Over heating H-bridge MOSFET (irf9540)?

[soheilpaper]

i have done the circuit in the pic :



from :
http://letsmakerobots.com/content/yet-another-fet-based-h-bridge?page=1

so two upper MOSFET (irf9540) will be overcharged and so heating but there is no power output for DC motor (VBat = 12v) and (v-A or V_B=12v)
so what do you think?!.
i simulated this circ in Proteus (combined with an IC555 for PWM and you could see its image in :




But it don't working in simulation too. in simulation the irf540 with or without enable and A & B input how 65mV as Vgs! my be if i change its biasing part it work.
And i how another Question :
What would be happended if i will drive a MOSFET with nominal Vgs (like 10V) and how no load in its drain .is it overheating!?
i think its don't work correctly in biasing of irf540 MOSFETs . so could you help me to make it correct.
Thanks a lot.

 

[D.A.(Tony)Stewart]

I guess your lesson is not to follow a poorly documented and defined design.

heat comes from two sources, Conduction Loss and commutation loss. Low RC on gate improves commutation time. low RdsOn improves conduction loss.

I"ll let you device a way to sort that out.


the secret is what was missing in the article.