View Full Version : Introducing the Digital Power Recorder (DPR), In-Flight Data Recorder.

08-24-2005, 01:27 PM
BNB Products is very excited to inform you about the new Digital Power Recorder (DPR). The DPR is a very small and lightweight device (about the size of two quarters) that allows you to track and record all the power and temperature readings of your R/C craft during actual use! After the data has been recorded, you can upload the data to your computer and graph all the data with the powerful DPR-Graph software included with eack package. We currently have two models available: the DPR-50 (50 Amp max) and the DPR-100 (100 Amp max).

You can find out more, and order the DPR at www.bnbproducts.com (http://www.bnbproducts.com) . You can also download the DPR manual and the graphing software with two sample missions. We also now have several dealers offering the DPR, so please review our "Dealers" page on our site.

Some of the DPR feature include:
Very small: 1.2 inches x 1.6 inches
Very lightweight: Approximately 0.9 ounces (25 grams)
Accepts wide range of Voltage inputs: 7 to 30 Volts
Digitally records up to 9+ hours of mission data

Records and Graphs:
Current draw up to 50 Amps
(up to 100 Amps with the DPR-100)
Battery Voltage from 7 to 30 Volts
Power Output up to 1500 watts
(up to 3000 watts with the DPR-100)
Amount of charge used
Battery efficiency (Voltage drop under load)
Elapsed time of each mission
Temperatures of two independant temperature probes
(Dual temperature probes are sold seperately)

Data sampling rate
Recording trigger
Channels to record
Computer graph displays with the DPR-Graph software
Recording resolution

Very easy to set up and use!

Each DPR package includes:
Digital Power Recorder (DPR-50 or DPR-100)
3-foot USB-A to mini-B interface cable
CD-ROM with powerful graphing software, USB driver support, and soft version of manual
Hard copy of manual

System requirements:
PC with one of the following operating systems:
Windows 2000 or Windows XP
CD-ROM drive (or access to the internet)
Available USB port
2 megabytes of hard drive space

Our goal is to provide the best broducts and service possible. Please contact us with any questions, comments, or concerns...WE WANT TO KNOW!

Bret Newman
www.bnbproducts.com (http://www.bnbproducts.com)

10-14-2005, 12:03 PM
Hi Bret,

In the manual it is reported that the DPR is capable to work fine with voltage below 7V if it is power over the USB cable. That is fine for bench tests ... but not for live tests.

My idea it is: can I make a connector that take the 5Volt from the BEC and send it over a custom USB cable to the DPR ?



10-17-2005, 09:02 AM
One more observation over my DPR 100:

I did notice that in case the current is changing direction (some ESC do have some charge back functions when brake is apply) ... then the DRP unit start to missbehave:

The DRR unit is capable to report only positive number, in case of negative value, this will be report till like a 0, and the scale get messed up, since the real 0 AMP value will be reported like the ABS(max reverse current).

Is there any software or firmware update that fix the problem ?


10-28-2005, 11:57 AM

10-29-2005, 01:34 AM
Sorry for the delay. Our Tech should have contacted you by now. If you have any further concerns, please let me know.


10-31-2005, 10:51 AM
I guess it will be good to share the response from BNP:
for the USB power, the newest version of the DPR firmware supports this idea.

Here is what you should know

1. Must have DPR firmware ver 1.03 or newer (click "About" in the DPR-Graph menu to verify your version)
2. The voltage you supply to the DPR from the USB must be very close to 5.0 volts
3. The voltage also must be very stable
4. The 5.0 volts should be applied to the 'red' USB wire.
5. Make sure the gnd (0 volts) that your suppling is at the same potential as the shield of the USB connector on the DPR. If you have no voltage potential, then apply gnd (0 volts) to the USB 'black' wire.
6. Short the USB 'data' wires 'green' and 'yellow' to gnd (0 volts)
7. Keep in mind, the USB (power source) cable should be as short as possible.

for the reverse current issue, the DPR was not designed to handle dynamic current polarity changes. The next firmware version will deal with this rare issue.

Please note that this not the standard usage of the BNP DPR.


PS: Actually the reverse current is not a rare issue ... did verified on cars and airplane, when brake is active, using a BL ESC

Heidelberg Germany Flyer
11-01-2005, 06:43 PM
Hi Bret!

Just purchased and received a DPR-50. Love it so far. I have just a few questions, this one bothers me a little...

Is there any occasion that the DPR will shut down in flight and not allow sufficient current to the plane? I know that when it gets under 7 volts that the DPR will shut down without changing the planes current, but will the DPR always allow current to the plane, regardless of overheating, excessive vibrations, etc.? I could understand if the connectors disconnect, but would like some confirmation that the DPR will never cause a power down in the plane.

The second question deals with some of my fellow members asking me to give a read-out of their planes with the DPR. I made some short converter connections that allow other planes to be connected to my DPR. They are about 2 inches long and plug into each end of the DPR. Will these converter connections cause incorrect readings?

Thank you taking time to respond to my questions. By the way, could you add a print option in the next software upgrade?



11-01-2005, 10:58 PM

The only way the plane would lose current is if the battery wires of the DPR are somehow severed from the DPR circuit board.

All wires above 0 deg K have resistance. Therefore current flowing through such wire will waste some power. If your home-made converter uses high current wire with good solder joints, the power loss caused by two inches should not be noticable.

www.bnbproducts.com (http://www.bnbproducts.com)

11-08-2005, 06:05 PM
Hi Bret,
I am looking for a system like the DPR-50 to record one parameter that I don't see as listed. I need to compare the time taken when accelerating a motor from a given RPM to a second step RPM, say what ever hover RPM and max upline RPM might be. Does your system have the ability to sense and record motor RPM and compare it against time? If it does can it also overlay one motor or prop run on to a second dataset motor or prop run in the same graph for dirrect comparison display?


11-08-2005, 06:21 PM
At this time, we do not offer a RPM sensor for the DPR. This is something we are considering though.

www.bnbproducts.com (http://www.bnbproducts.com)

Heidelberg Germany Flyer
11-09-2005, 07:24 PM
Hi Bret!

Have been using my DPR without any problems. Don't know how I've done without it in the past. It's great that I can transfer the data on my computer.

I bought the 2 temp probes and the single LED and temp probe options Any suggestions, cautions on using them? What temperatures should I be looking for on the batteries, motor, and controller? I'm running the Astro 20 system with 1500 mAh 3 cell batteries.

Thanks for your assistance!