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Old 12-18-2014, 05:25 PM   #1482 (permalink)
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Originally Posted by cts_casemod View Post
The water pump is a good one, with the complementary temperature sensor input
Should allow the cooling system to adapt automatically to various driving environments. Stop/go traffic, cruising, racing, etc.

Originally Posted by cts_casemod View Post
Load indicator can be taken directly from the throttle, since the user commands torque...
Sounds good.
I was pondering the "user commands torque" bit as i am aiming to replicate the normal ICE driving environment as much is possible.
Just wanted to check my understanding of how i think the throttle will behave against some EVers actual experience.
With an ICE, giving 30% throttle gives more aggressive acceleration than say 10% throttle. So the EVs torque based throttle would replicate that.
But as the cars speed increases and the engine RPM increases, in an ICE motor the amount of fuel mixture delivered to each cylinder on each cycle reduces. So with a fixed throttle input of 30% the torque decreases as the RPM increases until an equilibrium is reached where the torque required to overcome wind/rolling resistance is balanced by the torque supplied by the motor. So now the car is cruising at a fixed speed and the throttle is still at 30%.
With an electric motor setup the 30% throttle will give a similar to ICE initial acceleration but holding the throttle at 30% will continue the torque delivery. The torque will not decrease with increased RPM because the controller is working hard to deliver the commanded torque so at some point you need to reduce the throttle input to decrease the torque delivered and achieve a steady speed cruise.
So some sort of RPM feedback to bias the throttle would be needed to have the EV throttle behave just like an ICE one?

Originally Posted by cts_casemod View Post
I could do that. but at this point it starts to make sense to isolate the boards, perhaps. I want to have a relatively small board. This would allow the code to be changed as per user needs. Would 8 outputs and 8 inputs (digital) be enough?
Should be heaps. Another thought would be to have some extra outputs on the display PCB to drive the unused lights/indicators in the instrument cluster so you could convey important information in a way that is easily noticed by the driver.
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