On 03/21/2013 08:10 PM, Scott Dorsey wrote:
Bimmer Owner wrote:
On Thu, 21 Mar 2013 19:15:16 -0700, jim beam wrote:

that's why pwm is the better solution

Does pulse width modulation cause radio EMI?

It can if it's not properly filtered. And the reason why I think beam is
correct about this being a linear control is that there is no filtration
in there.

it's the heat sink that's the dead give-away. a pwm controller heatsink
would be 1/10th the capacity. or less.



My guess is that the cost of proper filtering and shielding makes the pwm
controller cost more than the linear controller in this case, which is
probably why they went the linear route.

i think the cost of that honking great heatsink significantly exceeds
the cost of a couple of extra inductors and caps.


--
fact check required