Sparking Connection

[pbrguy]

I just converted a Sr. Telemaster to electric and it seems to bench test fine - Monster 60 motor, 80A ESC, and 6 cell 22.5V Lipo. Whenever I mate the battery to the ESC (Dean's Connector), I get a fairly big spark. I've checked the wiring, and after mating the connector, it fires up fine. Any thoughts?

[pda4you]

Awe..... The spark o life...

It is a normal thing - nothing wrong.

Mike

[LBJ]

On Castle Creation's SC packs they say "the spark is your firend!"

[wellington53]

Some stuff to read here,
http://www.rcgroups.com/forums/showthread.php?t=937877&highlight=big+spark

[tIANcI]

You can cut down on the spark by using a capacitor but for me, I agree with the rest. Basically, no spark means big trouble! Wait till you use a bullet connector, you will see a much bigger spark on 10S ... 6S sparks are small. Hehehehee ...

[ditchit]

Once got a spark when my gold wedding ring touched across two terminals on a deans ultra plug on a 6 cell pack. Very painful small burn. Don't ask me how, cause it shouldn't be possible. That weren't no good spark. :o

...but yeah, at 10S-12S, it turns into a spark and a crack. Makes all the other 3S fliers at my club curse occassionally...

[Lynxman]

You can cut down on the spark by using a capacitor but for me, I agree with the rest. Basically, no spark means big trouble! Wait till you use a bullet connector, you will see a much bigger spark on 10S ... 6S sparks are small. Hehehehee ...

You mean a resistor? Adding a capacitor will just increase the strength of the spark.

[tIANcI]

I believe its a capacitor across the plugs on the ESC side of the DEANs. I may be wrong ... but I think its that. I have yet to try it. Seen it on my QUARK and read about it somewhere in RCG. A resistor will cause resistance and ... heheheheheee ...

ditchit ... how are you?! Good to see you again. Hey you should see the spark on a 10S with bullet connectors. I got a 10S set up for my pal, he bought the ETurbax ... man after connecting it for the first time be rang me up immeidately, he was surprised about the spark. I thought he was being a woos till I saw the size of the spark! Its a nice blue one ...

[Lynxman]

The reason you get the spark is because of the high current charge of the capacitors when you connect the battery to the empty capacitors. The capacitors already on the ESC are connected in parallel to the battery wires.

The resistor trick is to put a resistor in parallel with one of the connectors and contact the battery connector with it before you plug in the connector. This charges the capacitors slowly.

[ditchit]

ditchit ... how are you?! Couldn't be better mate. Moved from the Funjet to the Ultrafly Spear. Same game...trying to go faster and lower...trust you're well.

[wellington53]

The reason you get the spark is because of the high current charge of the capacitors when you connect the battery to the empty capacitors. The capacitors already on the ESC are connected in parallel to the battery wires.

The resistor trick is to put a resistor in parallel with one of the connectors and contact the battery connector with it before you plug in the connector. This charges the capacitors slowly.
Exactly!

[Lynxman]

Some ESCs have an anti-spark circuit. My Kontronik Power Jazz (a monster of an ESC) has this feature and it works perfectly. I'm sure it's possible to make an aftermarket circuit to connect on the battery wires to eliminate the spark.

[tIANcI]

Okay its a resistor to make the capacitors charge slowly. Gotcha!

Ditchit ... I am great and all is good. :) No more FJ for me for the moment. Am trying to get more into F3A for a bit to learn how to fly straight!

[F1 Rocket]

https://www.espritmodel.com/index.asp?PageAction=VIEWPROD&ProdID=9498

Danny :)

[jrb]

https://www.espritmodel.com/index.asp?PageAction=VIEWPROD&ProdID=9498

Danny :)



Interesting; looks like it does more like this -- Long wires to the ESC need capacitors: http://www.rcgroups.com/forums/showthread.php?t=990130


Rather than the picture below ( http://homepage.mac.com/kmyersefo/ampfeb09/ampfeb09.htm ):

[tIANcI]

https://www.espritmodel.com/index.asp?PageAction=VIEWPROD&ProdID=9498

Danny :)

Yeah this is what I am talking about ... its capacitors that are used to suppress the spark. Hmmmm ... guess both ways work.

[Lynxman]

Adding capacitors increases the spark. The resistance in the circuit will be lower so the current as the connection is made will be higher and produce a big spark.

When you connect a high voltage source to a discharged capacitor you get a spark. When you connect a high voltage source to four capacitors in parallel you get a bigger spark as the charge current is four times as high.

