RE: SSTC questions

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Mccauley, Daniel H by way of Terry Fritz <teslalist-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>


1) Why do people "disable" the body diodes of the FETs?  With a full bridge,
there shouldn't be a problem with too much current through the diodes, next
to none if the switching of the FETs is done correctly and there is at least
one rectifying diode on the input.

Sorry, forgot to credit the following paragraph which was taken from Richie
Burnett's Website:

"(If no path is provided for the free-wheeling load current when both
switches are open, then a large voltage pulse is developed. This is often
referred to as "back-EMF" and is encountered with many inductive loads such
as motors and solenoids, when the current is interrupted abruptly.) The
action of the free-wheel diodes can be thought of as clamping the back EMF
to the supply rails."