Thoughts on crank angle sensing

[Andrew Dalgleish]

On Tuesday, 27 February 1996 23:27, owner-diy_efi-outgoing wrote:
[snip]
> How about using a counter reset by every tooth. Then read the number   
and you
> have a count proportional to velocity.
>
> >
> >As for instantaneous acceleration,
>
> Subtract this reading from the last and get acceleration
>
> Phase lock loops are difficult to make reliable and keeping it digital   
keeps
> it simple.
>
> Peter Wales
> President Superchips Inc
> Chairman Superchips Ltd        "Timing is everything"
> Superchips home page with all the answers http://www.superchips.com
>
>

What you are suggesting is a simple form of digital PLL (or is it   
frequency locked?)

I used a latch->rom->latch to lock on to the data stream for a floppy   
disk interface about 10 years ago.

The advantage of the all digital approach is you can do (simple)   
prediction as to when the next pulse will appear.
(ie what comes after 5,4,3,...)

You still have design problems, just different ones :-(
Regards,
Andrew Dalgleish
Axon Research, Pty Ltd
6 Wallace Ave,
Toorak, VIC
3142
AUSTRALIA
Tel +61-3-9826-5538
Fax +61-3-9824-0083