Previous in Forum: Strange Space Ships   Next in Forum: Nasa Nano Satellite Challenge
Close
Close
Close
18 comments
Power-User
India - Member - New Member Germany - Member - New Member France - Member - New Member Engineering Fields - Mechanical Engineering - New Member Popular Science - Weaponology - New Member Engineering Fields - Energy Engineering - New Member Hobbies - RC Aircraft - New Member

Join Date: Jun 2009
Location: India-maharashtra-kalyan
Posts: 119

Capacitor to Power Airplane

10/16/2010 3:38 AM

i want to use capacitor for powering my radio control airplane as power source. my motor is 4.5 volt,0.08-0.09amp DC motor.so can i use capacitor to power it instead of battery-pack.

__________________
Be an engineer not a degree holder!
Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Power-User
India - Member - New Member Engineering Fields - Electrical Engineering - New Member

Join Date: Apr 2010
Location: Asia/India
Posts: 365
Good Answers: 1
#1

Re: capacitor to power airplane

10/16/2010 3:56 AM

battery and capacitor are used for distinctly different purpose.How can you imagine a capacitor power your stuff as the capacitor discharge for very less time.Also exponentially decrease(V) to a dead end.

Reply Score 1 for Good Answer
Power-User
India - Member - New Member Germany - Member - New Member France - Member - New Member Engineering Fields - Mechanical Engineering - New Member Popular Science - Weaponology - New Member Engineering Fields - Energy Engineering - New Member Hobbies - RC Aircraft - New Member

Join Date: Jun 2009
Location: India-maharashtra-kalyan
Posts: 119
#2
In reply to #1

Re: capacitor to power airplane

10/16/2010 6:28 AM

ok thanks yar i am mechanical engineer but then also thanks for correcting me. if u know lightest battery with above configuration plz tell me.

__________________
Be an engineer not a degree holder!
Reply
Power-User

Join Date: Jun 2010
Posts: 348
Good Answers: 10
#4
In reply to #2

Re: capacitor to power airplane

10/16/2010 9:25 AM

Well, hithuanand gave you the perfect reply.

You claim to be mechanical try to be aeronautical a bit, change of wing span, its angle and lighter material for the frame is the requisite.

If you keep on worrying about battery weight how will my wait to get a free air ride in your plane will be over!

__________________
Knowledge sharing is a WIN-WIN situation
Reply
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9687
Good Answers: 467
#5
In reply to #4

Re: capacitor to power airplane

10/16/2010 9:31 AM

The OP didn't mention battery weight. A major advantage of capacitors is the very short re-charge time. This means (among other things) that it would be possible to distribute the load within the plane, and re-charge in situ, rather than removing and replacing the pack.

__________________
"Love justice, you who rule the world" - Dante Alighieri
Reply
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9687
Good Answers: 467
#3

Re: capacitor to power airplane

10/16/2010 9:15 AM

It may be possible using ultracapacitors with appropriate power management circuitry (I haven't looked into the details).

I suggest you read some of the links found by this search:

http://www.google.co.uk/search?q=ultracapacitor+battery+replacement

__________________
"Love justice, you who rule the world" - Dante Alighieri
Reply
2
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 15111
Good Answers: 936
#6
In reply to #3

Re: capacitor to power airplane

10/16/2010 12:33 PM

Ultracapacitors have a higher energy density than conventional capacitors but still lower than any battery. Because they have a considerably higher power density, they can make a system much more efficient with strategic utilization. There is also a problem using any capacitor instead of a battery with the stability of the voltage. When half of the energy available in a battery has been used, the voltage across the battery is still close to the original voltage. With any capacitor the voltage will have dropped to about 0.707 (1/√2) of the original voltage.

Since the power usage to operate a remote plane will likely be very constant, the total energy available to be drawn for the amount of mass carried will be more important. So I'd stay with the choice of a battery.

(Image acquired from a Wikipedia article on Ultracapacitors.)

__________________
"Don't disturb my circles." translation of Archimedes last words
Reply Good Answer (Score 2)
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9687
Good Answers: 467
#7
In reply to #6

Re: capacitor to power airplane

10/16/2010 5:49 PM

You're right - as I said, I haven't looked into the details (just didn't want to dismiss it out of hand).

The voltage drop vs. depletion shouldn't be a consideration tho', because with a decent power control circuit (equally applicable to battery supplied systems), the load should be fed with adequate voltage and current until the power source is (at least 80%) depleted.

[This is going to get me started about the crap power management system in an HP camera I had, which seemed to be totally voltage dependent, and would not even power the camera for a single shot with new alkaline batteries].

__________________
"Love justice, you who rule the world" - Dante Alighieri
Reply Score 1 for Good Answer
Power-User

Join Date: Jan 2007
Location: spain N38 39' E 00 3' and uk N52 14' W 00 54'
Posts: 247
Good Answers: 3
#11
In reply to #6

Re: capacitor to power airplane

10/17/2010 8:49 AM

In order to overcome the voltage drop problem, one company has arranged multiple ultracapacitors that kick in , in sequence, to maintain the voltage as the current is drained.

__________________
duikerbok
Reply
Guru
Canada - Member - Specialized in power electronics

Join Date: Feb 2008
Location: Montreal, Canada.
Posts: 1357
Good Answers: 80
#13
In reply to #6

Re: capacitor to power airplane

10/17/2010 2:01 PM

Redfred GA!

I was wondering where we could find such a graph. I will forward this to a friend who does airplane modeling.