[jrb]

From a another current thread ( http://www.rcgroups.com/forums/showthread.php?t=990130&page=2#post11443153 ):



The larger the caps, the bigger/longer the spark. More anti-spark tricks:
http://www.rcgroups.com/forums/showthread.php?t=939421&highlight=mgm+compro

Vriendelijke groeten ;) Ron

[tIANcI]

Lynxman ... so the Esprit suppressor should not work since they are capacitors and that using it may just cause a bigger spark? Hmmmm ... this is confusing now.

[jrb]

Sure looks to me just to be caps across the leads – which would increase spark!

https://www.espritmodel.com/index.asp?PageAction=VIEWPROD&ProdID=9498

Spark Suppressor 63V w/Deans

Placed between the main pack and ESC the Anti-Spark module contains three capacitors that absorb the initial burst of energy from the pack that normally causes a large spark/arc across the connectors.

Works up to 63V (16S)

[Carl Petersen]

I have one of those in my car. They said it would double my miles per gallon. :)

That's just silly. Lessening spark is about limiting the inrush current while the connection is made. Adding caps just makes it worse since caps present a short to changing voltage (AC). In order for this to have any effect there must be some voltage/current limiter in play.

[Lynxman]

I talked to an electronics friend and I think I can make an automatic spark suppression circuit, but it would require that the original capacitors on the ESC are removed and replaced by the circuit.

The idea is to use a circuit to replace the original ESC capacitors. The circuit consists of a resistor in series with a capacitor, and a transistor that shorts the resistor when it is triggered. A voltage regulator (a BEC with the capacitor removed for example) needs to be connected in parallel with the circuit to trigger the transistor. This method will let you connect the battery with a low current through the capacitor. Immediately after the connection has been established the transistor will be triggered and short the resistor. As there is now a good contact in the battery connector it does not matter if the capacitor charge current is high as it won't spark (sparks happen when the current crosses an airgap). The transistor will have to be designed to handle the ripple voltages and currents that the capacitor may demand during use.

A simpler solution would be to cut one leg of the ESC capacitor and solder a resistor in series with the capacitor and a switch in parallel with the resistor. Connect the battery with the switch open and then close the switch before flying. This is prone to neglect though.

Another solution, which I've used before is to solder a resistor in series with one battery wire, and have a jumper in parallel with the resistor which can be shorted with a Deans for example after a few seconds.

[F1 Rocket]

It looks like we misinterpreted the intended use of this product. Sorry for the confusion :o I have corrected the info on our website.

https://www.espritmodel.com/index.asp?PageAction=VIEWPROD&ProdID=9498

Danny

[tIANcI]

Can we not live with the spark and ensure that we are not near any gasoline? :)

[Lynxman]

Sure. It's not a problem other than some wear on the connectors. Some people make a sacrificial connector which they connect first to absorb the impact of the spark.

It's kind of cool to scare the glow flyers with a big lightning in the plane too. :D

[Carl Petersen]

It looks like we misinterpreted the intended use of this product. Sorry for the confusion :o I have corrected the info on our website.

DannyThanks Danny, sorry if I was a hard on you but it did sound a little bit like someone selling snake oil.

Can we not live with the spark and ensure that we are not near any gasoline?Yes you can but it will ruin your connectors eventually. The popular Deans are rather susceptible to this wear and tear. I won't go into why some of us refuse to use Deans connectors. That's another subject.

Spark suppression, or contact suppression, is used a lot to prevent arching, and accompanying deterioration, of relay contacts. What we need are ESCs that have two connectors. One to handle the high current loads and a smaller one with a current limiting resistor. Connect the smaller one first, wait a second or two so the voltage equalizes and then connect the larger connector. Perhaps if we petition the ESC manufacturers we can get them to include the second connector at least in the higher voltage ESCs where it's definitely needed.

[ditchit]

Hacker MasterSpin 170, which I'm lucky enough to own, has this exact feature Carl, as does the 200. Great bits of kit. And I use Deans in the setup. No sparking so no deterioration in the plugs. Works for me.

[Carl Petersen]

Hacker MasterSpin 170, which I'm lucky enough to own, has this exact feature Carl, as does the 200. Great bits of kit. And I use Deans in the setup. No sparking so no deterioration in the plugs. Works for me.That's good to hear. I pretty much use the HV CC ESCs which don't have such nice features. Maybe I should spend a little more and see how the other half lives. :)

[ditchit]

I'm not the 'other half' believe me. I had to scrimp and scrape for that beauty. ;>) I suspect quite a few of us do that to get the gear we want.

[tIANcI]

Yeah ... the arching will cause some wear and tear for sure. I can see it on my DEANS. I am so tempted to go big but the price of the ESCs are what keeps me away from it all.

