The solution Eugene talked about is more elegant and suited to a dedicated application. This solution give you power on the go for classmates, hubs, routers, laptops, and is more general purpose.

I have this inverter - it has pigtails the are interchangeable. I got it at a truck stop

I have this one too - you put it in your cup holder in your truck or car.

It doesn't give you enough power to run a cotton candy or squishee machine.

Re: Power Management Recommendation for driver stations
 

Or make a simple Anderson SS50-to-cigarette lighter adapter so you can use the inverter without modification.

With the cigarette lighter adapter, you get even more options. We have a small handheld 12v vacuum cleaner that's been used on occasion with a robot battery. We also used an automotive FM transmitter to put the audio through the shop speaker system when we watched a DVD.

Re: Power Management Recommendation for driver stations
 

battery would not be as big of a problem of 832 and 2415 stopped being on the field at the same time. Together we caused the FMS to shut down about 3 times...and thats when peoples batteries suffered:D

Re: Power Management Recommendation for driver stations
 

We've used ours to power a car compressor to blow up balls over the years.

Re: Power Management Recommendation for driver stations
 

I can really see this becoming a problem in Atlanta. Teams leaving their pits after lunch to go to eliminations and not coming back for hours. And then for a select few moving on to Einstein. Yah, there are a few plugs available, but they will get a lot of use out there. Teams need to be wise about when to have it on and when to shut it off.

Re: Power Management Recommendation for driver stations
 

Well when they yelled at us they said something along the lines of "Batteries are only to power robots, etc, etc" They didn't talk to me, but that's what I got out of it from overhearing them.

And we wern't which may have been the problem (but that still didn't justify their reasoning)... We were using insulated clips on the battery. We may make an Anderson connector one for the future competitions!

Re: Power Management Recommendation for driver stations
 

I might have backed them up on that decision. The power contained in one of our batteries is capable of sever damage if misused.

Re: Power Management Recommendation for driver stations
 

I am an advocate for using an automotive DC/AC converter but do it safely.

Any good auto parts store will sell in-line maxi-fuse holders to put just after the battery. Good, solid, well insulated connections and some planning should placate the safety police.

JMHO,

Mike

Re: Power Management Recommendation for driver stations
 

Job #1 is Safety - get rid of alligator clips. I'd back up the safety guys if you didn't have Anderson connectors on the inverter.

Re: Power Management Recommendation for driver stations
 

REX has used the inverter solution for the past several years. Previously it let us do functionality checks in queu, but now we use it to top off the Classmate. We've used robot batteries with no problems, but occasionally we'll bring some much larger batteries that we bought for the purpose.

Re: Power Management Recommendation for driver stations
 

PowerStream has a line of dc-dc converters
for those who don't want to run inverters.

www.powerstream.com

Model ED1060-20V-5.5-2.1 appears
to be a match for the classmate.

Re: Power Management Recommendation for driver stations
 

This was a huge problem for us in SD in eliminations.
Our team borrowed a charged one from another team, but that in itself along with worrying about winning matches drove us nuts!!
I was going to post on Q&A.

I hope the GDC/FIRST instructs regionals to provide the power needed for classmate plugin or adaptor at the stations. It seems the easiest to address instead of asking all these teams to buy/make an adaptor for them.

Re: Power Management Recommendation for driver stations
 

For teams currently at this week's regionals, is there any power present at the drivers station? I'd kind of like to know if this is something they might implement, before I spend the time and money on my own solution.

Re: Power Management Recommendation for driver stations
 

No power at the WPI driver stations yesterday.

Re: Power Management Recommendation for driver stations
 

Just for some more ideas we use one of these (or its smaller cousin)

apc universal laptop battery

this one too


Just do an online search for "universal laptop battery" and you will find many devices. The advantage of these is they're typically small enough to either fit under the netbook or right next to it. All day Saturday and part of Friday we ran one of these, kept it plugged right on sitting right next to the classmate. Once we got back to the pit we plugged the classmate charger into the battery.

Re: Power Management Recommendation for driver stations
 

I ordered the unit noted below from PowerStream,
but they sent me model ED1075 (a more common unit)
instead. The hole for the center pin on this one
was 1.7mm and it is likely too small for the classmate.
If you order from these guys you need to call them and
make sure that they have what you need.

Eugene

Re: Power Management Recommendation for driver stations
 

Until we can convince the powers that be to provide Classmate power at the driver's station, teams who are not playing in the finals, may want to top off their Classmate batteries and offer them to teams who are playing in the finals. This is not the best solution but it will insure that finals teams can continue to control their robots.

Also, to any teams that are using the inverter/robot battery solution, I would like to recommend an inline fuse to protect the battery and inverter. These are available at automotive stores and a 20-40 amp breaker should do the trick. Please use the same wiring size vs fuse choice that is listed in the robot rules.

