Hi, i am new in this forum and i have a big problem with my project.
The H bridge is functioning normally for a frequency of 50Hz but when I put a frequency of 10khz seems to lose references and pwm floats. I believe the problem is in the bootstrap capacitor. Thanks for your help.

 

i forgot, i am using mosfet irfp 264.

 

If you have oscilloscope, then you can measure the HO(Pin 7) and LO(Pin 1) of the IR2110.
You can also compare the waveform between Hin(Pin 10) and HO(Pin 7), and compare the Lin(Pin 12) and LO(Pin 1).

You have to measure IR2110 of two sides, whatever on the Left side or Right side.

And then you can measure the plus(+) side of D1~D4.

 

Read section 3: http://www.irf.com/technical-info/appnotes/an-978.pdf

Btw, the zener diodes have up to 10% tolerances.

 

Kind of unusual to use PWM on both the high and low side of the H-bridge at he same time. Most time just the low side is PWMed and the high side is just on during the cycle. If both high and low are not perfectly timed the motor won't be activated. It wouldn't be critical at the low frequency, but could/would be at the higher frequency.

 

Kind of unusual to use PWM on both the high and low side of the H-bridge at he same time. Most time just the low side is PWMed and the high side is just on during the cycle. If both high and low are not perfectly timed the motor won't be activated. It wouldn't be critical at the low frequency, but could/would be at the higher frequency.

Read section 3: http://www.irf.com/technical-info/appnotes/an-978.pdf

Btw, the zener diodes have up to 10% tolerances.

If you have oscilloscope, then you can measure the HO(Pin 7) and LO(Pin 1) of the IR2110.
You can also compare the waveform between Hin(Pin 10) and HO(Pin 7), and compare the Lin(Pin 12) and LO(Pin 1).

You have to measure IR2110 of two sides, whatever on the Left side or Right side.

And then you can measure the plus(+) side of D1~D4.

Thanks for the help of you, I discovered that when I put a load of 1kOhm he does not work for high frequencies, but when I put a resistance of 100ohms it works perfectly, ie reducing the resistance the floating ground is clearer. The information obtained by the oscilloscope. When I connect the pwm 1 PWM2 this grounded. in section 3 about "HOW TO SELECT THE COMPONENTS BOOTSTRAP" I do not know how to find some variables. Again thanks for the help.

 

There are 4 4.7uf on the circuit, try to use 0.47uf to replace them, and try it..