Lipoly Battery on Glow Powered Helicopter using Linear Regulator to drop the Voltage

[lazy-b]

Guys: Have you tried using 2 Cell Lipoly Battery to powered the Receiver and 5 Digital Servo for your Glow Helicopter, using a Linear Voltage Regulator to drop the 7.2 Volts to 5 Volts?

Plan to use 3 terminal Linear Regulator LX8383 7.5 Amps Low Dropout Positive Regulator, this look much simpler to make just need a heatsink, and its less noise, compare to SWITCHING Regulator.

Been doing this for Car/Boat/Plane using LM7805, but have not try it on Helicopter.

I am just not sure if this LX8383 can handle the current surge of 5 Digital Servo?

or maybe you can recommend a better regulator(small/light/cheap)? its just so happen that this LX8383 is available here.

[pbunn]

Problem is, a large linear regulator will waste energy. All of the dropped voltage will be lost as heat. That is a considerable amount - (7.2-5) (current) and a heat sink to get rid of this energy (heat) will be heavy)

At 5 amps you will be disapating (2.2) (5) or 11 watts and that is going to take a sizable heatsink. More current will take an even larger one.

The weight of the heatsink may take away the advantage of the LIPO.

[Acetronics]

Hi,Ellion

a Happy new year to your whole family !!!

Have a look to MIC 29502 ( 5A ) or 29752 ( 7.5 A ) ( I get 'em from Farnell or Radiospares ... ) you can also use the en. pin as a security switch ( open sw. = Reg ON )

If interested ... I can mail you scheme, PCB and placement !!! That's not the first I've built for friends

Alain

[lazy-b]

pbunn, Yes.....I am aware of the in-efficiency of a linear regulator....its just so happen I have lots of Lithium-ion battery 1400MAH I can make a 2S3P this give an equivant of 7.2 Volts 4200 MAH, thats a lots of Reserved Battery Capacity......Regarding Heatsink, planing to use a very thin sheets of aluminuum (Large surface area for faster heat disipation).

Alain, Happy New Year too....

Thats Great.....Please email it to me, this save me the proto-typing and experimenting......and I can buy anything whats on Farnell or RS-Components........One thing I hate making a Switching Regulator is trying to source those INDUCTOR.....I hope this Switching Regulator do not make a noise the will effect the receiver.

I have this VICOR DC-DC converter its 12 Volts input and 5 Volts 10 AMPS output, it has a wide range input voltage from 10 Volts to 20 Volts, its ideal to use 4 pcs Lithium-Ion......I am hesitate to use it on my Helicopter due to electrical noise produce by switchig regulator.

I have this experience of Switching Regulator interference with receiver, I have this FUTABA GH-1 Glow Igniter, everytime I turn on the Glow Igniter, all Servo get Jitter and go wild.

Ellion