Talk:Dynamometer

Pandynanometer

But what was Gustave-Adolphe Hirn's pandynanometer? It does exist [1] Cutler 11:08, 7 March 2006 (UTC)[reply]

Eddy current?

What is an eddy current dynamometer? --Gbleem 04:22, 1 June 2006 (UTC)[reply]

See answer below by =Motorhead. I have added eddy current or electromagnetic brake to the article under heading: Types of absorption units. --C J Cowie 16:27, 1 June 2006 (UTC)[reply]

Why is it called brake horsepower?

Is there non-brake horsepower? --Gbleem 04:25, 1 June 2006 (UTC)[reply]

Brake horsepower refers to horsepower measured by braking the engine which is what dynomometers do as opposed to all the other possible horsepower designations such as friction horsepower, indicated horsepower, pumping horsepower etc.

An eddy current dynomometer is a type of electric dyno or "brake" which used magnetic/electrical currents induced in a spinning disk to provide the resistance. Similar in principal to some old mechanical speedometers.--=Motorhead 10:02, 1 June 2006 (UTC)[reply]

I think that brake horsepower generally refers to actual operating horsepower measured under specific operating conditions as opposed to rated horsepower or nominal horsepower. The term is often used to mean the actual horsepower that must be applied to the shaft of a pump to produce a specific flow at a specific head. Pumping horsepower may mean the power represented by the actual flow of water which would be the brake horsepower input at the pump shaft minus the energy losses dissipated as heat in the pump. --C J Cowie 16:27, 1 June 2006 (UTC)[reply]

In this case, by "pumping" I was referring to pumping horsepower as in "pumping mep", the horsepower required to pump gasses into and out of the engine, not to the workings of the brake itself.

Rated and nominal horsepower are artificial constructs by factories, insurance companies, governments etc. with a special interest and agenda. Totally non scientific and not considered at all in my comment. If you didn't measure the power on a dyno or "brake", you simply do not and cannot know the power output. All the other alternate terms I used are real measurable factors which happen to share the word "horsepower".

It would be good to point out in the article the differences between all those you mentioned though. So readers wont be fooled by some advertisers wet dream.--=Motorhead 00:39, 2 June 2006 (UTC)[reply]

I am not inclined to address the use or misuse of horsepower ratings in this article. Every product that contains an engine or motor is likely involved with some version of this problem. See: Talk:Electric motor#does horsepower really equal 750 watts?. The horsepower article also addresses some aspects of this problem. --C J Cowie 17:37, 2 June 2006 (UTC)[reply]

Inventor of the Dynamometer

I work at an engineering company and i am under the impression that William Froude invented the dynamometer. This article indicates it was Charles Babbage. Charles' page indicates he did a lot of work with computers, which were called 'engines' but nothing to do with dyno's. Could you confirm your source for this? :o)

Gaspard de Prony invented the de Prony brake in 1821. The de Prony brake (or Prony brake) has been considered to be one of the earliest dynamometers, but I don't know if it is claimed to be the first. C J Cowie 14:15, 23 June 2006 (UTC)[reply]

Since William Froude was born in 1810, the invention of the Prony brake must have predated whatever type of dynamometer he invented.C J Cowie 14:27, 23 June 2006 (UTC)[reply]

According to http://www.froudehofmann.com/about_1.htm, William Froude invented the hydraulic dynamometer in 1877 and Heenan & Froude was established and produced the first commercial dynamometers in 1881. C J Cowie 14:37, 23 June 2006 (UTC)[reply]

I have found a couple of references that indicate that, in about 1838, Charles Babbage built "what must have been the first example of a dynamometer car" for testing railroad engines. The information about Babbage needs to be moved to the dynamometer car article and the information about de Prony and Froude put in this article. C J Cowie 22:49, 23 June 2006 (UTC)[reply]