I'm a CSE undergrad (1st year). As a project for our Electronics Eng. course I decided to make a H-bridge motor driver and here is the schematic ( i actually donno what the Electrical Engineering terms are)

I just want to know is there any problem in the current design here... do mind that it's for our project submission purpose and not for industrial use..

Thank you for reviewing a noob's project XD

 

1N4148 diode is low current.
At the moment the MOSFETs on the left side are off. OK But the MOSFETs on the right side are both on. Not good.

 

The glaring problem is that there are no inputs shown. How do you expect it to control anything without inputs?

 

Q2 is upside down.
The IRFZ44N needs a Vgs of ~10V to switch the FET fully on.
Is the motor intended to be PWM-controlled?

 

You have 4 input pins shown, PIN1-PIN4.
That gives 16 possible combinations. Reduce that to 4 combinations using only 2 inputs.
Draw the truth-table of operation for 2 inputs.

 

Q2 is upside down.

What?

 

The IRFZ44N needs a Vgs of ~10V to switch the FET fully on.

 

is this meant to work only on 12V? if using wider supply you will want to add some limiting on Vgs. as stated before 1N4148 is a signal diode. what is the load this bridge is supposed to drive? It makes ZERO sense to use 50A mosfet and pad it with 0.2A diode. what is the frequency you plan to run this on? why not have all 4 inputs work the same way - input HIGH turns ON matching mosfet? then you can tie inputs on same side together...

 

1N4148 diode is low current.
At the moment the MOSFETs on the left side are off. OK But the MOSFETs on the right side are both on. Not good.

What diode you suggest?


Low side of the design is Active Low.. meaning they are on when grounded.

Thanks!

 

Q2 is upside down.
The IRFZ44N needs a Vgs of ~10V to switch the FET fully on.
Is the motor intended to be PWM-controlled?

Yes it is intended to be PWM controlled.

And I figured it out that it need actually 10V to turn it fully on. I actually have these in hand currently and therefore using for design. But i agree that logic level IC's are better here.

Thanks!

 

is this meant to work only on 12V? if using wider supply you will want to add some limiting on Vgs. as stated before 1N4148 is a signal diode. what is the load this bridge is supposed to drive? It makes ZERO sense to use 50A mosfet and pad it with 0.2A diode. what is the frequency you plan to run this on? why not have all 4 inputs work the same way - input HIGH turns ON matching mosfet? then you can tie inputs on same side together...

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1. No it meant to be varying volt between say 6-20V
2. 50A mosfets are in use here because I have those in my hand. But it will be kind if you suggest proper MOSFETs.
3. About the frequency I didn't understand.. I mean frequency of what?
4. And will think your last point

Thank You!!!!

 

What diode you suggest?

Yes it is intended to be PWM controlled.

1N4001 is a 1A 50V diode used for 60hz but good in the audio range. uF4001 is an ultra-fast 1A 50V diode. I use them at PWM frequencies under 500khz.
Because I don't know the PWM frequency and current, I cannot say.

 

You have 4 input pins shown, PIN1-PIN4.
That gives 16 possible combinations. Reduce that to 4 combinations using only 2 inputs.
Draw the truth-table of operation for 2 inputs.

Noted. Thanks.

 

Here is a link. I searched for 50 to 100V diodes and 1A to 6A and fast (below 50nS).
digikey
Most venders have a search engine to help. You can choose SMD or through hole and many choices.

 

Here is a link. I searched for 50 to 100V diodes and 1A to 6A and fast (below 50nS).
digikey
Most venders have a search engine to help. You can choose SMD or through hole and many choices.

What about this?

Thanks.

 

What about this?

40V 3A fast, low forward voltage. Looks good.