and the ability above make things understandable to everyone rather than get mega technical and make it NOT worth reading for some

 

Stu, I was of course aware you were actually congratulating Simon on how well written his answer was (the genuinely clever bit of his reply, his teaching skills) as opposed to the very basic physics he was talking about in the first place. And I was of course joking by making ohms law the subject of my reply when that wasnt the worthwhile content of Simon's reply. I added the bit about the appreciation of how Simon had written it to show that although I was joking about the physics of it being so simple it surprises me it wouldnt be obvious to all, I too was impressed at his writing skills in explaining it, as I didnt want him to think my reply was intended to take anything away from how good a job he had done of explaining it.

So you are totally correct it was indeed a case of conscience as I realised that my joke was potentially detrimental to the thread which wasnt my intention. It actually annoys me when people drag technical threads off course, so I didnt want to be guilty of it myself if my joke caused a row, with hindsight perhaps I should have deleted it altogether rather than just blunten the sharpness of the sarcam with a genuine comment about how well written Simon's reply was.

So genuine apologies to anyone my reply offends, was intended as humour but perhaps its not as funny as it seemed after an evening of sillyness and a few beers.
Further proof that keyboards should have breathalisers

 

agreed, that of course was the real genius in his reply

 

Simon,

Nice explanation. Thanks for taking the time to write it

 

TBH a typical Chip reply there, showing his true colours. Nice combo of patronising, snobbery and "look how great/clever I am"

Just the kind of attitude that is ruining this place IMO.

Need more posts like Simons. He took time to explain something complex with the aim being to teach us that don't know, rather than writing the post just to brag how clever he thinks he is

 

Typical Timrud reply just to bitch against me yet again. *yawn*

Your following me around bitching at me is just the kind of attitude that is ruining this place IMO, find something more useful to do.

My original post, although possibly wide of the mark, was intended purely to be humourous, yours is PURELY there to bitch and cause trouble and attempt to turn the thread into an argument yet again like you frequently do, so I think you need to look at your own actions if you want this forum to improve.


Agree, Simon's post is far better than posts like yours just bitching about other people all the time.

So hopefully this can get back on topic for more good replies
(The sort I frequently give myself, and you almost never do, as you seem to prefer just to bitch all the time)

 

ok stay on topic anymore bitching itll jut get dumped out of the thread

 

Thanks all to those who have shown appreciation


Chip,

I was trying to explain in my original post in terms that all can understand as not everyone undetsands ohms law and all the technobabble.

When I was 12, I was writting machine code software in hex code to make some disco lights flash and I knew nothing about ohms law.



You sound clued up my reply is probably within your knowledge already !

Technical reply....

Generally flyback voltage will slow down the response of the closing of the injector and this will be more noticable the larger the injector coil/size.

Serial resistors dont really present too much load to the injector in the flyback voltage stage so dont hinder the closing as the driver stage would have turned off sharply.
The only down side is that the output stage may have a zener diode or similar to clamp the high voltage emf pulse which will be higher on low impedance injectors and that in turn may present a significant offline load to slow down the close time/emf fall time.

I.E. The zener diode clamp voltage will be lower on a high impedance output stage causing a emf load on the higher voltage pulse of a low impedance injector as its voltage is higher.
This causes the injector to close slower although the serial resistor releive sthis slightly by reducing load slightly.



NON Technical reply....

When an injector turns off, it generates a high voltage pulse due to the generating effect of the coil and the magnet inside.
If this pulse has no where to go, the injector closes faster as the voltage isnt made to work.

Now as a high impedance injector driver has a diode clamp to protect it from voltage spikes generated by the injector, this clamp is sized at a voltage that is LOWER than that a low impedance injector requires.


So for HIGH IMPEDANCE INJECTOR, when it turns off, it may generate a 50 volt pulse at closing. This normally isnt enough to trigger the clamp as it will be set about 70-80 volts, the result, the pulse has no work to do and the injector closes as fast as it can do

WHen driving low impedance injectors using resistance form a high impedance ecu driver.....

LOW IMPEDANCE INJECTOR will generate a higher pulse voltage of around 90-120 volts which will trigger the clamp set at a much lower voltage causing a current flow which in turn slows down the rate of closing.


Hope that helps everyone to understand.





Peevee,

ECU's and all car stuff is fuck all compared to the laser systems I have built for the club mate.
Come on over some time and let me give you some free eye surgery ...

 

intresting as always simon!

 

Using resistors does 'slowdown' the injector as there is a voltage drop / power dissipation across the resistor - power/voltage that doesn't get to the injector. All the 'injector driver' boxes will be will be input load resistors connected to relatively high power transistors of some spec, which would then drive the injectors.

Chris

 

Good read, Nice one Simon.