I wouldn't turn on fet1 and fet3 at the same time.

-----Original Message-----
From: pic microcontroller discussion list
[mailto:PICLIST@MITVMA.MIT.EDU]On Behalf Of juan manuel garofalo
Sent: Sunday, February 03, 2002 2:42 PM
To: PICLIST@MITVMA.MIT.EDU
Subject: [ee]: h bridges


                +24 v
        |               |
        |               |
      fet_1           fet_3
        |               |
     (a)|-----motor-----|
        |               |
        |               |
      fet_4           fet_2
        |               |
        |               |


Hi there,

Suppose that the bridge depicted is used to only to reverse the motor, not
using PWM.

Is it true that, when fet_1 & fet_2 are on, point (a) is not at ~zero volts,
and therefore you need a gate bias higher than 24v to turn fet_1 on ? I read
this is the case but i really don't get it why it's so. Anybody care to
explain it to me ?

Does Using PWM make any diference regarding bias for the fets ?

Thanks a lot!

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