[NSRCA-discussion] Servo wire and battery questions

[davel322 at comcast.net]

John,

2 lipo cells are used in series and are regulated down to anywhere between 5 and 6.5 volts.  With the electrics, servo draw is greatly reduced (figure 50 mah per flight), so you can use a much smaller pack.

Typical glow guys are usually running 1400-2500 mah and electric guys are running as low as 480.

The lipos are pretty reliable, as are the regulators.  Some (including me) are still using redundant systems of some kind.  On my electrics, I've been running dual voltage regulators (from Tech Aero, Ed Alt who is on this list) and dual 2s1p480 lipos for a 100% redundant system.  3 oz total weight.

Regards,

Dave Lockhart


-------------- Original message -------------- 
From: John Ford <astropattern at yahoo.com> 

Hi all,
Return-to-pattern after a long time questions...

Question #1
I used to use JR servo amplifiers on servos to eliminate noise and ensure strong signal over a long servo lead, especially to the back of the plane. Few of these, if any, are available commercially now, so I assume that there is little need for them any more? (Was never convinced they served a purpose to begin with, but I had never built a plane without them, and never had a problem)
I will be using JR 955 RX and digital servos. 
Maybe as simple an answer as "never an issue, regardless of servo wire length".
Maybe I should twist my wires?

Question #2
I used to use nothing other than large SR nicads for the flight pack, usually 1100mAh.
I notice that folks are now using Thunder Power Li-Po batteries, some as small as 480mAh, and several around 800mAh.  Doesn't seem to be much capacity to run six digitals.
I assume there is a Jaccio regulator to cut it down to 5V or so. Are Li-Pos reliable enough that only one cell is used, or are some folks using a SmartFly dual battery regulator that ignores one battery if it should fail?

I appreciate any calibration on what the "standard" setup might be. 

Thanks,

John





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From: John Ford <astropattern at yahoo.com>
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