External power for LED worklights?

[geeknerd99]

This just sprang into my head a few minutes ago, and I don't really feel like digging through the rules right now.

I'm sure everyone at some point has had to bust out a flashlight at competition to light up some nook or crannie of their robot. This is not only easy, but very distracting, and usually not that effective.

Now, how much can a handful of white LEDs, a DC power plug, and some PWM gauge cable weigh?

String some around the inside of the robot in strategic places. The power would come from an external source. These work lights would not be connected to any robot circuitry at all, so they would not be able to light up during competition. Not being connected to robot circuitry also means less things to worry about electrical-wise.

I suppose it could be powered off the robot's battery through the use of a hard switch, but the external power falls more into our Nascar inspired pit concept for this year.

[GBIT]

that is a very cool idea and i would say follow the flow chart to see if it is legal.

[EHaskins]

I just took a quick look through the 2007 manual, and I didn't see anything that would prohibit it. Unless someone else finds a rule I missed I think I'll suggest that my team does that next year.

[GBIT]

i couldnt find anything either.

[Stuart]

I think it would be concidered decoration. and as long as you keep it all under weight I think its fine

[sanddrag]

there's no rule requiring that electrical wire and lights must actually be connected. you could throw a lot of things on the robot that don't have to be connected. a big vacuum tube for example. As an inspector for the past two years, I would say your idea is fine. But I would recommend having it fused.

[Al Skierkiewicz]

As to rules for this, the general heading is non-functional decoration. As an inspector, I am concerned for safety on and off the field so the inclusion of this type of lighting should follow all of the robot rules as to wire size, insulation, and circuit protection. Normally, this should be controlled by a Spike as well but since it is for use on the robot when the robot is off, that would be difficult. Any system would still be subject to inspection and the lead inspector at your event has the final say. In no event would you be allowed to parallel the connection to the battery and/or bypass the main breaker under the current robot rules, so you would have to come up with a different way to supply power. A second battery connector and fuse might work.

[geeknerd99]

Of course, the wiring would be in accordance with robot rules. Could the fuse be placed on the cart, thus simplifying the setup on the robot? Our cart this year is going to be a mobile pit station in itself, able to supply power for charging and tools.

We're also looking at finding a way to run the robot off the cart while it is in the pits so that we can cut down on the wear of our batteries (and because some years, changing batteries can be a pain). If we had another main breaker on our cart, identical to the one found on the robot, would that be legal?

Basically, if we wish to provide power from a source other than the robot while it is in the pits, if we duplicate all required elements (fuses, breakers, etc.), but leave them on the cart and simply have easy-access plugs running into the robot, would that be legal?

[SgtMillhouse648]

If you had a 12 volt power supply you could place one of the plug connectors to the battery on a break away in case autonomous code goes drastically wrong... id also make sure I put a switch on it just as a failsafe. I'd also suggest placing some blocks on the cart to elevate the drive off of the ground to work on it. Our cart has a scissor lift similar to royal assault's robot this year to keep the robot down low for travel, but can be elevated to work on at a safe level.
Malhon

[Al Skierkiewicz]

Originally Posted by geeknerd99

Of course, the wiring would be in accordance with robot rules. Could the fuse be placed on the cart, thus simplifying the setup on the robot? Our cart this year is going to be a mobile pit station in itself, able to supply power for charging and tools.

Daniel,
In real practice, there should be a fuse near the power source and on the cart. (Backup the backup) One protects the battery and the other the wiring on the cart.
As to adding power to the cart...Please be aware that there are electrical rules and codes that go beyond the robot rules that would come into play here especially for 110 volt AC wiring to lights, tools and chargers. I know that Underwriters Laboratories Inc. is taking a more active role in safety issues specifically homemade devices in the pits. I know of one team that was asked to remove a homemade power distro panel as it was deemed unsafe by an UL inspector at an event this year.

