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Unread 04-05-2012, 12:01
rbmj rbmj is offline
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Re: Non-FRC Motor Controller?

Quote:
Originally Posted by Ether View Post
That's what the Vics and the Jags do. But the circuit must be designed and controlled properly, using appropriate FETs.

See page23, and page19 Figure 4-4, of this document:

http://www.ti.com/lit/ug/spmu130c/spmu130c.pdf


So, looking at figure 4-4, is this interpretation correct? The basic "OFF" state is q2g and q4g high. To go forward, q1g goes high, then after a little q2g goes low. Back off, q2g high, then q1g low. Reverse, q3g high, then q4g low. Back off again, q4g high, then q3g low. At each "then" is a small delay.

Then what are those zener diodes for (assuming I'm identifying them correctly)? Just in case there's a switching delay that isn't supposed to happen the MOSFETs don't get fried?

And then I can infer there's an oscillator that drives a clock for the whole thing? And the PWM signal is somehow fed into this oscillator that changes the frequency (and forward/reverse)?

Am I understanding this correctly? At this point, it's just theoretical (clearly that's above my skill level), but it's still interesting to understand how all of those "black boxes" work.

EDIT: @techhelpbb - thanks for the link! The links earlier up in the topic were very helpful - I think they give me enough information to make an informed decision.

Last edited by rbmj : 04-05-2012 at 12:04.