Maker Pro
Maker Pro

H-Bridge questions

J

James Lerch

Jan 1, 1970
0
Greetings All,

I'm assembling an H-Bridge based on this schematic:
http://dave.golfbuddys.com/hvguy/new/indheat/igbtindheat.gif

I had two questions for the group:

#1 IC2 and IC4, shouldn't these be 4421 inverting drivers?

#2 Is there anyway to avoid the two 1:1:1 transformers?


Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction, Testing, and Coating site)

Press on: nothing in the world can take the place of perseverance.
Talent will not; nothing is more common than unsuccessful men with talent.
Genius will not; unrewarded genius is almost a proverb.
Education will not; the world is full of educated derelicts.
Persistence and determination alone are omnipotent.
Calvin Coolidge
 
T

The Al Bundy

Jan 1, 1970
0
James Lerch said:
Greetings All,

I'm assembling an H-Bridge based on this schematic:
http://dave.golfbuddys.com/hvguy/new/indheat/igbtindheat.gif

I had two questions for the group:

#1 IC2 and IC4, shouldn't these be 4421 inverting drivers?

No, these are driven by the other output of the TL494. This output is
already inverted so no extra inverter is needed in the drive circuit.
#2 Is there anyway to avoid the two 1:1:1 transformers?

Yes, by a low and high side MOSFET/IGBT driver with a bootstrap. Look at
IR's site: www.irf.com
The only thing to keep in mind when using such low/high side driver IC is
that there is no isolation between the H bridge and driver/controller.

Al
 
J

James Lerch

Jan 1, 1970
0
No, these are driven by the other output of the TL494. This output is
already inverted so no extra inverter is needed in the drive circuit.


DOHHH, That was embarrassing :0
Yes, by a low and high side MOSFET/IGBT driver with a bootstrap. Look at
IR's site: www.irf.com
The only thing to keep in mind when using such low/high side driver IC is
that there is no isolation between the H bridge and driver/controller.

Ok, I decided to wind up a pair of transformers. Any suggestion on
what gauge wire to use?


Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction, Testing, and Coating site)

Press on: nothing in the world can take the place of perseverance.
Talent will not; nothing is more common than unsuccessful men with talent.
Genius will not; unrewarded genius is almost a proverb.
Education will not; the world is full of educated derelicts.
Persistence and determination alone are omnipotent.
Calvin Coolidge
 
P

Paul Burridge

Jan 1, 1970
0
press on: nothing in the world can take the place of perseverance.
Talent will not; nothing is more common than unsuccessful men with talent.
Genius will not; unrewarded genius is almost a proverb.
Education will not; the world is full of educated derelicts.
Persistence and determination alone are omnipotent.
Calvin Coolidge

Churchill replaced "determination" with "judgement" in his version of
this quote. Horses for course, I guess.
 
T

The Al Bundy

Jan 1, 1970
0
James Lerch said:
On Tue, 22 Jun 2004 23:32:05 +0200, "The Al Bundy"

DOHHH, That was embarrassing :0
It can happen :)
Ok, I decided to wind up a pair of transformers. Any suggestion on
what gauge wire to use?

A wire gauge around 26-22AWG should do the trick. Only designing a good gate
transformer takes some time. First you need to know the volts per
u(micro)second that you apply on the primary winding. With this value and
how many turns on the core you can calculate the peak flux swing in the
core.
This flux swing should be around 0.5x lower then the maximum peak flux
rating of the core. This means you must have some data of the core that you
will be using.
If you need many turns for a specific core to not let it saturate you also
need to calculate if all the windings will fit on that core. If not you will
need a bigger core.

But to ease the design some companies have standard gate drive transformers.
Such like http://www.pulseeng.com/
It saves allot of time if you want to do it right.

Good luck,
Al
 
R

ross

Jan 1, 1970
0
while this subject has been brought up I have a question
I need an h-bridge circuit for and automotive electric window motor
any suggestion on where to look

Thanx
 
Top