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Old 5th May 2011, 23:24   #106
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Default Re: Camless and electronic timing : The future?

Well, you need to learn a lot of physics and electronics, despite you years of experience in ABS/airbag/... software development before you talk to people who are designers who deal with physics to earn their bread.

BUT before that you need to hold a civil conversation.


PS: thanks for runing my experience on team-bhp and curing my addiction for the forums.


Quote:
Originally Posted by DerAlte View Post
<Sigh> You should try and understand the Kabir doha:
Pothi padh padh jag mua, pandit bhaya na koye,
Dhai akhar prem ka, padhe so pandit hoye
'Prem' here represents worldly experience, without which one does not get wisdom - and that does not come from books. Get your nose out of books and go out and smell the coffee, buddy.

1. The diode you are pooh-poohing is called a quenching diode, and connecting that in reverse across the relay/contactor coil or the switching contact is a standard practice (will always be) in electrical panels. It safely prevents the back-EMF from producing an arc across the switching contact. Without this there will be ultimately a. insulator breakdown in the coil causing it to short and fail and b. erosion in the contact material of the switching contact

2. You seem to have found a sure-fire method of 'accelerating charge' and producing current without any voltage (sure, one can sit and move a soft iron core in and out of the solenoid coil perpetually to get that current without needing voltage).
Otherwise, wherever the brushes jump up and down on the surface imperfections of the copper rings, they cause first a disruption of the voltage being applied on the field coil (first dV/dt) causing back-EMF in the field coil (dI/dt caused, resulting in second dV/dt, -ive) which leads causes arcing (micro-arcing) which causes more dV/dt and dI/dt, all of which produce nasty RF noise. And one has the whole field coil as an antenna, though RF comes out of only the ventilation holes. Capisce? Now, could you please try to explain this to me with Maxwell's and other equations?

What perhaps you are not understanding is that when we are practically dealing with product engineering (whether in forward or in reverse), we are never trying to solve fundamental equations. At that time, we are only applying technology, which systematically creates building blocks by applying appropriate science, which has created and solved all the fundamental equations. If you are reverse-traversing the science->technology->engineering, we need to get the right reference points right otherwise we land up in an unintended state. I am sure you will not agree with this.

What would you call a signal whose magnitude continuously varies but aperiodically (cannot resolve fundamental sinusoid components / too many fundamental sinusoid components, like in white noise; possibly with DC bias)? DC? AC?

Last edited by vina : 5th May 2011 at 23:25.
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Old 27th February 2014, 12:59   #107
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Default The new age of Camless engines

I happened to come across an article on 'Camless Engines'. A revolutionary idea nonetheless, but is it pragmatic. If achieved, it can open up an entire new era of IC engines, with infinite possibilities and countless configurations.
Please have a look at the article(s).

http://jalopnik.com/what-its-like-to...ine-1529865968
http://www.core77.com/blog/transport...ient_24576.asp

Last edited by Roomy : 27th February 2014 at 13:01.
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Old 27th February 2014, 14:06   #108
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Default Re: The new age of Camless engines

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Originally Posted by Roomy View Post
I happened to come across an article on 'Camless Engines'. A revolutionary idea nonetheless, but is it pragmatic. If achieved, it can open up an entire new era of IC engines, with infinite possibilities and countless configurations.
Please have a look at the article(s).

http://jalopnik.com/what-its-like-to...ine-1529865968
http://www.core77.com/blog/transport...ient_24576.asp
In a SOHC configuration, we have 2 rocker arms, one for the inlet and exhaust valve operated by cam shaft while in DOHC, we have 2 cam shafts for each of the valves thereby eliminating the rocker arm. With solenoid valve actuation it should be possible to eliminate cam shafts all together. Opening and closing of the valves will be precisely controlled.

Last edited by suresh_gs : 27th February 2014 at 14:09.
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Old 27th February 2014, 20:58   #109
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Default Re: The new age of Camless engines

Almost everyone has thought of it, some have tried it, none have so far managed to make a system reliable enough (and not even talking of cost) to put on a race, or sold to public road vehicle.

Checkout Fiats multiair (which is a different system, but with similar goals.)

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Old 28th February 2014, 00:04   #110
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Default Re: The new age of Camless engines

Such engines are already in commercial service in marine industry. It is used as main propulsion engines for ocean going ships.
Check out MAN B&W and WARTSILA SULZER camless engines.
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Old 28th February 2014, 10:13   #111
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Default Re: The new age of Camless engines

hi !

Cam less engines have been in the marine industry for sometime now.

i've worked on one in my last ship which was manufactured by MAN B&W.
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Old 28th February 2014, 14:18   #112
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Default Re: The new age of Camless engines

I understand a similar concept is being used in marine engines for sometime, but using the same in a car engine has never been successful enough.
Also, what i found really interesting is
Quote:
What else is amazing is that it can run in a number of modes. They can run it as a two stroke at lower revs, which effectively improves power delivery to make 3,000 RPM feel like 6,000. It can run the Miller Cycle, which sounds complicated but improves both power and efficiency. Christian said it can run diesel or gas.
Quote:
In order to get that sort of variability that Freevalve has, you'd have to totally switch cams. Freevalve can also shut down one cylinder, two cylinders, three cylinders, etc.
An engine that can be converted to a two stroke, fed multiple fuels, albeit not simultaneously, on the fly conversion to lower no of cylinders; this is something which would truly be multi-purpose. Power on demand, without the FE taking a major hit. This is where the IC, in my opinion, should be heading to in the wake of alternative energy powered vehicles hitting the market.
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