a little help??

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earthwormjim
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a little help??

Post by earthwormjim » Thu Jan 31, 2013 3:57 pm

Hello techno geeks.
I am a mere mortal,and as such am having difficulty with this problem...
I have a little quadcopter,I have mounted a small camera and transmitter to it.At the moment,i m having to use two 1s batteries,as the motors produce alot of interferance with the transmitter.Could I power both circuits with one battery,and clean up the power going to the tx circuit?
What about a 3.3v regulator,with a cap?
If so what cap would you suggest I try.Specifics on the board are scarce i'm afraid.
Thanks chaps. :)
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BeligerAnt
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Re: a little help??

Post by BeligerAnt » Thu Jan 31, 2013 8:15 pm

Hi Jim, you don't really need a regulator, you need a filter!
Capacitors will help, but you need some series impedance for them to work against. Resistors would work, but you are limited to how much resistance you can use by the DC voltage drop. The better solution is to use an inductor which provides AC impedance but little DC resistance.

Capacitance on its own might help, but you would probably need a range of values, say 10uF, 1uF, 100nF (0.1uF) and maybe even 10nF all in parallel. Bigger values help with lower frequencies and smaller values help with the higher frequencies.

If the camera and/or transmitter needs 3.3V you might need a regulator to avoid frying them with a freshly charged (4.2V) battery, but since you are already running directly off 2 x 1S batteries I guess the camera & transmitter can handle it.

Hope this helps
Gary, Team BeligerAnt

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earthwormjim
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Re: a little help??

Post by earthwormjim » Thu Jan 31, 2013 9:03 pm

Perfect.Thanks Gary.
The tx runs with 3 - 5v.
I will have a play,thanks for the info. :)
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Re: a little help??

Post by BeligerAnt » Thu Jan 31, 2013 10:29 pm

Hi Jim
To avoid messing about with inductors (can get complicated!) try this:
Put capacitors across the power pins of the speed controller (each one if you have several) and across the power pins of the transmitter.
Then wire each one back to the battery separately. This is the important bit. Don't daisy-chain one part onto another.
This is probably the best you can get without messing about with complicated filters.
Gary, Team BeligerAnt

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