Before I burn up another one of these things, can I power a camera and transmitter off of a 3S LiPo battery? The specs for the camera say 9 - 12.6v and the specs for the transmitter say 8 - 12v.
I tried using a 3S on another camera and transmitter and wound up with a small cloud of smoke and no video. It is my understanding that the 3S produces 11.1v which should be fine. As for AMP's, the devices will only draw what they need correct?
Figured I would ask the community before I fry this new FPV system that just arrived (I have another on order just in case).
Thank you in advance!
Replies
So i am trying to use a single 4s battery to run my fpv setup however my camera only needs 12 volts. how do i come off the balance lead and only use 3s worth?
Hey guys, does it make sense that I could be running my 12V camera and VTx off a 2S? It seems to work fine?
I'm using this camera:
http://www.hobbyking.com/hobbyking/store/__21324__1_3_inch_SONY_CCD...
And this VTx:
http://www.hobbyking.com/hobbyking/store/__15295__5_8g_200mw_FPV_Wi...
And I was powering both with a 2S800 battery. Like I say, seems to work fine. But would I be losing anything?
Also, what do you think about running these on the same 2S battery that would be powering the APM and servos on a big heli? Not the same battery as the motor, but just the avionics and servos. I did pick up one of these just on a lark but haven't used it yet:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=...
There are some goofy 5 volt cameras and video tx's out there, but this works just fine. If you need to go the extra mile, get (whatever you call it) that takes in your 10-13 volts and just outputs 12.
I have used 3S lipos directly to power camera and Tx a number of times without any smoke issues. One thing nobody has mentioned is brown-out performance. Your main battery pack voltage is going up and down a lot in direct proportion to your throttle stick. Although you may land with >11V you will definitely have excursions much lower than that. I happen to have a nice power supply and tested my particular Tx and camera combos. I had one set that would brown out at ~8.5V which was probably fine but another one worked well down to 6V and then carried on in wobbly black and white down below 5V. Both were 12V devices. If you cannot find a good power supply to test with, record your video while running your battery down as low as you normally dare and then with the quad (or whatever) on the ground give it a few short full bursts of throttle and check that the video stays on.
Luckily these are still analogue devices and they power up quickly once voltage returns. There would be nothing worse than losing video while still flying just due to brown-out.
As far as a UBEC is concerned I normally use CastleCreations 10A peak BECs. While they work great in airplanes, they need to be away from the APM. I had one hexa noticeably twitching in one axis when I relocated the BEC closer to the APM, moving it cured the problem. A linear regulator should not have this issue as there is no switching going on.
What I found works best for my FPV quads and airplanes:
A 3s 1300 / 12v direct to FPV cam and transmitter, and a Y split to a UBEC or SBEC with 5 V jumper setting for the simple OSD/Telemetry and Transmitter.
Then a separate power source going to the ESC(s).
Hope this helps.
All the best.
Daniel
Short answer is yes you can. i do it myself on 2 of my FPV crafts. No need to complicate issues and make more potential failure spots in your circuit , not to mention the extra interference from any more electronic voltage switchers.
Happy flying.
No need to complicate matters. One battery, if a 3S, works fine. As has been said, with a correctly operating charger, the fully charged 3S should not exceed 12.6 V and that won't stay there for long. LiPo's have a relatively flat discharge curve except at beginning and end. Your battery will be at 12V before you know it. If you saw magic smoke, more than likely you reversed polarity somewhere. If you are worried about video noise, add a common mode filter. Want to read more, go to FPV Labs...
I use a class b lipo to power my transmitter and camera in parralel, i do not bother with a diode after a fresh charge ect because the voltage drops instantly to around 12V
these things have built in regulators so its not a big deal is its 12.6v
Now you have a diode there is no reason to change them out, but for future reference, the things will run fine.
However it also depends on battery size because that determines the voltage drop, i use a 1000mah but a 2200mah would likely not drop for a while and cause problems.
http://www.hobbyking.com/hobbyking/store/__18787__12V_2_5A_UBEC_2_5...
If the device says 12V then 3S is fine. A fresh LiPO straight from the charger is 12.6V and settles at about 12.4V after resting for a short while. And there is usually at least a +-10% headroom when it comes to electronics and voltages. And most will work at even larger discrepancies. And during usage the LiPO battery will only stay at 12.xxV for a short time before it starts to drop. So in fact when you are using 3S on your device, it is more important to know that it will actually operate at a lower then 12V (~11V) most of the time.
But.. Know that while a regular wall socket power supply only delivers a couple of amps max, if something goes wrong a LiPO battery will deliver hundreds of ampers, and completely destroy the electronics.