[Alan Anderson]

Originally Posted by geeknerd99

We're also looking at finding a way to run the robot off the cart while it is in the pits so that we can cut down on the wear of our batteries (and because some years, changing batteries can be a pain). If we had another main breaker on our cart, identical to the one found on the robot, would that be legal?

Basically, if we wish to provide power from a source other than the robot while it is in the pits, if we duplicate all required elements (fuses, breakers, etc.), but leave them on the cart and simply have easy-access plugs running into the robot, would that be legal?

The simplest solution would be to supply the cart-provided "ground power" using the regular battery connection on the robot. That would let you run any robot from the cart, without needing to do any specialized wiring. All you need is to have the battery connector accessible, which should already be the case.

[cooker52]

I'm just going to throw this in.

It sounds like a great idea, but why not just use a headlamp. It'll save weight on your robot and you also won't have to go through any inspections. Just my thought.

But on the other hand (as the argument goes on with my self), it would look really cool and catch a lot of attention having LED's, and you might be able to see in places that might be hard to see in with any other outside light source.

But, then again (has anyone else argued with themselves like this before?), head lamps CAN be cheaper in the long run, plus you won't have to worry about a chance of one of the LED's breaking in the middle of a competition (depending on where you place them obviously). And, on top of that, you could make a really cool pit crew uniform with some headlamps.

Most of my own argument within myself, the next part of it goes onto battery issues, which can go on for a bit, too.

[geeknerd99]

Last year, our frame design made for not-that-easy battery changing. It also made for 4 rounds where we almost ejected our battery out a side panel due to pop-rivets failing. Now, if there were some circuitry to charge the battery INSIDE the robot.... that would be awesome.

We understand the importance of wiring safety off the robot as well. I'm not quite clear on the details of the wiring, but our main electrician for this project really knows his stuff. He's had enough stuff blow up on him before that he's pretty much seen everything.

This cart is apparently going to be a senior design project for some of us, so it'll look good, and we'll have other people help us along the way. The point of this cart is to be safe (it'll have an extensive first aid kit and a fire extinguisher on it), and it would be pretty ironic if the cart itself was a fire hazard.

Actually, this whole thing ties into our uber-cart pipedreams that we've been having since my freshman year. Our freshman year, our cart was basically a crappily welded projector-cart looking thing. Over the years, cart designs have really evolved. This year we're going all out.

We're even putting hand brakes on it in anticipation of the elevation changes in Atanta. Plus, it'll break down into small enough modules to easily put into a van or something.

Do expect photos over the next few weeks as we start getting our materials together. I'm just kinda heading this project, managing resources mainly, so I don't have my hands on anything that I could post on CD. Our guy who's doing most of the design and material procurement needs to post more on Chief Delphi. *nudge nudge, Peter*

[cooker52]

Originally Posted by geeknerd99

This cart is apparently going to be a senior design project for some of us, so it'll look good, and we'll have other people help us along the way. The point of this cart is to be safe (it'll have an extensive first aid kit and a fire extinguisher on it), and it would be pretty ironic if the cart itself was a fire hazard.

That would be almost to ironic. Sounds great. I wish ours would be a little more collapsable. Ours is nice and big (and heavy. Takes up a lot of space, but can haul a lot. It does take some maintance though). But, it has it's own power supply and we used to have a compressor and air tank on it. The battery was rechargable and we would basically just plug the entire cart into an outlet and it would charge. We always had our robot plugged into the cart before the match, so that we could make sure that all of the air tanks were full and everything was alright. It was very handy.

Sounds like your cart is going to be really nice, what type of material are you using? I look forward to the pictures. And get "Peter" to post some more, I'm getting very interested.

[Al Skierkiewicz]

Originally Posted by geeknerd99

We understand the importance of wiring safety off the robot as well. I'm not quite clear on the details of the wiring, but our main electrician for this project really knows his stuff. He's had enough stuff blow up on him before that he's pretty much seen everything.

As always, you can contact me via PM with questions or ideas, anytime. When we are closer to competition, there is always answers through FIRST as well via Q&A.