[Fwd: Electronic Dynos]

[Mazda Ebrahimi]

Doug Robson wrote:
> 
> --
> |===============================================================|
> |                       When I die,                             |
> |         I want to go in my sleep, like my grandfather,        |
> |          not screaming like the passengers in his car.        |
> |---------------------------------------------------------------|
> |       Doug Robson                mailto:doug at cia.com.au       |
> |                               mailto:Doug.Robson at chase.com    |
> |    Sydney, Australia           http://www.cia.com.au/doug     |
> |---------------------------------------------------------------|
> |    Club Car Racing Register of NSW        |   Thank God       |
> |  1992/93 Under 2 litre State Champion     |      for          |
> | http://www.cia.com.au/doug/ccrrnsw.html   |   Gravity         |
> |===============================================================|
> 
>     ---------------------------------------------------------------
> 
> Subject: Electronic Dynos
> Date: Sun, 01 Dec 1996 20:07:04 +1000
> From: Doug Robson <doug at cia.com.au>
> To: diyefi <dif_efi at coulomb.eng.ohio-state.edu>
> 
> Ok so who want to discuss writing a program to convert the EMF against
> an engine dyno to Horspower and torque. is it easy or am i silly
> 
> regards


Hi Doug,

I'm not an electrical engineer, but I think this is what you're looking for:

	EI = T*2*Pi*n/60 or 
	T= (60*E*I)/(2*Pi*n)

	where:
	E is voltage	(in Volts)
	I is current	(in Amps)
	T is torque output (in Newton - Meters)
	n is speed of rotation	(in RPMs)
	Pi = 3.14159

An alternative method to measuring torque is using a load cell, which is comprised of 
two strain gages.  While the generator is supported by its bearings, the load cell is 
the only memberane that keeps it from spinning.  You can get a pretty accurate reading 
with a load cell within 0.5%.  This is the method most water brake dynos use.

Best Regards,
Mazda Ebrahimi