Where do you draw the power from for your onboard FPV Tx?

mmurfitt

mmurfitt

Member
Hi,
I have a F550 and am in the process of mounting the FPV Tx, however on the back of the Tx box it says the power supply should be between 7-12v. I was going to solder the power for the Tx directly to where the Lipo cable supplies the F550 with power, but I guess I can't do that now.
Have I understood this correctly, or am I being over cautious?
I've attached a photo of the back of the box to show what I'm talking about..
View attachment 6747

(Apologies if this is the second post here, I could have sworn I'd already wrote and posted this, but I can't find it anywhere..)
 

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Kilby

Kilby

Active Member
That vtx (as do most) will only support up to 12v power, so if you use a 4s flight battery, you will have to either...

1. use a separate 3s battery for video gear (that's what I do)
2. step the 4s power down to 12 volts with a regulator of some kind.

If you use a 3s flight battery, just tap into your main power source, but you won't be able to use a 4s ever if you do that... it will probably blow your vTX.

-Terry
 

mmurfitt

mmurfitt

Member
Thanks Terry.
I use 4s 5000mAh batteries, so I guess I'm going to have to figure out how to step down the power to 12v I guess.

I wonder if there's a BEC which will do this...hmmm, best get googling.. :)
 





DesJardins

DesJardins

Member
mmurfitt said:
This is my fall back, to have a separate battery pack, but I want to try and keep the weight down, so I'll do this if this is the best option.
Click to expand...
Right on, keep in mind the little 460mAh lipo weighs in at only 43g, the CC pro BEC weighs in at 29g.

Saves about .5oz if that weight savings is worth it, the little lipos are $10bucks from ReadymadeRC
 
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Kilby

Kilby

Active Member
You also have the piece if mind that your not going to lose you fpv if you run your flight battery to low. That's thenin reason I run a second battery. Plus you can continue to run the fpv gear while you switch out flight batteries. That's a big help if you have an OSD with GPS that needs to lock sats.
 

kloner

kloner

Aerial DP
you don't usually want to run a seperate battery..... it has to get a super clean power supply, theres a few great options. one is the TBS core, It has two changeable switching supplies with filters so you can draw on the flight packs. a 4s battery will be on fire before theres not enough energy to power a 12v camera from over draning it. this one pictured will go down to 7v, that's like 1.7v a cell. This one also has an optional current sensor to use with it's built in osd. with sensor is around $85
http://www.team-blacksheep.com/products/product:14
http://www.getfpv.com/team-black-sheep/team-blacksheep-core.html


the other and i feel better option is from dpcav. I've seen this for sale at alot of the other fpv dealers but there always out of stock, i think dpcav makes em for everybody
http://www.dpcav.com/xcart/Power-Supply-Filter-L-C-Type.html
http://www.dpcav.com/xcart/Adjustable-Voltage-Regulator-1-35V-Step-Down.html
as long as your camera if using one is the same voltage, one of those will do a watt and a camera but no osd.

Either of these are a cleaner power supply than even a plain battery. that second system is no joke, i got this on my zII and when i got a high gain antenna pointed at it, the signal is like watching cable tv
 
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DesJardins

DesJardins

Member
One thing I have learned is there are many ways to do these things but I am interested in why a seperate lipo is dirty or is the lipo power dirty period and the filter could be used in either application?

Using OSD to tell the battery life is great but if it fails it fails :-/

I'm learning a grip very quickly!
 
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kloner

kloner

Aerial DP
any power unfiltered is dirtier than filtered power, no matter from a battery, wall, whatever. for me, every oz is big, when were adding a thousand mah, i want it in my gas tank and i'm gonna fly it. The video cam and tx draw .5 amps..... whole flight....... that's like a few leds. if you use a seperate pack your landing with an empty flight pack and a full video pack.... extra weight not needed. Theres a thread about this at fpv lab, one of them 800 posts ones, anybody into this stuff can tell the new guy by the seperate pack for video..... just a fact. Filters, even if you want the seperate packs are what you want...... it makes less flickers, junk, etc. if you got immersion, it's all built in and it doesn't need squat but 4s or less straight to a distro board, gone over a mile on 5.8 like that with 3s motors to top it off. livin life on the edge baby
 


kloner

kloner

Aerial DP
yes, any pad. if you don't have a board cam, even less reason. don't try to power the gopro through the back with one of them rear plugs. i had that on the other day when i crashed, almost think it does something to the core cause it was really hot fast.
 

Kilby

Kilby

Active Member
kloner said:
Theres a thread about this at fpv lab, one of them 800 posts ones, anybody into this stuff can tell the new guy by the seperate pack for video..... just a fact.
Click to expand...

I guess that I'm a "new guy" that's been flying FPV for over 2 years now with a second pack.
 

kloner

kloner

Aerial DP
yo just don't follow modern fpv setup philosphy. do you run a stretched out frame to seperate stuff? is there a filter and a step up/down on the seperate pack? the problem lies that you want filtered constant power, seperate pack by itself isn't that, with filters and reg is but then you don't need the pack hence guys that are into it ditch the extra pack.