As I asked in another thread, I saw going with an AXI 5330D as the 'cheapest' way to fly a 100cc EP.

Ditchit ... what you got that MS 170 in? A giant EDF? :)

[wellington53]

Can we not live with the spark and ensure that we are not near any gasoline? :)
You can live with if it's on the small side but when the spark is at the point of arcing then it's a problem. I had this happen to me once and it instantly melted the connectors on the Deans and scared the crap out of me, that's when I made a suppressor mod! I'm not sure if you read what I did to eliminate the spark but here it is again incase,
http://www.rcgroups.com/forums/showthread.php?t=935350

[ditchit]

Ditchit ... what you got that MS 170 in? A giant EDF? :)

http://claregrace.brinkster.net/rc/mountedHackerA80-10.JPG

Just waiting for the drilled spacers to slide over the M6 bolts then I'll be ready to go...but maybe a giant EDF one day ;)

[tIANcI]

Wellington ... lemme try out the mod and see how it goes. Not been flying my 10S set up of late but it would be really good to try out the mod.

Ditchit ... nice nice ... 12S set up huh? I am stuck with my fives ...

[ditchit]

Well...double them to 10S then...what the hell you waitin' for...

[tIANcI]

I already have a 10S MidWest CAP232 ... din't you know that? Have a look ... I think I need to try this spark suppression thingy on her.

[ditchit]

Nice CAP Tianci...got any video of it in the air?

[gp125racer]

The spark is a normal occurance.

Should you be concerned about the 'wear' placed on your connectors, you might want to consider building one of these for yourself. I run 3s - 8s, and have yet to build one.

http://static.rcgroups.com/forums/attachments/2/3/7/5/a1726156-108-Resistors.jpg

Hope that helps!
Don

[tIANcI]

Don ... I guess with the DEANs its the same too. Add another connector on the positive side, attach that before the connectors are plugged in. :) I will go make one next weekend.

How would I know how many ohms are required for 5S, 6S or 10S. Is there a guide please? No more wear on my connectors from now on!

Ditchit ... I did not make any videos and I just sold her last week. No more last flights! Need to strip her. My pal wants to go with a gasser. I used the DualSky 6360-210 KV with an APC 22x10 ... power is good for scale aerobatics. It was my first 10S project and that was to test it out with cheap stuff. I am happy with how she flies.

[eye4wings]

Just want to thank you all for this thread.
Very informative - I'm just getting into 5s and noticing the spark! This should save some gold getting vaporised!

[eye4wings]

Yep, that works great!
The system works with a 22ohm resistor - it was the nearest I had to 10 ohm - I guess it's just a matter of the charge-up taking a millisecond or two longer, but by the time I've fumbled around with the main connectors (4mm Gold) several seconds have passed anyway. I used 2mm gold connectors for the strap so as to avoid any confusion.
Thanks again!

[Geoff Dryer]

This thread is very informative. Thanks.

How many ohms should I use for a 12S configuration?

[Carl Petersen]

Doesn't have to be exact. ~50 Ω would do.

[Geoff Dryer]

Thanks I may give it a test. The spark generated by my Castle 110 HV is rather frightening and it wears out my Deans plug shunt rather quickly.

[wellington53]

Thanks I may give it a test. The spark generated by my Castle 110 HV is rather frightening and it wears out my Deans plug shunt rather quickly.
If your like me Geoff, you will be so relieved after you do the spark mod. I can live with the spark from a 6s setup but when you get to 10-12s and beyond volts, it's not funny anymore! Right?
Glenn.

[Geoff Dryer]

I certainly make sure that my fingers are dry!

[drstillpatient]

This thread is very informative. Thanks.

How many ohms should I use for a 12S configuration?

I used the 50 Ohm resistor for my 12S setup but would still get a tiny spark, and then the resistor just didnt work anymore. I replaced it with a 100 ohm resistor and its been working perfectly for a couple of months now.

[Carl Petersen]

I used the 50 Ohm resistor for my 12S setup but would still get a tiny spark, and then the resistor just didnt work anymore. I replaced it with a 100 ohm resistor and its been working perfectly for a couple of months now.Not only does your resistor need a certain ohmic value you also need to consider the peak current or wattage. You used too low a wattage 50Ω and it burned out. The 100Ω sees half the current (half the peak watts) so it will last longer but it takes twice as long to charge up your ESCs capacitors. Neither value is wrong, but if your going to use a 50Ω resistor make sure it can handle the in rush current (wattage).

[jijohans]

How many Watt's on a 12S setup and 47ohm?