Re: Power Management Recommendation for driver stations
 

If you are using the PSoC board make sure to unplug it between matches, it's a real powerhog. At Chesapeake Regional, our Classmate was charged going into Elims. By SF 1-2 our Classmate battery was in the red and the PSoC was failing to connect (so we stopped using it). In SF 1-4 (a back to back match), the battery was very low and may have contributed to periodic network communication error. We would run for about 10sec then lose communication for about 2 sec (not sure the Classmate was the problem but since we didnt play a match afterward, it remains a possibility). Back in the pits the PSoc wouldn't work till I plugged the Classmate in. I couldn't reproduce the communication errors while tethered.

Re: Power Management Recommendation for driver stations
 

One of our team members has an uninterruptable power source: http://www.tigerdirect.ca/applicatio...2224&CatId=234

Would we be able to use this on the field to power the laptop?

Re: Power Management Recommendation for driver stations
 

Not sure if you'd want to carry the heavy thing around, especially on the field where it could be dropped accidentally.

-Tanner

Re: Power Management Recommendation for driver stations
 

As long as it is declared part of the operator console, fits on the shelf, and is safe, there are no rules prohibiting this.

Re: Power Management Recommendation for driver stations
 

Somebody correct me if I'm wrong, but I definitely didn't see any power strips in the queuing area at the Midwest regional as Bill's Blog indicated there would be.

I know the announcer asked at the start of elims for any non-elim teams with charged Classmate batteries that they were willing to share to bring them over.

Re: Power Management Recommendation for driver stations
 

Craig,
That is an overkill and is very heavy.

Re: Power Management Recommendation for driver stations
 

Agree with Al, it is an overkill to have on the drivers station. However, since you do have it, I would recommend you put it on your cart and have run off of battery power during matches if there are 1. no power at stations for a tournament or 2. no smaller universal battery purchased by your team.

Re: Power Management Recommendation for driver stations
 

scratch that, we'll probably get one of the things from the link in sanddrag's signature and use a power inverter...

Re: Power Management Recommendation for driver stations
 

really? That would explain why we could only get about a 5% charge between matches. Will try disconnecting it during philly

Re: Power Management Recommendation for driver stations
 

AndyMark is carrying an inverter with an Anderson connector.

We are using one that is similar, and we keep the classmate plugged in to it while we are waiting in the que.

I do know of one team that borrowed it to keep their laptop plugged in during a match, because their battery was almost gone. It was allowed at their player station.

I have not seen outlets at the player station or nearby at KC or BMR.

Re: Power Management Recommendation for driver stations
 

We used a dc-dc laptop charger with an anderson connector on it
at SVR. The one problem we did have was that our 110 volt classmate
charger died on Friday, we would have been up a creek without the dc-dc
charger. We used it to charge the laptop overnight on Friday night,
putting a fresh battery on it when we left the pits at 6pm. We then
used it all day on Saturday. It worked out well for us.

The 20 volt, 3.7 amp charger with the 5.5mm-2.5mm plug at
www.powerstream.com is ED1075-52. RadioShack
has a very cheap universal one with lots of plugs and adjustable
voltage, but you will have to check the plugs it has for a proper
fit.

Eugene

Re: Power Management Recommendation for driver stations
 

How do the classmate ac-dc converters work? are they just rectifier diodes? Is there anything preventing them from being used as dc to dc converters? {such as issues with the rectifiers releasing 'magic smoke'}

Re: Power Management Recommendation for driver stations
 

We will have take our dead classmate charger apart to see what is
in there. Even if it is a switched supply that can run on dc, hacking
together a high voltage dc power supply is a really bad idea that our
UL safety inspectors should frown on. Spend $20 at radio shack for
a suitable 12 volt charger!

Eugene

Re: Power Management Recommendation for driver stations
 

461 is the team that had to borrow the inverter from AndyMark. We had the second match of the day and arrived to a completely dead classmate in our pit. It worked great and we bought it on the spot. Thanks Andy!

Get one for yourself

Re: Power Management Recommendation for driver stations
 

Our guys went the inverter route, except they wired it up themselves and they stored the battery on the control board. It's crazy, but it works, we never had an issue with the Classmate, at least to my knowledge.

Re: Power Management Recommendation for driver stations
 

Eugene,
I am betting that the cable is broken as it leaves the wall wart. I will be very interested in knowing the outcome.

Re: Power Management Recommendation for driver stations
 

If you're coming to the NU CT regional, Rosie will be bringing our UPS's for use at the field drivers stations, if needed by teams. We did it at WPI and Kate (the FTA) thought is was a great idea!

Re: Power Management Recommendation for driver stations
 

Are teams disabling the WiFi capability of their Classmate during the event? Turning off my laptop's WiFi noticeably reduces power consumption.

Russ