Author Topic: Rosetta, power consumption  (Read 559 times)

rogellis

  • Full Member
  • ***
  • Posts: 121
  • Total likes: 1
  • welcome to the PilotAware forum
    • View Profile
Rosetta, power consumption
« on: April 16, 2019, 03:48:38 pm »

Just laying out the (all electric) instruments for our new super-lightweight** Me7 glider, which goes on sale this summer.  And was thinking of installing a PAW unit as standard in each one. 

Q.
Could anyone give me the standard (average) power consumption of the new Rosetta, as I hear it has reduced from the original 5w.   

Roger

** Single seat,  carbon fiber airframe,  32:1 glide, total airframe weight 105kg,  MTOW 240 kg.

.

Admin

Re: Rosetta, power consumption
« Reply #1 on: April 16, 2019, 04:57:52 pm »
Hi Roger

Recommendation is still for a 2.1Amp supply, we recommend Anker, we have found them to be the most reliable

Thx
Lee

Vic

Re: Rosetta, power consumption
« Reply #2 on: April 16, 2019, 07:43:37 pm »
Certainly need the capable power supply as stated by Lee to cope with surges etc.

Mine (with a Pi3) after boot and running normally has an average current drain of 600mA as measured by one of those USB volt/current devices

Vic

Ian Melville

Re: Rosetta, power consumption
« Reply #3 on: April 16, 2019, 07:51:47 pm »
Just measured mine at 590 mah, which is in the same ballpark as Vic's report. Just under 3w Average.

Peak wattage is quite a bit higher hence the need for a good supply.

rogellis

  • Full Member
  • ***
  • Posts: 121
  • Total likes: 1
  • welcome to the PilotAware forum
    • View Profile
Re: Rosetta, power consumption
« Reply #4 on: April 20, 2019, 07:17:33 am »
Just measured mine at 590 mah, which is in the same ballpark as Vic's report. Just under 3w Average.

Peak wattage is quite a bit higher hence the need for a good supply.


Yes, I thought average would be well below peak (peak being up to 10w).
And 3w is much better than the 5w on the old PAWs.
Makes it much easier for battery usage.

Cheers,
R

JCurtis

Re: Rosetta, power consumption
« Reply #5 on: April 20, 2019, 10:55:10 am »
If I could get hold of a Rosetta for a few hours i can easily hook it up to get a definitive power profile. I did the previous generation.

The plug in usb power meters are not very accurate. However the kit in my workshop is very accurate and calibrated.
Designer and maker of charge4.harkwood.co.uk, smart universal USB chargers designed for aviation.  USB power without the RF interference. Approved for EASA installs under CS-STAN too.

SGS66

Re: Rosetta, power consumption
« Reply #6 on: April 21, 2019, 04:50:14 pm »
Hi Roger,

I bought a Rosetta about mid Feb this year and use it with SkyDemon. I already had a Ravpower 10,000mah power bank so decided to use this to power the Rosetta. Since then the Ravpower bank has worked without problem and at end of March I decided to see how long it would work (powering the Rosetta) from full before going flat.

So 29 Mar out flying for short flights but leaving the Rosetta plugged-in even when not flying it was on for 5.5 hours, from arriving to leaving the aircraft for the day.
A few days later an 'on' time of 1.5hours was added. Again a few days later the Ravpower was used to keep the Rosetta running for a trip to France and back 3hrs.
Finally the SkyDemon lost location data on another day (18 April) after a further hour of taxing and flying which I figured was a power problem and though I managed to start SkyDemon navigating for the landing I concluded that the power pack had not enough power to continue faultlessly.

Whilst disconnected the Ravpower bank was left in my hangered aircraft. When I was using my Ipad (a subset of the hours) the time was split between having my Ipad Mini 4 hardwired to my intercom for SD speech and latterly using a bluetooth dongle plugged into the intercom. Generally I would get to the aircraft, plug in the Rosetta and then do the walk round etc, listen to the ATIS and call for taxi so the Ipad was not connected wirelessly until I was about to taxi. The overall hours on for the Rosetta were determined by analysing the trk data using 'Aircrew'

So there you have it 10,000 mah = 11 hours powering the Rosetta. Of course nobody wants to run with the 'tank' empty
so 10 hrs would be more conservative for a piston engine bus driver.

I have now bought an identical Ravpower bank to keep as a fully powered spare.

Good luck with your project -  it sounds exciting.

rogellis

  • Full Member
  • ***
  • Posts: 121
  • Total likes: 1
  • welcome to the PilotAware forum
    • View Profile
Re: Rosetta, power consumption
« Reply #7 on: May 04, 2019, 12:44:44 pm »
Quote
I already had a Ravpower 10,000mah power bank so decided to use this to power the Rosetta.

Thanks SGS.

What voltage is your powerbank?  Is that a 5v pack, for an iPhone?

My battery is 10,000 mah, but at 12v  -  so twice the power....


Presumes Calcs:
You have 10 ah x 5.5v  =  55 Wh energy.
For eleven hours = average 5w consumption.

But if you powerbank is only giving 8 ah in reality, then...
You have 8 ah x 5.5v  =  44 Wh energy.
For eleven hours = average 4w consumption.


Thanks,
RE


« Last Edit: May 04, 2019, 01:03:10 pm by rogellis »

SGS66

Re: Rosetta, power consumption
« Reply #8 on: May 04, 2019, 07:19:19 pm »
Roger,

As you figured I powered the PAW from a 5v source. The bank has two USB out ports claiming a 5v/3.4A max
but of course I was only using one port for my trial to see how long it would power the PAW. I never checked the precise voltage.

Phil

 

Paul_Sengupta

Re: Rosetta, power consumption
« Reply #9 on: May 09, 2019, 06:48:19 pm »
Power banks tend to specify the amp-hour rating of the batteries within. With these being lithium, the nominal voltage at which they're quoted will be 3.7V. It won't be the capacity at 5V, annoyingly!

rogellis

  • Full Member
  • ***
  • Posts: 121
  • Total likes: 1
  • welcome to the PilotAware forum
    • View Profile
Re: Rosetta, power consumption
« Reply #10 on: May 14, 2019, 03:49:23 pm »
Ok, just got my new Rosetta.

Power consumption from my 12v battery varies from 0.24A to 0.28A, depending upon how hard it is working.

That is 2.9 to 3.4 W.    A definite improvement upon the old version.

Thanks all....
RE

rogellis

  • Full Member
  • ***
  • Posts: 121
  • Total likes: 1
  • welcome to the PilotAware forum
    • View Profile
Re: Rosetta, power consumption
« Reply #11 on: May 14, 2019, 04:04:58 pm »
Regards power supply, I bought the following from Ebay......

12V to 5V 3A 15W USB DC-DC Buck Converter Charger Step Down Module Power Supply

This is a very lightweight in-line unit, and seems to give the 3 Amp it claims. Just chop off the USB connector, and go. 

RE