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A Collection of Bridge Drive Circuits
These circuits were collected from various sources during the design of my stepper drive system. Where possible, there are links to further information. I have not built all of these circuits, but have found them to be useful as references when designing an electronics drive package for my cnc router table.
An 8 microstep design from the Full data sheet on A3955 useful to 50 volts 1.5amps/phase.
An L297 L298 2Amp/phase step and direction controller.
A 5Amp/40Volt bridge by Bob Blick (see www.bobblick.com/bob/projects/hbridge/ for an excellent design article)
Two examples of linear constant current drive circuits for bipolar or unipolar drives. Wonderful handwarmers!
6 Amp / 60 Volt UC3637 bridge driver. Full data sheet on UC3637
Up to 3 Amp 55 Volt Bipolar Drive Full Data Sheet on LMD18200.pdf
An interesting all N channel bridge drive that is capacitively coupled.
A simple low voltage bridge design with MCU interface - drive those robot tank motors.
Bridge drive using opto isolators and separate high side driver supply.
A low voltage bridge design... no gate protection on upper fets (20v is death).
Note high value gate resistors, this is detrimental to fast turn on/off times.
A very nice looking dual bridge driver by New Japan Radio (was known as the Erricsson PBL 3776).
Full data sheet on NJM3776 I believe this
is the driver used by Dan Mauch in his 5 amp driver kits????. Future and Mouser are listed as suppliers,
but I have been unable to source this part.
This bridge is collection of my thoughts and research. The target is a 35 volt, 5 amp, 30khz bridge.
This bridge requires high voltage drive (motor voltage rail to rail). Turn off time is limited by the 33 ohm resistors
and the turn on time is limited by the 1k 1w and the 33 ohm resistors. Gates are protected
from overvoltage by the 12 volt 1n4742 zener diodes. Peak gate turn on current is calculated as I= V/R = (35-.2)/1033 = 34 ma. Turn off current is
calculated as I= V/R = (12-0.2)/33 = 358 ma. The turn off time will be approximately ten times as fast
as the turn on time. The current sense resistor is close to max power rating if you run the full 5 amps
( P=I*I*R = 5*5*0.1 = 2.5 watts ). You may want to increase the rating to 5 watts if you are running close to
a full 5amps. The sense resistor should be non inductive and have separate traces routed from each side of it to
to the chopper comparator. The 5.1k resistors should be 1/2 watt. Be sure to use the "A" series of the 2n2222A
and the 2n2907A rated at 60 volts, as the non-"A" versions are only rated for 40 volts.
If the drive is lost, all 4 fet switches are turned off.
With no drive supplied, both the 2n2222A and the 2n2907A are biased on which shuts the fets off.
In this case, the 1k resistor is basically across the 35 volt supply and will see 1.2 watts.
This should be a 2 watt part if you are running
a full 35 volts and expect to have open or floating circuits on the phase drive inputs.
During normal drive, this is not a problem as one of the transistors will be off and part of the power
is absorbed by one of the zener diodes. The 51k resistors on the fet gates are optional. They are there
to guarantee a gate pull down in case the smoke gets out of the driver transistor or 33 ohm resistor.
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