A fuse?
 

Fellas, I got this idea from a friend just now:

How about incorprate a kind of a fuse into a BL system?
A reading the BK guys took on my 99amp ESC showed that I run 130amps thru it for a peak or two :p

How about a fuse between the batts and the ESC?

It is ok to exceed the controller's rated amperage by up to 40% (info direct from BK's instruction manual). I wouldn't run a fuse. When you exceed the current draw for a split second, your car would shut down (very bad in a race!). Not to mention you would need to have a fuse or so on hand just in case.

I believe FastMhz uses a resettable fuse that resets about a second after it cuts out. This could be used between the controller and the battery without the BEC, and then a UBEC or RX battery could be used so that the radio would still work.

Yeah, I saw his fuse idea. I suppose it is a good idea in theory, but if you select the proper setup, it is unnecessary IMO. Of course, I mostly race, so any extra weight is automatically scrutinized and mostly ruled out for me!

Do not use fuses. They can harm your controller (blow it up) when the controller looses connection with the batteriepack. (the reason all the schulzes die is because of a loose connection) when you brake, the energy is stored back in to the batteries, (it uses the low internal resistance of the batteries to brake) once the connection with these batteries is lost, the energy can no longer be stored and it is very likely it kills the controller.

I don't know what a controller does when it looses power though, but if it looses RC it brakes as hard as it can.

I would never put my controller in that risc of a fuse. (how odd does that sound?)

Thanks guys.

Good point, Serum.

Agreed 100%. If you simply rolled your car for a 100ft with no battery plugged in(but the motor and controller attached), I think you would most certainly blow the controller. The brushless motor acts like a generator(generates power) and with no place to put the power, the controller must absorb it.

Okay, I perfectly understand.
But rolling a truck around for a few feet won't hurt, right? Because I did it lots of times on my workbench, for testing or removing tires and stuff.

Rolling around a little across the workbench isn't going to generate enough power to do anything. If you let your kid push it around the house like it was a tonka toy truck, you may be surprised to find a damaged controller, though!

Thanks, I'll keep this in mind.

Tonka... Back in the days.... When the yellow crane stole my heart.. The flywheel cars with the startbutton.. It felt like an RC when i poked that little red button of the screaming car with a stick...

You should not bring this up Mike.. A trip down to memory lane..

When i admitted my adiction, I decided to go public (lay hands on that flywheel car!!!) (about 2-3 months ago... Some things simple take time)

The man in the toystore stood there, looking at me, as he saw water burning.. What does a grown men got to do with a toy car I was selling about 100 years ago.... I started stumbling.. It.. Well... it is.. f..f..f for my n.nn..nephew..

'Nope... Sorry mister...' he replied... 'last car i sold as you discribed, was like 24 years ago..'

My therapist thinks i can overcome this obsession by building rc-cars..

I just got to get me that Tonka....

:L:

LMAO! Do I see a yellow body on one of your r/c cars in the future!?

I just had a though about using a fuse. Couldn't you add some large capacitors on the controller's battery input to store the energy? At least I would think that they would help a little bit. Not saying that using a fuse is the best solution though.

Probably with a small red button on it.. Don't get me started..

@metalman;

If the capacitors are so big that they can store the energy from braking, they can smoke the controller as well, so you need another fuse to prevent that.. (not saying that you need a fuse, you actually don't need a fuse at all)

So if you completed the truck it's more of a driving fuse than an RC car.. More of a Radio Controlled fuse actually..

I have a fuse on my system as mentioned above. It doesn't seem to popular on this forum though. In my background in electronics, you are taught to always fuse a circuit - so I guess I'm hard-headed in that sense.

Anyway, from what I've found around the 'net, I can't find any other referenses to fusing a brushless controller being bad, unless you are using a BEC as stated here:

RC Power FAQ

I'm still looking...after all, my polys did cost more than my controller, and the fuse will protect them in the event of catastrophic failure.

Perhaps, as mentioned in the link above, the issue being mentioned with breaking generating high voltages is due to people fusing between the controller and motor instead of battery and controller?

Serum - did you get this info "from the horses mouth" or other bad experience? I'll take the fuse out in a heartbeat if I can find some good evidence.

It is about electronics, and my schulze 18.97 died because of loose connections with the batteries.. It died after i braked.

If you want to keep you batteries intact and don't worry about the controller, use the fuse..

and it is logicall that the motor works as a generator, it simple uses the low, near zero Ohms of the batteries for braking. the fuse will end in an endless resistance, so the energy can no longer be stored.

Those spike killing diodes might work well though. you can put them over the 3 wires of the motor.. or on the 2 batterie wires. they simple short when they get above a certain voltage. and they can absorb 1500 watt spikes and you can use them paralell. I will get back on the name of those things

They are called transil diodes.

Just for you Serum, as I still remember my old metal Tonka crane.
I just loved that thing
http://img.photobucket.com/albums/v2...g/PHTO0006.jpg

[img]http://img.photobucket.com/albums/v247/cabking/PHTO0005.jpg
[/img]

bought this for my Lad. he loves it, when I let him have a go :D
Its not a patch on the big yellow crane, although the exhaust stacks are still made of that bendy rubber.:o

The mighty crane?!!! I had that too!!!

I also had a Mighty Front loader.. He didn't survived the concrete i transported with it.. (my dad was building a new house, and i just had to jump in for help, you know how it goes..) Being 4 years old, owning a front loader of that caliber, you just have to show off..


http://www.orpsalerooms.co.uk/images/8jan-2.jpg

It too had two rubber exhausts.. Mine is still going strong..