Fuses

hi all

in a feather weight, to be able to compete does it need a fuse? also i bought a power light from technobots but now need the lead, i cant see it on the site does anyone either have to sell or can see them on technobots?

cheers alex

It doesnt need a fuse, but to protect precious speed controllers if they dont current limit it is not a bad idea. Fuses are cheaper to replace than speed controllers.

do electrolize do this?

cheers alex

try maplin or halfords, or the scrap yard, there are plenty of fuseholders under the bonnet.

(Message edited by jamesb on February 11, 2007)

Dont electrolize have a built in fuse ? The ones I have do

I am thinking of fuesing the lead supplying the led,im worried that if either the led or lead get traped or damaged this will result in a short circuit across my 24v batt supply.Melting the thin led cable or takeing out my main fuse.both not nice things to happen.

I might aswell do it then it will only cost under a pound from technobots


thanks for the help
alex

I put two resistors in each wire going to the LED at the speed controller battery connector, that way a short with either or both wires would result in no damage execpt to the LED, depending on the fault.

I use an 80A fuse directly after the link. Doesnt cost much, and it saves my lipos just incase i draw too much current.

or just use the fuse as the link?

as i have many, many times (sorry pete :) )

at colchester we had a little trouble with block of wood

on the second day a fuse seemed to go, this has happened before and is the one on the speedo now both speedo fuses have gone once. what might be the cause? we cant go on changing the fuses ever event

alex

What rating are the fuses you are using?

Perhaps you could look at circuit breakers for protection which you then dont have to replace?

You could get temporary-set models which will self-reset after a certain time, thus if you experience a current spike during a battle for whatever reason the circuit breaker may cut out for protection for a few seconds and then resume conducting afterwards, cutting out again if the current resumes to be at sufficiently high levels.

Only really a suggestion for an alternative to fuses as opposed to a suggestion as to the cause of your high current/too low rated fuses woes. Without a good enough description or first-hand viewing its hard to diagnose problems like this.

The motor makes a good fuse !

Seriously though, in an ultra-competitive fight you want all your bot can give you. Consider if you need the fuse or not as the chances are all the expensive parts will have gone pop before the fuse has a chance to react anyway.

Just my 2 cents !

Ed
http://www.teamstorm.comhttp://www.teamstorm.com

well original they were the ones which come with the electronize 15A

i used to put 20A fuses in mine, the speedos took it fine and still run ok. I tend not to bother with fuses, mainly for reason Ed mentioned. They always seem to go when your really pushing your robots limits, and when your fighting at an event for a cash prize its worth taking them out and pushing your robot that little bit harder as a fuse always goes when the components have a little me left in them! Only fuse I run with is inline with the batteries at the batteries maximum discharge current but only as Im using LiPos. Although they are very usefull for testing.

first mod i make when using electronize 15A, is to swap the fuses for 25A or 30A versions.
They still pop before the controller does, but much less often than 15A fuses.

where in my circuit do i put my fuse, before the speed controller on the + wire on the batt?

Yes, Preferably as close to the battery as possible to minimise a short circuit with a damaged wire before the fuse.