Page 1 of 2 12 LastLast
Results 1 to 10 of 11

Thread: TBS Core 25 for QAV250

  1. #1
    Navigator
    Join Date
    Nov 2013
    Location
    Scottsdale,AZ
    Posts
    51

    TBS Core 25 for QAV250

    Is the TBS Core 25 too small for the QAV250 running 4s?

    I'm building a 250 running 4s and the Lumenier RX2204-14 motor. Rough math say the max current on that setup is 48 amps, well outside the range of the Core 25.

    However, I've seen several setups with people using it... do they just not route motor current through it?

  2. #2
    Pilot raumagent's Avatar
    Join Date
    Aug 2014
    Location
    Germany
    Posts
    300
    The PNP25 is no good choice for your setup, get yourself a PNP50 and you're fine.

  3. #3
    Navigator adamky1's Avatar
    Join Date
    Dec 2014
    Location
    Louisville, Kentucky USA
    Posts
    204
    You pretty much answered your own question. I'm running a PNP25 on my 4S setup, but I am only using it for the power filtering, power regulators, and OSD. I'm not using the current monitoring function. It's so compact and simplifies wiring so much that I think its worth it even without the current monitoring.
    Last edited by adamky1; 21st December 2015 at 11:44 PM.

  4. #4
    Navigator
    Join Date
    Feb 2015
    Posts
    9
    Late reply but, No. The wiring on the PNP25 is too small for most 4S systems. raumagent is right. PNP50 and you will be able to use all but the current monitoring. A 4S system draws typically 60-100a.

    The pnp25 is really only usable on small fixed wings.

  5. #5
    Navigator adamky1's Avatar
    Join Date
    Dec 2014
    Location
    Louisville, Kentucky USA
    Posts
    204
    Quote Originally Posted by InocentRoadkill View Post
    Late reply but, No. The wiring on the PNP25 is too small for most 4S systems. raumagent is right. PNP50 and you will be able to use all but the current monitoring. A 4S system draws typically 60-100a.

    The pnp25 is really only usable on small fixed wings.
    If you're not going to be using the current monitoring function, I don't see how a PNP50 would be any better than a PNP25..?

  6. #6
    Navigator
    Join Date
    Feb 2015
    Posts
    9
    Because the PNP25 uses smaller gauge wire and JST connectors and the PNP50 uses thicker wire and XT60 adapters.

    JST connectors are only rated for 3A BTW...

    http://www.jst-mfg.com/product/detail_e.php?series=521

  7. #7
    Navigator adamky1's Avatar
    Join Date
    Dec 2014
    Location
    Louisville, Kentucky USA
    Posts
    204
    Quote Originally Posted by InocentRoadkill View Post
    Because the PNP25 uses smaller gauge wire and JST connectors and the PNP50 uses thicker wire and XT60 adapters.

    JST connectors are only rated for 3A BTW...

    http://www.jst-mfg.com/product/detail_e.php?series=521
    I don't think you understand what "not using the current sensor" means. If you are using one of these without the current sensor, that means you only have one power and one ground feeding the unit. The only things being powered by the PNP25 in this case are your FPV camera and your VTX. That's it.

    If you're plugging it inline and the power for your ESCs/motors/whatever, are all running through it, then you are still using the current sensor. Yes, you are greatly exceeding its current rating, so it would be very dumb to do that on a 4S setup and even most 3S setups. Personally, I wouldn't even recommend using a PNP50 on a 4S setup because like you said, the total current draw can well exceed 50A. That means that the wiring and internal circuitry are only designed for up to 50A and things could easily overheat to the point of burning up if you're trying to pull 60-100A of current through it.


    I've been running the PNP25 for a while now on my 4S setup. I ONLY use it for the regulated/filtered power and OSD. My PNP25 only has a power wire and ground wire feeding it off of my PDB. The other two wires were removed. It is used as an OSD and power regulator/filter ONLY. The motors, ESCs, and LEDs are all powered directly from the PDB.

    My camera says it draws a MAX of 150mA: http://www.readymaderc.com/store/ind...oducts_id=1405
    My VTX says it draws 220mA: http://www.getfpv.com/lumenier-tx5g6...ansmitter.html

    So unless the TBS unit itself draws over 2A, you're going to be nowhere near 3A.

    Pictures for further illustration:
    Last edited by adamky1; 7th January 2016 at 08:44 PM.

  8. #8
    Navigator
    Join Date
    Feb 2015
    Posts
    9
    Lol, You don't even need a filter if you use the regulator you already have installed to power your cam and VTX. You can't measure the battery power if you use a regulator to supply the power to the core, so the only function you're getting is the timer. (That is if the timer works, I think it's set to start when current draw starts...)
    So basically you're using one of the functions of the pnp25 unit why even use it?

