Water brake Dyno conversion to load cell

[Markems]

I have just bought an old Froude Hofmann DPX2 water brake dyno. I am wanting to convert it to a load cell and run some software on my computer instead of all the manual calculations. I have found various free software versions on the net most of them want you to buy there interfaces (expensive £1000 or more). Dose anyone know of sensible priced interfaces or a way of getting it all to work. Below is a link to one of the software

http://www.sportdevices.com/download/index.htm

 

[GregLocock]

If you know the roundy-roundy-ness, and the hardy-pushiness, then all the rest is frippery.

P=T*(rpm/60)*2*pi





Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Markems]

HI
Thanks. But I can do the calculations, I would just like to have some software do it for me and maybe produce a graph (but not essential).
Mark

 

[IceStationZebra]

It depends on what your requirements are. If you want the near-instant graphing of power & torque vs. RPM you will be pretty much stuck with these types of systems unless you can get someone to code some custom software.

If you are willing to create the graph after the dyno run is done you could use almost any two channel data logger, 2 signal conditioners with a analog-to-digital card in your computer, or even a signal conditioner/analog-to-digital combo that output data to the USB port. Then you can graph the data with the included software or a spreadsheet program like Excel. You might also be able to get a realtime readout if the software supports computed channels. I can't recommend any particular brands/models as you are not in the USA, but you should be able to find something that comes with a simple software package.

Have fun! ISZ

 

[GregLocock]

If you've got a parallel port on your PC, and your ADC plugs into that, then a quickbasic program is dead easy to write, in fact I've got one somewhere.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[BCjohnny]

Greg,

I too would be interested in anthing you have as I'll be doing much the same thing with a water brake, mine an uprated Heenan Froude G4.

Regards, John.

"It's not always a case of learning more, but often of forgetting less"

 

[EdDanzer]

IOtech’s data collection system will do what you need.

http://www.iotech.com/

Their software is not too difficult to set up for a specific transducer input.

 

[GregLocock]

As a more up to date alternative you might like to download xlxtrfun which allows you to read and write to ports from inside excel, thereby giving you easy graphs and so on.

Here's a simple basic program that can easily be modified for realtime monitoring of the parallel port. Obviously your particular ADC won't use the same pins for the same functions.

CLS

base0 = &H378

PRINT "Power on and deselect adc"

OUT base0, &HA0

DIM v(12)




start:
INPUT "Enter -1 to finish"; jjj
IF jjj = -1 THEN GOTO finish

FOR n = 0 TO 11
v = 0
cycle = 0

cyclestart:
cycle = cycle + 1
OUT base0, &H60 ' text says 80

v = v OR (INP(base0 + 1) AND &H10) * &H8

FOR clk = 1 TO 4
address = &H80 + &H40 * (n AND 2 ^ (4 - clk)) / 2 ^ (4 - clk)
v = v OR (INP(base0 + 1) AND &H10) * (2 ^ (8 - clk)) / &H10
OUT base0, address
OUT base0, address OR &H2
OUT base0, address AND &HFD
NEXT clk

FOR clk = 5 TO 8

v = v OR (INP(base0 + 1) AND &H10) * (2 ^ (8 - clk)) / &H10
OUT base0, &H82
OUT base0, &H80

NEXT clk

OUT base0, &HA0
DO WHILE test = 0
test = INP(base0 + 1) AND &H40
LOOP

IF cycle = 1 THEN
v = 0
GOTO cyclestart
ELSEIF cycle = 2 THEN
v = v
END IF





NEXT n

IF v(11) > 130 OR v(11) < 126 THEN PRINT "adc error"

FOR n = 0 TO 11
IF n < 10 THEN v = CINT(v * 100 / 51.2) / 100
IF n = 10 THEN v = v / 10

PRINT n; ": "; v; " ";

NEXT n
PRINT

GOTO start

finish: PRINT "power down .."
BEEP
OUT base0, &H0
STOP
END



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[GT6Steve]

MArkems,
I hope I'm not out of line here but if you do manage your upgrade I'd be interested in talking to you about your waterbrake.
Regards, Steve

 

[GT6Steve]

Forgive that ignorance, I just read what you actually wrote as opposed to what I actually read. If ya know what I mean. Sorry. Steve

 

[Markems]

Hi
Thanks. I am looking into A/D cards ant the software that comes with them. Will let you know how i get on.
Mark

 

[Markems]

I have been looking at A/D cards and devices and have found one at a low cost £89. Even the software that comes with it is Muppet proof (must be if I can understand it). Have been told it's fast enough a will do the job. Will someone please give a second opinion.
Mark

A/D converter

http://www.audon.co.uk/labjack.html

Software

http://www.audon.co.uk/daqfactory.html

 

[IceStationZebra]

It looks like it will do the job. You should be able to use the analog out for your load cell. And the digital input should work as long as you adhere to the voltage requirements - it will look something like must drop below 50mv and go above 200mv to trigger a count. ISZ

 

[bsfc9]

check out this company. DEPAC.

http://www.depac.com/index.htm