Hall sender trigger angle?

[Floddy]

Hi,

Does anyone know at how many degrees BTDC the hall sender triggers?

Thanks,
Floddy

[S2central.net]

I have some scope traces that might be able to determine that by some judicious reverse engineering... I know for fact that it creates a window around the crank reference pulse which is 62 BTDC.

Let me dig up the scope traces at idle - should expose the open and close times for the hall window.

[Floddy]

That would be great, thanks!

[S2central.net]

At idle (~800rpm) the hall effect window opens 4ms before the crank pulse... Drat I need to dig up some other calculator I had to convert that into degrees.

[S2central.net]

OK - from 1st principles then

Assume crank rpm = 800 gives us 13.33333 revs per second
or 75ms per crank revolution

Therefore 4ms is 19.2 degrees

After the cranks pulse there is another ~4ms before the hall window closes

Sound right ?

[Floddy]

I was doing some math before reading the last post and came to the same conclusion.

800rpm / 60 = about 13.33 rotations per second
13.33 / 1000 = 0.01333 rotations per millisecond
0.01333 * 4 = 0,05332 rotations per four milliseconds
360 * 0,05332 = about 19.2 degrees

That would mean that the window opens at roughly 81 degrees BTDC, and closes at about 43 degrees BTDC, right?

Thanks for the info!