FrSky Redundancy Bus - PowerBox - RC Groups
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Jan 22, 2016, 05:57 AM
FJH
FJH
Registered User
Discussion

FrSky Redundancy Bus - PowerBox


FrSky has the announced PowerBox on its web site now

http://www.frsky-rc.com/product/pro.php?pro_id=155


FEATURES

● Overload protection on each channel.

● Possibility to connect up to 2 receivers with serial interface(SBUS).

● MPX battery input connector(s):2 battery inputs.

● 50Hz mode if servo outputs (10ms period) of Equal to the input of SBUS cycle.

● Support S.Port Telemetry (Voltage,current,capacity measurement,overload indication ...) sensors.

● Easy settings of switching mode of servo outputs.

● Firmware updates by user.

● Suitable for use with high voltage (HV) servos.

● Compact size for easy installation.
Last edited by FJH; Jan 22, 2016 at 09:51 AM.
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Jan 22, 2016, 09:02 AM
Taranis Tyro...
MattyB's Avatar
I have been waiting for a product like this from FrSky, though our experiments with the XPS X10+ have been successful too. Instructions could do with some work though, they are a bit basic.. (EDIT - Looks like manual has been pulled for a much needed rewrite)

PS - Can I suggest you change the title of this thread to FrSky Redundancy Bus - yes PowerBox was the original publicied name, but for obvious reasons that has now been dropped. Besides, it does a lot more than provide resilient power.
Last edited by MattyB; Jan 27, 2016 at 07:40 PM.
Jan 22, 2016, 10:03 AM
FJH
FJH
Registered User
Hi MattyB,

What do you think about their design, which as I understand will drain both connected batteries in parallel. Wouldn't it be better, under the aspect of safety, to have one distinct main battery and a second standby backup battery. In case that main battery voltage drops below adjustable level it then should switch to second backup battery and pass an alarm to the Tx, or Tx should alternatively receive some indication from the powerboard which battery is active? That would allow to set some alarm in the Tx. I would at least prefer such a design.
Jan 22, 2016, 10:35 AM
Taranis Tyro...
MattyB's Avatar
I can see your point, but don't think it matters much. I suspect they have steered away from embedding any active SPORT telemetry functionality into this device so that a) it works with any make of RC, and b) someone wanting a setup such as yours needs to buy a couple of battery voltage sensors...!

EDIT - Just looked again at the instructions, and they are very unclear... I cannot work out if the extract below means the Bus will output all of the listed data direct to the RX, or whether additional sensors are required? Very confusing. If all it needed was a wire to the RX you'd have immediate information on a battery going down or RX failure at the TX; that would be excellent.
Last edited by MattyB; Jan 22, 2016 at 10:47 AM.
Jan 22, 2016, 10:46 AM
Taranis Tyro...
MattyB's Avatar
Extract from the instructions...
Jan 22, 2016, 10:48 AM
FJH
FJH
Registered User
The board itself has a smart port connector, so what should that be for? Ahhh, I see from your post, seems I lost that page in the board description. So we have some telemetry data from the board.

Draining the batteries in parallel (why? for more current? I don't need) or one by one with the dedicated backup battery to be drained as second is a matter of design philosphy.
Last edited by FJH; Jan 22, 2016 at 10:56 AM.
Jan 22, 2016, 11:01 AM
Taranis Tyro...
MattyB's Avatar
If (and it is an if at this point) the board can push out the battery telemetry for both packs then draining both in parallel makes no difference - you will still know if one fails, as your TX will chirp when the batt voltage for a given pack goes below a certain value. The only disadvantage I can see of this method is that you will always have to charge both packs every time, whereas with your method it would be safe to leave the backup between sessions without a charge (provided they weren't months apart) if it had not been used.
Jan 22, 2016, 11:12 AM
FJH
FJH
Registered User
The difference is that parallel drainage brings down both batteries, so at alarm time both will be voltage low, while otherwise concept switches to full load backup battery.
Jan 22, 2016, 11:33 AM
Froggy RC Pilot
LapinFou's Avatar
According the user manual, the powerbox included a current sensor (and also consumed capacity) + a voltage monitor for each battery + an overcharge indicator for each servo output + the number of transmitted channel (and signal period) for each RX inputs.
A S.Port wire must be added between the powerbox and the RX used for the telemetry.

So you will be able to detect if one of the battery is failing.
Jan 22, 2016, 11:41 AM
FJH
FJH
Registered User
All positive, no question. However it doesn't change the matter of both batteries being drained simultaneously. This kind of design provides just an increased battery capacity.
Jan 23, 2016, 08:03 AM
Registered User
The batteries aren't in parallel physically connected, just logical. This can be very easy done using Schottky diodes. Each of them became the main battery, discharge some mV, then the other takes over and so on. Any moment they are equally discharged.

What I dislike is the glaring, no excuse, copy of the Jeti power box case design... is without any shame, and will amplify the claims that Horus has Jeti inspiration too.
The most obvious is the usage of MPX plugs, which are mainly preferred in the German modellbau, where Jeti belongs, without any history in Frsky preferences, or any other Asian brands, to justify this choice. We should see up there the yellow of XT plugs, or preferably just soldering pads, for everyone taste.
Jan 23, 2016, 09:06 AM
Registered User
Quote:
Originally Posted by renatoa
What I dislike is the glaring, no excuse, copy of the Jeti power box case design... is without any shame, and will amplify the claims that Horus has Jeti inspiration too.
It is interesting to read exaclty the same paragraphs in both manuals:
Jan 23, 2016, 09:08 AM
Taranis Tyro...
MattyB's Avatar
Quote:
Originally Posted by renatoa
...What I dislike is the glaring, no excuse, copy of the Jeti power box case design... is without any shame, and will amplify the claims that Horus has Jeti inspiration too.
The most obvious is the usage of MPX plugs, which are mainly preferred in the German modellbau, where Jeti belongs, without any history in Frsky preferences, or any other Asian brands, to justify this choice. We should see up there the yellow of XT plugs, or preferably just soldering pads, for everyone taste.
Agree 100%; there was just no need to copy the physicals in this way. As to the Mpx greens, I doubt most of their target market have ever even heard of them, let alone soldered one up. Baffling.
Jan 23, 2016, 12:13 PM
espritmodel.com
Quote:
Originally Posted by Ciusna
It is interesting to read exaclty the same paragraphs in both manuals:
Thanks, we will keep those jewels. Jeti is proud to have such a close following.
But you are right the Multiplex MPX connectors are puzzling.

Zb/Esprit
Jan 23, 2016, 12:25 PM
Registered User
The nice thing about the MPX plugs is that they are fairly easy to pull apart, the XT and ECs take a bit more force, so you'd have to have the unit securely anchored.


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