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HelicopterRadio - Spektrum DSM › Spektrum receiver keeps rebooting
12-20-2013 02:09 PM  3 years agoPost 21
jschenck

rrProfessor

La Vista, NE.

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Darren - Are you saying you only have the problem when running a NiMH battery and not when the LiFe pack is used? Simple solution - don't use NiMH.

Are the NiMH batteries AA size? If so that is likely your issue here. The AA size NiMH packs tend to be high internal resistance and are not good for high current draw like modern servos.

Also, if you run the connector outside the canopy then you don't need to pull the canopy off to plug in the radio battery pack. Take a look at the way I wired up my Trex-700n in the picture above.

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12-20-2013 02:13 PM  3 years agoPost 22
Pistol Pete

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Seffner, FL

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I spoke to some guys who all fly with switches they have never heard of the switch reducing the voltage
"resistance" is the key word

Higher resistance requires higher amperage to overcome it.

Voltage is inversely proportional to Current.

Current goes up, voltage goes down = brownout.

~~Enjoying the hobby one flight at a time~~

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12-20-2013 03:03 PM  3 years agoPost 23
cbflys

rrVeteran

Nesconset, NY - USA

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When ever you have a connection, be it a plug in connector or switch contacts - you have some resistance. Granted, with good quality connectors and switches - that resistance is probably negligable. However - poorly fitting connectors and switch contacts that are worn or pitted can present a fairly high resistance.

In this case, I think the voltage overhead available by using a 5S NiMH pack coupled with the high current demand of his digital servos probably rendered the connector/contact resistance as significant enough to drop the voltage below the minimum RX operating voltage - thus causing the brown-out.

All the evidence he presented certinally points to this conclusion.

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12-20-2013 03:19 PM  3 years agoPost 24
datidun

rrKey Veteran

N Ireland

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Hi Jschenck yes that is correct,it only happens when i use a 5s 6volt 2500 mah battery,BUT only when the voltage hits 6.6 volts,how i now this is because i have a meter plugged into the receiver,I fly pretty hard so im guessing around the second flight this is happening when up in the air,i obviously did not notice,as i still have full control of the heli as i usually have 3 to four flights no problem,I only noticed this on the bench,the fact still remains as to why the switch reduces the voltage so much with a nimh battery,I even took a pretty low voltage nimh battery reading 5.5 volts under heavy load plugged DIRECTLY into the receiver and it was fine,NO rebooting both lights stayed solid,so it looks like i cant use old school 6v nimh batteries any more with a 2.4 system,I will have to put in a life 6.6v,if did reboot in the sky how come I did not effect anything the DSMX reboots extremely quick.What size life batteries are you guys using
Darren

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12-20-2013 03:42 PM  3 years agoPost 25
Pistol Pete

rrProfessor

Seffner, FL

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http://www.hangtimes.com/a123_packs.html

2S-2500mAh

~~Enjoying the hobby one flight at a time~~

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12-20-2013 04:23 PM  3 years agoPost 26
BobOD

rrElite Veteran

New York- USA

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The JR "Heavy Duty" switch is rated at 5 amps. Your servos could be pulling twice that.
Also, have a look at a discharge ratings of the battery you're using.

Team POP Secret

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12-20-2013 04:29 PM  3 years agoPost 27
datidun

rrKey Veteran

N Ireland

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I just bought a life 6.6v 2100mah to replace the 6v 2500 mah nimh,im hoping it will work out well.

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12-20-2013 04:48 PM  3 years agoPost 28
jschenck

rrProfessor

La Vista, NE.

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The LiFe packs can maintain higher voltage even with a high load that strong servos and 'questionable' switches put on the pack. The NiMH may be dropping voltage quicker under load. That would explain why you don't see it with the LiFe pack even with the same switch. Run two switches and you have twice the current carrying capability plus redundancy if a switch fails.

Personally I would recommend staying away for NiMH for RX packs unless they are sub-C size cells. Those are big and heavy. A LiFe can be charged much faster, doesn't self discharge and can handle high current draw. You MUST count flights and recharge based on that - LiFe will give almost no warning going from 6.6V to flat in just a few seconds.

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12-20-2013 05:16 PM  3 years agoPost 29
datidun

rrKey Veteran

N Ireland

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Thanx are you still using the 2100 mah life pack.

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12-20-2013 06:07 PM  3 years agoPost 30
jschenck

rrProfessor

La Vista, NE.

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yes for 50 size machines. 90 size uses 3000mah LiFe pack. Use what will balance the machine.

Fly 3 flights and recharge. make sure to note how much it took to recharge. I personally get nervous when I've used 50% of the pack. So if I use 300mah per flight I would fly 3-4 flights on a 2100 then recharge.

I even use LiFe on my big electric heli's. I don't use regulators or BEC's.

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HelicopterRadio - Spektrum DSM › Spektrum receiver keeps rebooting
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