Model Forum / Radio Controlled / Air Models / November 2006

I've heard of jitters at fully charged 6V RX batts but it may have been the
RX giving the trouble.
They do sell regulators now days.  You can use a 2 cell li-po to run your
airborn pack
mk

This is the reason for the "BEC" battery eliminator circuit provided with
most 2 - 3 channel receivers as used in RC Cars, Boats, small EP Planes with
simple on/off motor functions.
Whilst many standard servos will operate upto 7.2V users operating 5 cell
NiCad packs must be very aware of over voltage killing servos either soon
after purchase during the "burn in" period of any electronic widget or over
an indefinite period. This especially so when 5 cell packs are fresh of the
charger and has a high float voltage.
A number of digital servos were burnt out at local track when racers started
to use 2 cell 7.4v LiPol packs - all now make sure a voltage regulators (5.5
or 6V output available) e.g.
http://www.acehobby.co.nz/ossb2/root/OSSBEC1/showitem.asp?PID=54613
increasingly seen in large RC racing boats and large scale aircraft are also
installed.
Note a minimum of 5A regulator is required for digital servo use and
preferred for most applications - those in older 2 ch RX are only 1.5A out
to servos. Drain by stalled or binding servos can be very high, especially
on higher voltages:
Batteries - graphic detail of stalled or binding servo ***
http://web.archive.org/web/20040421163540/http://www.rc1.com/radios/milliamps.html
Watch the specs on the BEC of all aircraft ESC and many are rated for max 2
servos or 3 micro servos. In need, lift tab on plug, remove red (+) wire
from RX lead and tape backward onto lead for future use in another model.
Much more info on my web page.
Regards
Alan T.
Alan's Hobby  Model & RC Web Links
http://homepages.ihug.co.nz/~atong