[eye4wings]

Sorry if we've left you hanging jijohans, but guess you've sorted it by now anyway.
It's going to depend a bit on what ESC you're using, but I would guess you won't be far out using .5W at 47 ohm. That's what I used on 5s and half the resistance with no problems. Obviously more wattage is better in this application, so if you only have a larger resistor in your spares box - no problem. It's only when trying to skimp it we get trouble. (and what does a resistor cost anyway!)

[Tram]

Don ... I guess with the DEANs its the same too. Add another connector on the positive side, attach that before the connectors are plugged in. :) I will go make one next weekend.

Seems pretty simple... Add a small connector with a 50 ohm resistor to the + side of the battery and the + side of the ESC..

I am running 2 - 6S packs in my 12S setup.. I would think I'd only need to run this on one of the packs, right? The idea should still be the same..

Jeff
www.CommonSenseRC.com

[eye4wings]

Yes, confirmed.
You only need it for the final connection to the ESC.

[2lo]

I just tried this with a 10s setup. 37 ohm resistor .5watt 5% tolerance from radio shack. 99cents. :D works like a charm :D

[eye4wings]

Ah! Just noticed a trifle belatedly...
Deans connectors bring up a potentially different scenario.

tIANcI may have found out by now that the spark may still be there - although possibly variably reduced.

The reason for this is that it would be no use connecting the positive side's shunt resistor if the main negative connector is not in place to make a circuit allowing current to flow charging the ESCs capacitors.
Plugging in both pins at (give-or-take a microsecond) the same time will not give the benefit unless the negative side is connected first and a pause left before completing the insertion of the positive.
I would suggest for anyone using connectors which make contact for positive and negative wires at the same time, that a two pin plug connection should be used for the shunt. The negative wire does not need to be any thicker than the positive shunt wire as current is low on both sides of the circuit (the current being determined by the value of the resistor) and it may be that a pair of those awful Tamiya connectors we all used to cut off and replace with something that wouldn't melt into a blob of hot plastic might do the trick admirably.

[2lo]

Running two 5s in parallel, using a Y harness with deans. Plug in the battery with negative side going to the ESC first, plug in shunt, wait a couple of seconds, then plug in second pack. I've had no sparking like this :D

[wellington53]

OK, What's a shunt?

[2lo]

Sorry should have said resistor, but this is what I used.

http://www.radioshack.com/product/index.jsp?productId=2062313

[eye4wings]

Yes, sorry, I started the use of the word 'shunt' in this thread.
I suppose I had in mind the railroad analogy where a goods train might be routed off the main line to allow the express to go through.
A shunt is a second line that bridges between two points of a track - in the same way a 'jumper' is used on a PC board or some such. In our case it is the 'slow train' charging up the ESC capacitors so that the 'express' can then be direct routed.
There, now that's as clear as... mud?

[2lo]

I like that analagy:)

[wellington53]

Yes, sorry, I started the use of the word 'shunt' in this thread.

There, now that's as clear as... mud?
Absolutely, I was wondering if there was something else out there that suppressed the spark, I use the same resistor on anything over 6s,
wellington

[eye4wings]

Yes, same resistor by all means! Having used the last 27ohm and 33ohm job from my spares box I bought a small supply.

The ESC takes its initial charge in microseconds so by the time we've fumbled for the main positive connectors and got them engaged it's probably wondering if we're EVER going to get started!

Biggest cell count I've ever used is 5s and I was worried by the spark, so what the spark would be like for twice that number I dread to think!

Thinking further about using a Tamiya connector so as to connect both lines at the same time I think I might just give that a try some time as I do sometimes find myself getting memory fade and forgetting to do things in the right order.
Another possibility that might be a bit smarter would be to use the same plug that the cells use for balancing (JST?) and connect the resistor to the ESC side. That would entail an absolute minimum of extra weight and form a forceful reminder as to what cell count was supposed to be connected to that particular plane as it would be mismatched with any other than the right one. Foolproof always seems a good idea to me!

[wellington53]

Biggest cell count I've ever used is 5s and I was worried by the spark, so what the spark would be like for twice that number I dread to think!


I'm regularly using 12-14s setups with Deans plugs, What happened to me last back-end and this was before I was got to using a resistor, the Deans plugs arked just as you were expecting a spark, melted both plugs and in an instant hot metal shot all over the place and needless to say it scared the crap out of me!
wellington

[eye4wings]

And both you and the ESC survived?!
That sounds like a real 'my life flashed before my eyes' moment!
Good to be alive eh?

