Eliminating the RX Battery

[P. Tritle]

A friend of mine came up with a cure for the onboard Rx battery. The old Hitek 6-10 ESC is a great little unit, but is not BEC equiped. To solve the problem of charging NiCD's or replacing Alcaline batteries, we're now using a voltage regulator off the main power battery.
The unit is Radio Shack part # 276-1770, and cost about about $1.50. It will handle input up to 35 volts with a 5 volt output--mine measure 4.99V--and can handle loads up to 1 amp. Wiring is simple with 1 common ground lug and 1 lug each for voltage in and voltage out.
The B+ and B- leads are soldered to the main battery plug, the regulator wired into a servo lead, then plugged into the battery cavity of the Rx.
PAT

[Tachikaze]

I use the same technique, but experience will tell you that you should add a heat sink to this and I run three of these in parellel to assure no failure.
I arrived at the pond on one occassion where the 1/72ns scale DKM Bismark was dead in the water. The single voltage regulator in the unit measured as it was working, but when you turned it off and turned it back on there was a power surge. Servos do not like high voltage, it fried all three servos on board.
I would use the same techinque you have here, but place a heat sink on the unit( may be over kill, but you never know) and then run another two units in parellel, all attached to the same heat sink.

[P. Tritle]

Tach, Thanks for the input. I ran the St.Elme last week for almost 2 hours, the regulator wasn't cold, but it wasn't by any means "hot". My biggest concern was overloading the 1A max load, but figured with only one servo it wouldn't be a problem.
PAT

[Tachikaze]

I have seen that it is not so much as an over draw by the servos(especially if you are only using one) but a power surge through the regulator. It is momentary and you only note with a meter on the unit when you power it up. This will fry the servo as the voltage will spike to 12+ volts if you are using a 12V battery. Safer if you are using 6v.

[Ron Olson]

Pat, this is an old trick that we used years ago, late `70's, early `80's in our R/C cars when ESC's were still in their infancy. We hooked them up to our rheostat-style speed controls to eliminate weight. Yeah, I'm that old! :D