HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Nov 18, 2011, 08:43 AM
I'm a pilot... 100 yrs to late
Thermalin's Avatar
USA, FL, Palm Harbor
Joined Jan 2005
3,423 Posts
Discussion
Regulate 7.2v down to 4.8v or 6v

I fly glow and my three 4.8v nimh batteries for my airborne units have gone bad. I would like to make a change to 2s 7.2v lipos for ease of use cheaper cost, ability to hold charge, etc.

I'm not electric knowledgable at all in terms of resistors or building something though I think i could with instructions.

Is there a simple, reliable and inexpensive voltage regulator that would allow me to use 2s lipos for normal 4.8 or 6v receiver/servo power.

Thanks,
Mike
Thermalin is offline Find More Posts by Thermalin
Reply With Quote
Sign up now
to remove ads between posts
Old Nov 18, 2011, 09:19 AM
Registered User
Joined Aug 2006
143 Posts
Quote:
Originally Posted by Thermalin View Post
I fly glow and my three 4.8v nimh batteries for my airborne units have gone bad. I would like to make a change to 2s 7.2v lipos for ease of use cheaper cost, ability to hold charge, etc.

I'm not electric knowledgable at all in terms of resistors or building something though I think i could with instructions.

Is there a simple, reliable and inexpensive voltage regulator that would allow me to use 2s lipos for normal 4.8 or 6v receiver/servo power.

Thanks,
Mike

The easiest way would be to get an external Swiching BEC, and they will let you run the servos at the voltages you want. They aren't too expensive. A search on here will give you more then enough info on them and how to select the model that fits your needs.
mpotter187 is offline Find More Posts by mpotter187
Reply With Quote
Old Nov 18, 2011, 09:22 AM
I'm a pilot... 100 yrs to late
Thermalin's Avatar
USA, FL, Palm Harbor
Joined Jan 2005
3,423 Posts
Thanks.. I'll take a look..

I do fly some electrics and I haven't given this much thought yet but what would prevent the use of a 30 or 40a ESC as the voltage regulator? It's already reducing reducing my 11.1 down to 4.8.
Thermalin is offline Find More Posts by Thermalin
Reply With Quote
Old Nov 18, 2011, 09:22 AM
Spoooooon!
TheTick's Avatar
San Fernando Valley, California, United States
Joined May 2003
3,786 Posts
If your servo's can handle 5cell nimh, the easiest way would be to use a Life rx pack and plug it in just like your nimh pack. All the advantages of a lipo rx pack with no need for a regulator.
TheTick is offline Find More Posts by TheTick
RCG Plus Member
Latest blog entry: Energic
Reply With Quote
Old Nov 18, 2011, 09:35 AM
I'm a pilot... 100 yrs to late
Thermalin's Avatar
USA, FL, Palm Harbor
Joined Jan 2005
3,423 Posts
Quote:
Originally Posted by TheTick View Post
If your servo's can handle 5cell nimh, the easiest way would be to use a Life rx pack and plug it in just like your nimh pack. All the advantages of a lipo rx pack with no need for a regulator.

Would need to pickup a life charger. Mine does NICD, NIMH and LIPO. My servos and reveivers are all over the board..some can and some can't and dont want to have to keep track and start moving components from plane to plane to get a 5v setup on this plane and 6+ on that plane, etc.


Can something like this be used with say a 2s 1000 or more mah lipo.
http://www.hobbyking.com/hobbyking/s...for_Lipo_.html
I get 4 flight safely from 1000mah nimh so I lets say 200 mah per flight...
From the link:
Turnigy 5A SBEC is an advanced switching DC-DC regulator which will supply a constant 5A. It works with 2 - 10 Cell Lipoly pack and supplies a constant 5 or 6v (via jumper) to your receiver and interference-free.
Thermalin is offline Find More Posts by Thermalin
Last edited by Thermalin; Nov 18, 2011 at 09:54 AM.
Reply With Quote
Old Nov 18, 2011, 12:17 PM
Spoooooon!
TheTick's Avatar
San Fernando Valley, California, United States
Joined May 2003
3,786 Posts
Oops..I just noticed that your posts says "4.8v or 6v". 6v refers to a 5 cell nimh pack which comes hot off the charger at over 7.2v. Most servo's are rated to handle 4.8-6v so you'll be fine with Life unless you have servo's that are rated at 4.8 only.

I've seen several people using those Turnigy bec's with no probs. If it's a valuable plane, I would probably go with something higher end. More importantly, make sure that the bec can handle the amp draw of a stalled or shorted servo. If you are only using a few small servo's 5amps should be ok. If you over amp the bec for a split second, your rx will brown out and you'll have no control while it resets.

If it's a larger plane, I would play it safe and get a 10amp bec or be even safer and use Life which eliminates the bec altogether. Hope this helps!
TheTick is offline Find More Posts by TheTick
RCG Plus Member
Latest blog entry: Energic
Reply With Quote
Old Nov 18, 2011, 01:10 PM
Registered User
Rugby, UK
Joined Feb 2007
851 Posts
Mike,

Here is a link to a test of UBECs I did some little time ago. Look at No3 on the list which is a Hobbywing UBEC designed specifally for use with 2cell or 3 cell lipos. It really was impressive both in terms of efficiency and conducted/radiated electrical interference.
No connection with Hobby wing but they must be wdely available in the US.

http://www.giantcod.co.uk/forum/view...it=ubec#p14319

Wayne
Wayne Giles is online now Find More Posts by Wayne Giles
Reply With Quote
Old Nov 18, 2011, 06:44 PM
I'm a pilot... 100 yrs to late
Thermalin's Avatar
USA, FL, Palm Harbor
Joined Jan 2005
3,423 Posts
I'll take some time to figure out my receivers and servos and see how much stuff can handle 6v... if most of it can i'll go with the life. for those that can't its 15 beans for the 8a ubec. not bad.

thanks..
Thermalin is offline Find More Posts by Thermalin
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Dumas 6V Motor on 7.2V flyingswede4 Scale Boats 12 Oct 13, 2011 10:25 PM
Sold Airtronics NH6N -1500S Ni-MH 7.2V Battery & Spektrum 8N-600 9.6V Nicad Battery Mikemynameis Aircraft - Electric - Batteries & Chargers (FS/W) 0 Apr 18, 2011 03:41 PM
For Sale Speed 400 2x 7.2v, 1x 6v, 1 Graupner 4.7"x4.7" w/ mount, Kontronik Rondo 400 Spd ctrl alaric Aircraft - Electric - Power Systems (FS/W) 0 Jan 04, 2009 03:48 PM
graupner 4.8V or 6V or 7.2V ? oferwain Power Systems 6 Feb 15, 2004 07:41 PM
Max amps for s400 4.8V 6V and 7.2V? Vonbaron Power Systems 0 Jul 12, 2003 02:23 PM