|
[DPRG] Queries about the McManis H bridge
Subject: [DPRG] Queries about the McManis H bridge
From: DeltaGraph at aol.com
DeltaGraph at aol.com
Date: Sat Oct 7 16:48:26 CDT 2006
Here is a shot at starting to answer some of your questions, before the
smart people kick in:
1. Hmm. good question
2/3 Total flyback power is a function of current and inductance.
I am pretty sure the current flow into the flyback diode can be approximated
by the "ON" current and voltage drop product (Power = Voltage Drop x
Current) of the transistor. So, the absolute worst case would increase power
dissipation in the transistor by a factor of 2x over what you would encounter
driving a pure resistive load (no inductive flyback).
The flyback diodes prevent the voltage spike that would occur and damage
your transistors, but of course will be helping to heat up the transistors.
.. Hence you might not need to add flyback diodes to transistors already so
equipped.
If things are not getting too hot you should be good to go.
A real good understanding for the above comes in with AC circuit analysis
where they get into very good quantitative models of power stored in inductors..
and what happens when current changes when you open and close switches...
Hmm 25 years ago for me.
Maybe someone could toss you some good key phrases...
.. the internet knows almost everything now..
4. Hmm. Ran out of time...
Ron
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://list.dprg.org/pipermail/dprglist/attachments/20061007/1dd6eb3d/attachment.html
More information about the DPRG mailing list
|
