Re: [CAD_CAM_EDM_DRO] Re: capacitor

The energy is in your case being dissipated as heat in the torque converter.
During deceleration both the engine output and the stored energy in the car
are turned into heat. This is like a linear servo controller. To slow down
the motor it applies a reverse drive, resulting in a high voltage drop
across the drivers and high current through them so they get hot.

Here is another thought experiment:
You are driving forwards in a manual transmission car and want to accelerate
backwards. Instead of grinding into reverse straight away, change down a
gear or two. Your forward momentum is now used to accelerate the engine.
Once your road speed has dropped you can pop it into reverse and use some of
that stored energy to accelerate the car backwards. Of course if you try to
decelerate too fast this way the engine will over-rev.

This is more the way normal H-bridge PWM controllers work. Some of the
energy released by decelerating the load is pumped back into the supply,
while the rest is lost as heat. This is often called regenerative braking.

Les Newell

> Les, Jon,
>
> I don't mean to belabor the point but once I have my teeth into
> something I have to take to its conclusion. That means I have to make
> sure I understand the underlying principle or have others show me
> where I am mistaken.
>
> I am making two assumptions:
>
> (1) "Energy return" during deceleration is not a given.
> (2) There is no difference between acceleration and deceleration.
>
> Both points are tied together in this thought experiment:
>
> Say you are in a car that is rolling backwards at 20 MPH and the
> transmission is in "drive". You apply torque (press the gas) to the
> drive wheels at a constant rate. The car decelerates, stops, then
> accelerates until you are going 20 MPH in the forward direction. Oh
> yeah, and your eyes are closed as well (don't try this at home folks,
> this is a trained professional driver).
>
> The questions are:
>
> (1) If "energy return" is a given, why are you pressing the gas pedal
> during deceleration?
>
> (2) Can you tell when deceleration ends and acceleration begins?
> Remember, your eyes are closed (no peeking).
>
> Mariss