LibrePilot Forum
General Category => General Discussion => Topic started by: Daxo on March 04, 2016, 05:43:59 pm
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Hi guyz, as title says I'm curious does anyone happen to know what's the CC3D current draw?
Asking as I found some 5v 500mA bec I've never used, so wondering will it do to power just the cc3d and is there any difference in current draw between the CC3D/CC3D Atom/ CC3D Nano?
Appreciated!
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All CC3D* share the same schematic so should be the same current draw.
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Thanks f5soh, appreciated!
I'm guessing it shouldn't be more than 100mA.
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Just did a quick search for cheap step down for powering only the CC3D and D4R II receiver, I know the receiver draws 60mA but not sure about the FC.
A guy on FB said he just measured his cc3d at 50mA. Not certain is there much more difference in current draw of fc in flight or while being just powered on the desk.
If his measurement is correct, 110mA for fc and rx, ideally 180mA, but I'm hoping 150mA would suffice.
I wonder if this would do the trick for powering the fc and rx? http://www.digikey.com/product-detail/en/LP2985-50DBVR/296-20717-1-ND/1169352
Edit:
Actually, for 2$ more, cant go wrong with this http://www.digikey.com/product-detail/en/TPS62112RSAT/296-19717-1-ND/1045155
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I wonder if this would do the trick for powering the fc and rx? http://www.digikey.com/product-detail/en/LP2985-50DBVR/296-20717-1-ND/1169352
How about the power dissipation using a small package like that ?
Example: input = 12.6V output = 5V @100mA
PD needed = (12.6-5)*0.1 = 0.76W
From datasheet:
PD = (TJ (max) – TA )/θ JA = (150 - 20)/206 = 0.63W
Assuming the ambient temperature is 20°C
For 40°C the PD capability is lowered to 0,53W
And we are talking about limits, at this stage the regulator is close to shutdown i think...
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The 2nd one could do the trick? It isn't a lot bigger either.
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Do you take all components in account ?
This last is a "DC/DC switching regulator", that mean the is a coil somewhere.
Just put a step down, popolu like and stop reinvent the wheel :)
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Yeah, polulu 5v step down is probably the best a way to do it, but that means that i'll need to redesign my pcb with inner slot with polulu reg dimensions and use Castellated Mounting Holes for 'docking'.
Was hoping to find a simple way for powering FC and RX from board, if possible.
I'll be receiving first prototypes soon so i'll be able to show what I'm working on. The nature of the solution is such that user would greatly benefit by having inner FC/rx powering
Edit;
worth mentioning, it's nothing complex or complicated, quite the opposite. It's what it does for the user, not about the pcb it self.
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Ah... looking for something integrated to frame...
What appends if user want to add GPS and more ?
What appends if user use 6S battery ?
You should start with something rated to 1A, switching regulator.
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gps, BT and other stuff would certainly increase the draw a lot and 6S is not something I'm looking for.
Set for 3-4s, that's it. Yeah I think 1A would be the best. In the end, I'll probably make a 'docking' for polulu reg as mentioned earlier.
The reason for 3-4s is heat, and I need to test it for 4s to be sure. I'll share more when I get a proto, you'll see what I mean.
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I am using this one 1A 5V Pololu https://www.pololu.com/product/2831
To power flight controller, gps, receiver, video transmitter, camera. I measured un-armed (in rest) around ~610mA current of the whole system, but that includes also powering 4x KISS ESCs.
So 1A should be way more than plenty. You can also measure with multi-meter even basic ones can measure current.
Be sure to solder it correctly, because it may give 12V if ground is not soldered, but that's like almost any regulator.