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Topic: H Bridge design (Read 2 times) previous topic - next topic


Hello all,

Although I have been playing around with the Arduino for a while now I have always used pre manufactured circuits.
I decided to break the habit with the "simple" H-Bridge.
I was wondering if someone could review it for me and maybe spot any major errors (think my cap value is wrong?).
I have attached my design schematic and design calcs which are entirely based on this article:


Many thanks in advance for you help,




Sorry it will not work. There is no way to control those top FETs. Normally you would have a P-channel FET at the top and a transistor or other FET driving it.

I haven't read you link but either it is wrong or you are not understanding things.
A 35A H-bridge is too big for a first design, it will fry.


Hi Grumpy_Mike,

Thanks for your comments, can you please clarify what will fry?

Please see this link, the Arduino is connected directly to the gate of the mosfet?


Thanks again for your comments.



H bridges need some kind of dedicated driver chip to control the Hi side Fets so that they fully saturate when turned on.
As the previous poster indicated, your circuit wont turn the hi side fets on.
Have a look at using 2 of these devices http://www.irf.com/product-info/datasheets/data/ir2104.pdf
as the Fet drivers.
They also provide the shoot thru protection needed to stop the fets frying when switching.

Runaway Pancake

"Hello, I must be going..."
"You gotta fight -- for your right -- to party!"
Don't react - Read.
"Who is like unto the beast? who is able to make war with him?"

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