Thank you.

__________________
Experienced is earned, common sense is taught, both are rare essentials of life.
Reply
Guru

Join Date: Apr 2007
Location: Hyderabad, India
Posts: 596
Good Answers: 12
#17
In reply to #6

Re: capacitor to power airplane

10/17/2010 11:50 PM

Not just Good, a Great Answer!

__________________
Subramanyam
Reply
Guru

Join Date: Sep 2007
Location: Defreestville, NY
Posts: 1072
Good Answers: 87
#8

Re: Capacitor to Power Airplane

10/16/2010 9:58 PM

Flying a plane on less than 1/2 watt of power is very impressive. Are you sure those numbers are right?

__________________
Charlie don't surf.
Reply
3
Guru
Hobbies - HAM Radio - New Member United Kingdom - Big Ben - New Member Fans of Old Computers - Altair 8800 - New Member Canada - Member - New Member

Join Date: Jun 2006
Location: Toronto
Posts: 3968
Good Answers: 119
#9

Re: Capacitor to Power Airplane

10/16/2010 10:29 PM

No matter what you do, the capacitor will never reach the energy density of a battery.

A capacitor can be far far faster than a battery in charge or discharge though, whihc leads to some applications that need surge power.

A capacitor is like a spring, and a battery is like a weight on a long rope rope

__________________
Per Ardua Ad Astra
Reply Good Answer (Score 3)
Commentator

Join Date: Aug 2010
Location: VA
Posts: 84
Good Answers: 4
#10

Re: Capacitor to Power Airplane

10/17/2010 8:20 AM

Consider a LIPO battery, they are flown every day -models- and even have flown real prototype aircraft, fast recharge and light with the smaller ones in the GRAM weight range. Best weight versus power and voltage ( 3.7 nominal per cell). Woody

__________________
Life is short, eat your dessert first .......In theory there is no difference between theory and practice. In practice there is. Yogi Berra
Reply
Anonymous Poster
#12

Re: Capacitor to Power Airplane

10/17/2010 12:53 PM

I recently ordered two LI-80 lithuim batteries for my hp digital t-100 camera, hp wanted 40.00 us for this 650 ma battery, I inputed the number in Amazon and found several sources, the one I ordered from hong kong was 1.85 us I ordered two under the dollar shipping promotion figuring what did I have to lose, the batteries came in 10 day's and they were not only a match but they were 900 ma, go figure, I may order ten or twenty to build bricks that I can use in my radio controlled airplane projects, I just looked up the battery in my cell phone and came up with a 4.50 us match from aforementioned web site, don't get rooked by this money hog industry, look up the stuff yourself... when I started radio controlled electrics they were heavy and underpowered, now if you look ant nitroplanes.com the brushless dc motors are incredible for the size and ducted fans are the new power source for jet radio lawn darts. the new 2.5 ghrtz radios are so cheap you can have one for each plane.

Sincerely
Mitch, retired peugeot mech

Reply
Guru
United Kingdom - Member - Not a New Member Hobbies - Musician - New Member Hobbies - Fishing - New Member

Join Date: May 2006
Location: Reading, Berkshire, UK. Going under cover.
Posts: 9687
Good Answers: 467
#14
In reply to #12

Re: Capacitor to Power Airplane

10/17/2010 5:20 PM

Lesson for all - DON'T buy from the camera (or whatever) manufacturer. Similar differential trying to buy Canon or Nikon batteries.

Check out the battery type, and buy from a (trustworthy) distributor for about 5% of the equipment OM price.

__________________
"Love justice, you who rule the world" - Dante Alighieri
Reply
Commentator

Join Date: Aug 2010
Location: VA
Posts: 84
Good Answers: 4
#15

Re: Capacitor to Power Airplane

10/17/2010 7:46 PM

Its possible that the power stated is for the control, i.e. radio; and that the engine is fuel powered. My electric planes are light and use 11.1 volts at up to 5-10 amps for 10 minutes. Woody

__________________
Life is short, eat your dessert first .......In theory there is no difference between theory and practice. In practice there is. Yogi Berra
Reply
Guru

Join Date: Feb 2006
Posts: 1763
Good Answers: 6
#16

Re: Capacitor to Power Airplane

10/17/2010 8:34 PM

Read

circuit-could-swap-ultracapacitors-for-batteries

Latest reading on super-capacitor.

Still it is for instantaneous power not a continuous source of electrical power.

Reply
Power-User
India - Member - New Member Germany - Member - New Member France - Member - New Member Engineering Fields - Mechanical Engineering - New Member Popular Science - Weaponology - New Member Engineering Fields - Energy Engineering - New Member Hobbies - RC Aircraft - New Member

Join Date: Jun 2009
Location: India-maharashtra-kalyan
Posts: 119
#18

Re: Capacitor to Power Airplane

10/18/2010 5:02 AM

thanks all above people who gave info about capacitor & ultracapacitor is new subject for me.Thanks once again for improving my knowledge.

__________________
Be an engineer not a degree holder!
Reply Score 1 for Good Answer
Reply to Forum Thread 18 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

Anonymous Poster (1); aurizon (1); duikerbok (1); Haajee (1); hithuanand (1); JohnDG (4); kvsubramanyam (1); marcot (1); mountk2 (1); rajeshbhanushali123 (2); redfred (1); stevem (1); waldig (2)

Previous in Forum: Strange Space Ships   Next in Forum: Nasa Nano Satellite Challenge

Advertisement