[NSRCA-discussion] Voltageregulatormaintenance/replacement/reliability

Fri Jun 16 08:52:22 AKDT 2006

Jay,

Thanks very much for your reply.  It was most helpful.  Unfortunately on
the battery deal I only have a Power flite charger and it has no
discharge or charge measurement capability.  I'll probably just pull the
VR & Lion and fly it with a 5C Nimh.  Very good info ...thank you!

Chris

________________________________

From: nsrca-discussion-bounces at lists.nsrca.org
[mailto:nsrca-discussion-bounces at lists.nsrca.org] On Behalf Of Jay
Marshall
Sent: Friday, June 16, 2006 10:12 AM
To: 'NSRCA Mailing List'
Subject: Re: [NSRCA-discussion]
Voltageregulatormaintenance/replacement/reliability

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

________________________________

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 Galligan <mailto:wgalligan at goodsonacura.com>  

	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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