H-bridge simplification

[rocky79]

Hello all,

I am building an economical H-bridge circuit using minimum component counts, I found this schematics online that I want to simplify little bit, where I thought I wouldn't need trans Q6 and the 2.2K ohms resistor but instead drive the PMOS AND THE NAND GATE directly from the microcontroller pin.

That should work, unless I am missing something. Your input is appreciated.

 

[sky_123]

I am building an economical H-bridge circuit using minimum component counts

This won't work (very well). Firstly, you've got a pullup to 12V on your PIC - not very nice.
Secondly, it's not a good circuit anyway.

A H-bridge is never economical in terms of component count if you try to implement in discrete components.

You're better off with an off-the-shelf IC - I don't use them, but L293 or whatever.

EDIT: Also, your top of the bridge will never fully turn off. If you really want to go down the road
of using this circuit, then you need to leave the Q6 in place.

 

[rocky79]

You're right, didn't pay attention to the 12v. I see, I will leave Q6 in place.

Secondly, it's not a good circuit anyway.

Beside leaving Q6 in place, why it isn't a good circuit? I am looking to do a simple full forward and full reverse, no PWM is involved.