[NSRCA-discussion] Voltage regulatormaintenance/replacement/reliability

Fri Jun 16 07:12:42 AKDT 2006

VRs don't "wear" out, but they can fail due to many causes. Replacing a good
one is not necessary. The only truly safe setup is using two batteries, one
regulated at a high voltage and one at a lower voltage. If the high voltage
circuit/battery fails then the low voltage one will get you back to the
ground safely. Since it is required for only a short time it can be a much
smaller battery.

One thing to remember: a system that draws 300 ma from a 5 V battery will
still draw 300 ma from a 8V battery with a 5V regulator. The regulator will
has to dissipate the difference 3V at 300ma as "wasted" power. Needless to say,
the mAh of the larger battery will have to be equal or greater than the
smaller one - you are still drawing the same current. Bigger battery = more
weight, unless you are changing technologies.

As far as replacing batteries: a lot of chargers will now tell you how much
charge you put back into a battery as well as go through a discharge cycle.
It's a good idea to do this on a relatively new battery, but not for the
first few charges. Log the data for future reference. When the battery will
only accept 85 - 90% of this value on a discharge/charge cycle, then I would
replace it.

-----Original Message-----
From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of White, Chris
Sent: Friday, June 16, 2006 8:26 AM
To: NSRCA Mailing List
Subject: [NSRCA-discussion] Voltage
regulatormaintenance/replacement/reliability

I know when a regulator fails when using a li-on battery the results are
catastrophic.   (lost one that way with a miracle switch)  How often should
a voltage regulator be replaced?  Is one VR better than another?  Are there
any checks which can be done to curtail disaster.

At this point I prefer flying 5C non-regulated nimh or nicads..just to take
the VR out of the loop.   I still have an airplane which has Li-on's and am
thinking hard about how far I should push the regulator.   Airplane is
probably 5-6 years old and equipment is probably original radio stuff.  I
have 153 flights on it myself and don't know how many the previous owners
put on it.  (The onboard Li-on is 2004 with the 153 flights..should it be
replaced?)

Your input is appreciated!
Chris

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From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of John Ferrell
Sent: Thursday, June 15, 2006 4:48 PM
To: NSRCA Mailing List
Subject: Re: [NSRCA-discussion] JR and un-regulated 6V

Three-terminal regulators dissipate the unused part of the power.
My Prophecy takes about 135 mils per flight to recharge. There are a lot of
factors that affect this number, especially airframe vibration.
I keep an eye on it and am more worried about it being consistent rather
than some value. 

John Ferrell    W8CCW
"My Competition is not my enemy"
http://DixieNC.US
----- Original Message ----- 
From: Wayne <mailto:wgalligan at goodsonacura.com>  Galligan 
To: NSRCA Mailing List <mailto:nsrca-discussion at lists.nsrca.org>  
Sent: Thursday, June 15, 2006 10:21 AM
Subject: Re: [NSRCA-discussion] JR and un-regulated 6V

Does running a regulator, like a 5.1v-5.5v or 6.0v regulator, have any
signifigant draw on the battery as it regulates the voltage?  I have been
using the MPI Miracle switch that regulates to 6v.  I can get (4) 15 min
flights on a 1650mil NiMh pack(Sanyo) before my ESC says to stop flying.
I will put back about 700-750 mil on the recharge.

Wayne Galligan 
----- Original Message ----- 
From: White, Chris <mailto:chris at ssd.fsi.com>  
To: NSRCA Mailing List <mailto:nsrca-discussion at lists.nsrca.org>  
Sent: Thursday, June 15, 2006 7:54 AM
Subject: Re: [NSRCA-discussion] JR and un-regulated 6V

Hi Matt,
Are you using low-impedence nimh packs?   Would you divulge your battery
source?

Thanks, Chris

  _____  

From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of
rcmaster199 at aol.com
Sent: Wednesday, June 14, 2006 5:03 PM
To: nsrca-discussion at lists.nsrca.org
Subject: Re: [NSRCA-discussion] JR and un-regulated 6V

I am doing that with NO problems. Fast charged on the way to field most of
the time, with a Serius fast charger. In my set-up, a 1650ma NiMH lasts
about 3 flights longer than a 4 cell pack of equivalent capacity. Equivalent
ending cell voltages of 1.20v unloaded (1.15V loaded with 1000 ma draw) for
either battery. 

Getting greater torque and speed as well as longer flight time. Best all
around

MattK

-----Original Message-----
From: Gene Maurice <gene.maurice at comcast.net>
To: 'NSRCA Mailing List' <nsrca-discussion at lists.nsrca.org>
Sent: Wed, 14 Jun 2006 15:36:18 -0500
Subject: [NSRCA-discussion] JR and un-regulated 6V
Anyone aware of any issues running unregulated 6v Nimh pack with JR Digital
servos??  

Gene Maurice
gene.maurice at comcast.net <mailto:gene.maurice%40comcast.net> 
Plano, TX
AMA 3408, NSRCA 877

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