Trappy, Sassen, sentry, all them guys don't run a second pack... it is part of the TBS setup philosophy. The other thing it does is never over powers it at 12.6 and never goes down below 12v like a 3s that runs down to 11.1 volt. Alot of them vtx's only work at exactly 12v

heres a refresher
http://fpvlab.com/forums/showthread.php?265-Team-BlackSheep-system-setup-philosophies&highlight=pack

There is a lot of misinformation being spread in FPV forums, so I feel the need to put all of the things that have been tried & tested in countless environments and situations by myself and other experienced FPV pilots into a nice little list. Follow these simple rules and regardless of what everyone else is saying, you will have success in FPV. This does not mean that not following this list means your FPV system will not work at all, but it does mean it will not work as safely, as reliably and as well.

Before we get to the list, let me just point out that while these points reduce the possibility of technical failures resulting in the loss of your aircraft, they do not account for stupidity on behalf of the pilot. If you want to fly into a tree and you consequently lose your plane, well, you shouldn't have flown into the tree.

  • Start with the bare essentials and add equipment one step at a time. after each new equipment was added do proper range- and stress tests.
  • Do not fly with a video system that is capable of outperforming your R/C system in terms of range
  • Do not fly with a R/C frequency higher than the video frequency (e.g. 2.4GHz R/C, 900MHz video).
  • Monitor the vitals of your plane (R/C and battery). Flying with a digital link without RSSI is dangerous.
  • Do not use 2.4GHz R/C unless you fly well within its range limits, in noise-free environments and always within LOS. since this is most likely never the case, it is recommended to not use 2.4GHz R/C systems.
  • Do not fly at the limits of video. if you see noise in your picture, turn around and buy a higher-gain antenna before going out further.
  • Shielded wires or twisted cables only. anything else picks up RF and can cause problems
  • When using powerful R/C transmitters, make sure your ground station equipment is properly shielded
  • Adding RTH to an unreliable system does not increase the chances of getting your plane back. Work on making your system reliable without RTH first, then add RTH as an additional safety measure if you must. At this point you will most likely realize RTH is not required.
  • Avoid powering the VTx directly. step-up or step-down the voltage and provide a constant level of power to your VTx, otherwise make sure your VTx runs reliably until the battery dies. Try to avoid 12V VTx on 3S systems.
  • Do not power your camera directly unless it works along the complete voltage range of your battery. step-up or step-down the voltage and provide a constant level of power to your camera. make sure your camera runs until your battery dies.
  • A single battery system is safer. 2 batteries in parallel to mitigate further sources of failure. reverse current protection is recommended, but usually not feasible
  • For maximum video range, use 2.4GHz video with high-gain antennas
  • When flying with R/C buddies that fly on 2.4GHz, or when flying in cities, it is perfectly possible to use 2.4GHz video provided you stick to the channels that do not lie in their band (ch5 & 8 for lawmate)
  • Do not use diversity as a replacement for pointing your antennas. diversity should be used to mitigate polarization issues
  • Improving the antenna gain on the receiver end is better than increasing the output power (except in RF-noisy areas). 500mW is plenty of power, more tx power causes more issues with RF on your plane.
  • Do not buy the cheapest equipment unless it is proven to work reliably (e.g. capacitors falling off, multitudes of bugfix firmware updates, community hacks and mods are a good indicator of poor quality and something you do NOT want to buy). Saving $50 is simply not worth losing your plane.
 


DesJardins

DesJardins

Member
All valuable info for sure, this is the stuff I'm happy to see for sure.

I guess the item that rubbed me the wrong way in the TBS section was when I asked about how important the core is to the frame and set-up but instantly was asked about $$$$ and if the cash isn't there I shouldn't be flying FPV.... shocked on that one!

That doesn't make me want to send my hard earned cash to anyone. The implication was wild but I brushed it off as I learned long ago on that stuff being taken out of context. All in all, I'm a guy who loves having nice **** but I never bought a Goblin as I couldn't fly like Bert so stuck with my 500EFL pro which is still an amazing heli.

anywho, I appreciate all the MR/FPV insight as I have learned a grip from you Kloner and will continue to learn as time goes on.
Hell I have had my FPV gear for 2 days now ;-)

My wife's family is all in Orange County so we'll be heading out early November if your up to show me the long range FPV gear!
 
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kloner

kloner

Aerial DP
yea, i yelled at him for that,,, was like wtf?

i bet if we met mr dji or mr align we wouldn't want to either but hey, if the stuffs good i'm in. He's just pissed cause my grandpa shot at his grandpa, hahaha

dad_ace_pilot-800x635-_795.jpg
 

DesJardins

DesJardins

Member
LMAO, my grandpa took a few shots too!

I'm glad somebody else saw that and shared similar thoughts on it.
 
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