loose-electron
Senior Fellow
Offline
Best Design Tool = Capable Designers
Posts: 1638
San Diego California
|
4 diodes are needed (across each of the 4 driver transistors)
If its a PCB level design use schottky devices so the path of current is thru the diodes and not thru the transistors. (slightly lower forward biased on voltage)
The 4 diodes limit your range of operation to a diode junction above-below the power-ground rails.
Plus a series RC snubber across the motor itself. (R equals motor winding resistance, C depends on application need)
H bridge drivers, since you reverse polarity, doesn't allow the easy use of a flyback diode.
Word of caution - watch the control of your top-bottom drivers to avoid shoot-thru, when top and bottom drivers are both on - on one side of the H-bridge. Great potential for a smoke show.
|