Knock sensors (SAAB)

[Peter Gargano]

Actually the Trionic system is a capacitive Discharge (CDI)
system so that it's actually an expanding AND collapsing magnetic
field (sorry to be so technical!).

Another interesting thing is that the primary coil is just 10 turns.
They used flat wire to give a low resistance AND so thay could cool
the coils more easily. As it's a CDI system, the capacitor is charged
to perhaps 400 Volts and this also helps to generate the claimed
40,000 Volts (that's just a 1:100 ratio, not 1:3000 for a 12-14 Volt 
conventional ignition system)

A70Duster at aol.com wrote:
> 
> Peter Gargano  wrote:
> 
> << including a cutaway of their Trionic coil - seems to have a ferrite
>  core and turns ratio of about 1:5, but they claim "40,000 at the moment
>  of ignition" - explain that! >>
> 
> The voltage from an inductor is
> 
>       v(t) = L di/dt
> 
> Also collapsing magnetic fields.  Plus 40 kV is not new to electronic
> ignition systems.

-- 
Peter Gargano