stunthanger.com
Electric Stunt => Gettin all AMP'ed up! => Topic started by: Frank Imbriaco on May 14, 2012, 07:56:37 PM
-
Currently, there is some discussion , pro and con, on the RCU pattern forum about having a spark eliminator in line with the arming "switch". Castle Creations has stated that the spark is " your friend " and that seeing it tells the user that the capacitors are doing their job.
Personally, I just scuff the residue on my bullet connectors every so often , followed with a shot of electronic parts cleaner.
For product info. , check www.espritmodel.com/jeti-afc anti-spark-connectors-4mm-75a.aspx
(Credits to the RCU pilots who have posted)
-
That spark isn't your friend, but it is indicating that the capacitor is doing its job.
Dunno what to suggest if you want to use spark eliminator connectors but are worried that the caps may dry out: plug things together every so often without using the magic connector, maybe.
-
I read here somewhere that a spark eliminator may mess with the controller's automatic number-of-cells sensing (a dumb idea in my opinion: I'd hardwire it). If so, what size resistor could one use to do the desparking, yet ensure that the controller doesn't prematurely miscount the number of cells in the battery?
-
I read here somewhere that a spark eliminator may mess with the controller's automatic number-of-cells sensing (a dumb idea in my opinion: I'd hardwire it). If so, what size resistor could one use to do the desparking, yet ensure that the controller doesn't prematurely miscount the number of cells in the battery?
That depends on the controller software and hardware: without access to the controller design or a whole lot of experimentation, it is an unanswerable question.
-
Sorry. Castle ICE Lite 75 and 100.
-
Schulze F2B, too, as long as I'm asking.
-
10 ohm resistor will do its job well and quick, the problem is, that ESC can see full voltage and thus start its work while it is still connected with resistor ... for example beeping will make voltage drop and it can confuse ESC and it can think that the battery is discharged
proper and technically clean solution is ESC with slide switch which can cut internal 5V source ... it is also safe, because BLDC ESC simply cannot start motor if processor did not start its work yet
and I also do not think that spark means ESC is not confused and that capacitors does its job, because spark means that connector does not vave good contact yet, so voltage on capacitors can be still variable, so I do not understand that statement from CC very well
however solution with two connectors (one with resistor and the second direct) is certainly not very good, and may be that reason for that statement from CC, bceuase it takes long time untin ESC gets good connection to the battery, much better is one female connector with resistor connected paralel so that the male connector must touch firts resistor and then immediately directly to connector, I hope that software of CC is not so quick that it can react earlier than connectros are connected directly
I do not know arming procedure of CC, but I hope that they do not arm before ESC gets proper "iddle" signal for some time, so solution can be also slide switch on +5V wire to the timer, so that the timer cannot send iddle signal and ESC cannot arm while connecting battery, but only when the slide switch is ON , means when the battery is already well connected
-
Spark is the new bump, leave it alone!
-
Thousands perhaps millions of times a year a lypo battery gets hot plugged to a speed controller in the world. Unless you are dealing with a 50V to 100V battery system I can't see the problem. 3 to 4 cell lypo setup no problem for sure. 10 to 20 cell setup might have special considerations.
Just out of curiosity what is the concern? Damaged to the speed controller? Or perhaps damaged to the arming plug?
??? ??? ??? ???
-
I use 6 cells which will damage connector after 4 connections ... I do yearly 400 flight ... is 100 connectrors per yesr worth of using resistor for few cents? ;D
and battery is certainly also not happy to see such sparks
-
Where do the 10 ohm resistors go?
-
proper and technically clean solution is ESC with slide switch which can cut internal 5V source ... it is also safe, because BLDC ESC simply cannot start motor if processor did not start its work yet
Well, I'm not old enough to be close to attaining the rank of True Codger, but I still get cranky enough about other peoples embedded systems to have opinions.
The proper and technically clean solution is an ESC that waits for an appropriate interval before it measures the battery voltage, and doesn't rest on its laurels once it's done, so if after it's "decided" how many cells there are it sees a sustained higher voltage consistent with more cells -- it changes its mind.
That, and a technical circular on the proper way of doing spark arresting so as not to confuse whatever algorithm and hardware is being used.
Anything less is just leaving the customer (that's us) out to dry, and I don't find that an acceptable business practice.
-
I have been hoping that you would get sufficiently annoyed at existing controllers to start making them yourself. Sounds like progress.
-
Hi Gang,
The earlier (much earlier) CC High Voltage series ESCs (10S and 12S) had a slow start circuit built in!
It prevented the scary connector welding arc, and was the single greatest cause of hardware failure that caused repairs to be necessary.
I like the idea of a deadman switch that forces you to pass through a resistor connection very briefly. Igor has suggested what I think is the correct value resistor for this.
I'll go put my thinking cap on ...
Dean
-
Where do the 10 ohm resistors go?
I have it in female connector ...
-
Well, I'm not old enough to be close to attaining the rank of True Codger, but I still get cranky enough about other peoples embedded systems to have opinions.
The proper and technically clean solution is an ESC that waits for an appropriate interval before it measures the battery voltage, and doesn't rest on its laurels once it's done, so if after it's "decided" how many cells there are it sees a sustained higher voltage consistent with more cells -- it changes its mind.
That, and a technical circular on the proper way of doing spark arresting so as not to confuse whatever algorithm and hardware is being used.
Anything less is just leaving the customer (that's us) out to dry, and I don't find that an acceptable business practice.
Ok Tim, but what is "appropriate"? Trivial could be when the voltage is already stable, but it is stable also when connected via resistor, so it is not usefull solution. If it is on time basis, it can be different if you do not use resistor and different if you use solution recomended from one Czech producer of TMM ESCs:
http://mgm-compro.com/pdf/en-antispark-d230808.pdf
if you use such solution, it takes relatively long time to connect that second connector ... so how long? 5s? someone with simple connectro will feel that time too long ... so I still think that proper and especially safe solution is with switch
-
Perhaps a two arming plug set up. First plug has resistor. Second plug has dead short. Requires operator to plug up correct one first. Also requires removing both plugs to disarm. Plugs could be tethered together so that a tug on the tethered would remove both.