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Old 05-03-2011, 03:46 PM   #342 (permalink)
flores
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Quote:
Originally Posted by DJBecker View Post
You forgot to add the caveat "with a suitably large inductor". I'm sure you know this, but not the casual reader.
I didn't. I'm fairly good with digital electronics, but this power electronics is fairly new to me.

Quote:
Originally Posted by DJBecker View Post
Without output smoothing, the Cougar will have bad behavior with many batteries. LiFePO batteries, which look pretty much like capacitors in the time frames involved, will absorb huge current pulses in the first few microseconds putting the controller at risk. Most lead-acid batteries will heat rather efficiently charge.
Dumb question: I thought that the capacitors smooth out the output voltage? How does an inductor help with this? And with inductor you mean a coil with a wire wrapped around/through it right?

Quote:
Originally Posted by DJBecker View Post
The Cougar runs the PWM at about 8KHz or 16KHz, which requires a pretty big inductor. It could be much smaller with a frequency 4x-10x higher. And a smaller inductor might have lower resistive losses, which could offset the higher switching losses. Perhaps.
How can I tell that i'm doing it right/have the right inductance? can this be measured? seen on a scope?

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