[jab]

Spark.. hehe.. Last year I made a high current on/off switch using a deans connector for a electric converted .60 size cap using 6S. Long story short I was in a hurry when soldering the plugs and later on when I tried turning "on" the switch, it did not go as expected.. :rolleyes: My fingers where black with soot from flash melted cover, balsa and deans plastic.

[wellington53]

Spark.. hehe.. Last year I made a high current on/off switch using a deans connector for a electric converted .60 size cap using 6S. Long story short I was in a hurry when soldering the plugs and later on when I tried turning "on" the switch, it did not go as expected.. :rolleyes: My fingers where black with soot from flash melted cover, balsa and deans plastic.
And some say the spark is your friend!

[drstillpatient]

And some say the spark is your friend!

lol .. not when you get the wiring polarity wrong... that spark then is a whole different experience :p

[Tram]

Ok, so what is the correct way to wire up this setup on a set of Deans?

Can I still just throw a resistor on the + side of the Deans that will be connecting to the ESC?

I've got my ESC wired with 2 plugs to skip the series connector at the battery level and will be soldering up some packs today and would like to try this..


Jeff
www.CommonSenseRC.com

[wellington53]

Jeff, Here is a thread I did on the eliminating the spark although it never got much attention but for me it works flawlessly-
http://www.rcgroups.com/forums/showthread.php?t=935350




Let me know if you want to know more.
Glenn.

[wellington53]

Double post

[Tram]

Awesome.. :)

I'll give it a shot.. Thanks

J

[steve1814]

So, to ask this question: if I wanted to hook up the resistor across my arming plug and leave it as a permanent fixture, would it work? I am wondering that when the arming plug is inserted, the current will flow through the path of least resistance (hopefully the arming plug) and not burn up the resistor.


See terrible diagram attached....
Cheers,
Steve

[Lynxman]

Did you forget to draw the battery connector? That system will eliminate the spark. I used a system exactly like that on a 60 size Edge 540 once. The resistor might possibly burn if you leave the battery connected for several minutes without the arming plug though.

[jijohans]

Search no more, here is your answer for all your troubles..
http://shop.rc-electronic.com/e-vendo.php?shop=k_emcotec_e&SessionId=&a=catalog&t=11&c=764&p=764

[steve1814]

Search no more, here is your answer for all your troubles..
http://shop.rc-electronic.com/e-vendo.php?shop=k_emcotec_e&SessionId=&a=catalog&t=11&c=764&p=764

Thanks, but for that kind of money I'll stick to my $1.95 resistors and doing it manually. Nice system though, I like the "gas cap" look and the pull before flight flag. Too bad it is $90.00 plus shipping.:(

Cheers,
steve

[TCM]

Could the experts out there tell me if the attached set up looks feasable. The setup is for a 1/4 cub so I am not looking to pull huge amps. Basically I am trying to cut down on the number of connections pre flight. The new hobbywing pentium HV esc comes with a resistor preinstalled on the neg side of the esc. I am trying to get away from having to have another small lead from the batt pack which needs plugging in first to the spark lead on the esc before plugging in the shunt. In the diagram if I plug the 3 connections ie +ve to +ve (batt, esc), +ve to -ve (series batt) then batt -ve to shunt. When I need to go live push the rocker switch to arm ESC capacitors then plug in shunt. The rocker switch can then be released to take it out of the circuit. This would also mean once I have landed I can remove the shunt and the circuit is no longer live. Your comments would be much appreciated.
Cheers
Tim

[leccyflyer]

The spark is a normal occurance.

Should you be concerned about the 'wear' placed on your connectors, you might want to consider building one of these for yourself. I run 3s - 8s, and have yet to build one.

http://static.rcgroups.com/forums/attachments/2/3/7/5/a1726156-108-Resistors.jpg

Hope that helps!
Don

Thanks for this - I'll be incorporating it into my 6s set-ups from now on. That sparking isn't funny inside a tight fuselage.:cool:

[sneasle]

Could the experts out there tell me if the attached set up looks feasable. The setup is for a 1/4 cub so I am not looking to pull huge amps. Basically I am trying to cut down on the number of connections pre flight. The new hobbywing pentium HV esc comes with a resistor preinstalled on the neg side of the esc. I am trying to get away from having to have another small lead from the batt pack which needs plugging in first to the spark lead on the esc before plugging in the shunt. In the diagram if I plug the 3 connections ie +ve to +ve (batt, esc), +ve to -ve (series batt) then batt -ve to shunt. When I need to go live push the rocker switch to arm ESC capacitors then plug in shunt. The rocker switch can then be released to take it out of the circuit. This would also mean once I have landed I can remove the shunt and the circuit is no longer live. Your comments would be much appreciated.
Cheers
Tim


Should work fine, yes.