MoTeC Global Forum

Hello

I am trying to use an electromagnetic clutch on a prototype for the Shell Eco Marathon. I control the clutch voltage with a PWM auxilary output links to a MOSFET transistor. The settings for the output are now 5kHz frequency, 0 minimum duty cycle and 100 maximum duty cycle.

The problem is that when I test the Motec output voltage there is no voltage between 0 and 50% and 12V between 51% and 100%.

What is the solution to have a progressive voltage ?

Thanks

Well how about change the frequency, or the duty cycle, of the output and use a low pass filter to smooth it out?

Make sure you have output control type set to 0, PWM. if its 1 it will just switch.

What is the Shell Eco Marathon? What are you using the clutch for?


The Nissan VQ35HR control its variable exhaust cams with an electromagnetic clutch. They are more difficult to control than the normal hydraulic cam control method. They are also quite sensitive to temperature/oil temperature. PID settings for cold and warm engine would be completely different.

Hello

The solution was to change the aux output, since the aux2 doesn't support PWM on the high side (+12V).

The electromagnetic clutch is used instead of a centrufugal one.
For information about the Shell Eco Marathon : http://www.shell.com/home/content/ecomarathon/


Thank you the answers.