[NSRCA-discussion] Voltage regulatormaintenance/replacement/reliability

Fri Jun 16 08:07:26 AKDT 2006

I have not used a VR yet, but I know from my electronics experience that the cooler you keep the components, the longer they last. If the VR is mounted to a heat sink, its reliability (MTBF, whatever) goes way up.

  Bob R.

Jay Marshall <lightfoot at sc.rr.com> wrote:

    v\:* {behavior:url(#default#VML);}  o\:* {behavior:url(#default#VML);}  w\:* {behavior:url(#default#VML);}  .shape {behavior:url(#default#VML);}                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 

    To: NSRCA Mailing List 

    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 

    To: NSRCA Mailing List 

    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
  Plano, TX
  AMA 3408, NSRCA 877

  _______________________________________________
  NSRCA-discussion mailing list
  NSRCA-discussion at lists.nsrca.org
  http://lists.nsrca.org/mailman/listinfo/nsrca-discussion

    <hr size=2 width="100%" align=center> 

  Check out AOL.com today. Breaking news, video search, pictures, email and IM. All on demand. Always Free.

---------------------------------

  _______________________________________________
NSRCA-discussion mailing list
NSRCA-discussion at lists.nsrca.org
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion

---------------------------------

  _______________________________________________
NSRCA-discussion mailing list
NSRCA-discussion at lists.nsrca.org
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion

_______________________________________________
NSRCA-discussion mailing list
NSRCA-discussion at lists.nsrca.org
http://lists.nsrca.org/mailman/listinfo/nsrca-discussion
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.nsrca.org/pipermail/nsrca-discussion/attachments/20060616/593aff3f/attachment-0001.html 