Printable View
Hi Craig....I have a friend who is very good with the old circuitboards...I have asked him to look into making a voltage cutoff switch for my robots and Yank. He said it would be possible and is looking into it tonight. I will get a few made up if there is the interest???
Hi Shane
I would be interested in one. For the new saint :mrgreen:
Perhaps if this is a point of interest for a lot of people it may be worth starting a new thread to discuss the parameters and functionality of such a device.
a device would be useful, as far as im aware sabertooths are the only escs with low vloltage cut outs, although a telematary system could also be used, http://www.hobbyking.com/hobbyking/stor ... metry.html
would give you a warning when your running out of power, and need to go easy? although i sopose that relies on the roboteers to stop, which could be hard in the heat of battle.
but such a device could be linked to an external bec control relay, so when switched ie, siren or light the output signal could engage/disengage a bec relay causing control to be lost and therefore all controllers and weapons etc would revert to failsfe positions,
just an idea i have considered
One thing I think is an issue as much as where people buy their lipo's is were people buy thier lipo sacks. A good lipo can cause the same damage if it catches fire as a cheap one. The major failsafe is that they are contained in a device which should prevent serious damage occurring to anything else.
There are a few 'fake' lipo sacks which you can buy and these simply do not do their job.
http://www.youtube.com/watch?v=ZEkewCjiDs0
Personally I always buy from a good UK supplier (al's hobbies, Hurricane models etc). Which gives some security. That said it is not unknown for reputable dealers to get duped by their suppliers (horse meat lasagne anyone?). Would it be sensible to introduce a 'metal box' for charging as this can't possible be faked?
Andy
Has anyone had any luck with a low voltage cut out for Lipo's ? If the ruling does get changed to mandatory then my robot would fail on this point.
Also, I've been reading the pages, and I totally agree with Ed regarding a lipo charging table and the fire extinguishers. My only problem with charging lipo's and having to stay with them, you miss all the action, especially if you're at the Robochallenge event (can't see the arena from the pits).
I did read that lipo's have to be secured down now. My Lipo's have padded protection around where they are situated so they don't rub on anything, but with the lid off I can move them freely (the bar that holds them down goes in with the lid). will that suit purpose or do I need another securing method ?
I don't want to be disqualified before I get to the UK champs.
OK, help my aching brain. At which voltage should the Lipos cut off at?
Is there potential in modifying one of these things? http://www.ebay.co.uk/itm/Low-Voltage-L ... 337f8a9f33
We have already purchased one to experiment.
Lipos don't like going under 3volts per cell.
If we are being realistic about a cut off then it will have to cut power to the receiver or robot as an alarm will be drowned out in the arena and a light would be easy to ignore or confuse with the power LED. That raises two issues, if it's a main power cut off it would have to be capable of flowing 200A through it. Unlikely to be reliable or cost effective.
That leaves you with cutting power to the receiver which again is not ideal as you still have a robot capable of movement by itself (although of course the tech check should omit this risk).
Other issue, how do you test the cut off during the tech check?