48V 20A H-Bridge Motor Driver

Thread Starter


Joined Dec 20, 2010
Hi All!
I'm trying to update my Unimat 3 lathe original motor to a 36v, 500w DC electric scooter motor. I went and ordered a 48V 500W switched-mode power supply unit for this bad boy, I'm going to make the motor work harder by running it at 48V. Since I'm planning to use an arduino to control its speed and position, I also ordered an optical encoder disk. Now all I need is a 48V 10.5A H-Bridge Motor Driver...here lies the problem: They are too expensive!
So I checked around for other options and found this:
"Universal DC10-60V PWM HHO RC Motor Speed Regulator Controller Switch 20A New" for under 5 dollar!
link: http://www.ebay.com/itm/291341338166
I'm thinking I can just use the H-bridge, discard or ignore its PWM signal and use the arduino's PWM instead, or some how "interface", work with it
So the question is: "Can I? Should I?"
Thanks in advance.


Joined Jul 18, 2013
Those controllers are uni-directional and use a 555 for PWM control, you could analogue control it in place of the pot, but you would need to use relay or other means for bi-directional control.

Thread Starter


Joined Dec 20, 2010
Thanks Max, You just saved me 5 bucks lol. How could I have not noticed that? Looks like i'm going to have to build my own, using mosfets....Arrgggghhh

Does anyone have a handy, reliable schematic for a high voltage, high current H-bridge using mosfets?


Joined Apr 5, 2008

Never run parts at their maximum ratings.
It is more practical to use about half the maximum ratings.