    You could try to solder it directly to the PDB and it would make some sense because it would monitor the battery voltage at least. The wiring might be too thin to handle the amperage or it might be okay since you're not using the current sensor function.
    Last edited by InocentRoadkill; 7th January 2016 at 09:09 PM.

  9. #9
    Navigator adamky1's Avatar
    Join Date
    Dec 2014
    Location
    Louisville, Kentucky USA
    Posts
    204
    Quote Originally Posted by InocentRoadkill View Post
    Lol, You don't even need a filter if you use the regulator you already have installed to power your cam and VTX. You can't measure the battery power if you use a regulator to supply the power to the core, so the only function you're getting is the timer. (That is if the timer works, I think it's set to start when current draw starts...)
    So basically you're using one of the functions of the pnp25 unit why even use it?

    You could try to solder it directly to the PDB and it would make some sense because it would monitor the battery voltage at least. The wiring might be too thin to handle the amperage or it might be okay since you're not using the current sensor function.
    Where in my post did I say that I was feeding the PNP with the 5V regulator that you're referring to? Not only would that be completely pointless, but as noted on their webpage, the PNP25 is designed to run on 2S-10S batteries (7.4V- 37V): http://www.team-blacksheep.com/products/prod:core_pnp25. 5V might not even be enough to power it up.
    Here is a direct quote from my last post:
    Quote Originally Posted by adamky1 View Post
    My PNP25 only has a power wire and ground wire feeding it off of my PDB.
    The 5V regulator does NOT feed power to the PNP25. The PNP gets it's power directly from the PDB. The separate 5V regulator (which is also connected directly to the PDB) is only providing power to my CC3D and D4R-ii. That was added after I read on another forum that the regulators built into the PNP might not be able to handle powering the camera + VTX + D4R-ii + CC3D. Rather than take the chance that it might not handle the load, I added the 5v regulator from my bin of spare parts.

    My VTX has an operational range of 7-19V as stated in the link that I posted. So, I couldn't feed it with the small 5V regulator, and even if that was somehow possible, I would still need an OSD. So rather than install a separate 12V regulator (or alternatively, a LC filter) as well as a separate OSD, I decided to use the PNP 25 because it provides all of those functions in a small package with less cluttered wiring. I have previously run a LC filter and a Hobby King E-OSD when I was on 3S and it made for a cluttered mess of wires. It's so much simpler and clean using the PNP.

    Also, the timer kicks on as soon as you give power to the PNP. It doesn't use the current sensor to trigger it. So, I agree that it's not all that helpful. But, since I can see my voltage via the OSD, the timer is really not necessary anyways.

    I'm really trying hard to explain this without coming off like a jerk, but you're not making it easy when you make incorrect assumptions and then post "LOL" simply because you still don't understand what I wrote. If I'm not being clear, simply say that and I can try and explain it another way. No need to turn this into an argument. No one is attacking you here. I'm simply trying to explain how you would run one of these without using the current sensor and why it still has benefits without that function.
    Last edited by adamky1; 8th January 2016 at 12:37 AM.

  10. #10
    Navigator
    Join Date
    Feb 2015
    Posts
    9
    My mistake, by the pictures it looked like you had the pnp plugged into the regulator. You never show where it's soldered down. You're good to go then as long as the wire withstands the current. Sorry for assuming.

    At a glance I couldn't be sure if it was a 5v regulator or a 12v. I thought 12v since the rest of your system except the cc3d and the receiver can run on 12v. You could have supplied the power for the cc3d and the receiver from the pnp but that's just a hassle of wiring. The way you have it configured is probably easier.

    Does the timer work since you're not using the current sensor?
    Last edited by InocentRoadkill; 8th January 2016 at 08:40 AM.

Similar Threads

  1. QAV250 RTF
    By Tielur in forum GetFPV
    Replies: 1
    Last Post: 19th August 2015, 10:14 PM
  2. Tbs qav250
    By Thinktank in forum RC TECH
    Replies: 1
    Last Post: 15th August 2015, 07:55 PM
  3. FURY BOARD QAV250 TBS CORE OSD HARD TO SEE VOLTAGE
    By Rafael Torres in forum Team-Black Sheep
    Replies: 2
    Last Post: 7th November 2014, 08:20 PM
  4. Does anyone fly with a gps on their qav250?
    By Hollywood911 in forum LUMENIER
    Replies: 3
    Last Post: 31st August 2014, 12:50 AM
  5. QAV250!!!
    By supergimp in forum LUMENIER
    Replies: 19
    Last Post: 27th November 2013, 10:33 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •