IR2110 problem please help

[capacitor1]

hi everyone

I have a problem with the circuit of ir2110 full bridge .

I copied the same circuit of tahmid from his site , it doesn't work great!!

the signal is like this :

the highest signal is +32V (like the +300 V in the tahmid blog circuit)
the second high signal is about +3V?????? ( this signal is seen in the HO2 where the signal should be zero)

and the mystrious thing , that when i change the duty cycle , the first part of graph increase and the second decrease or vice verca!!!!.

the circuit is like this :


and the Hin1=PWM ( 0 to 5v)
and the hin2 = 0V

please help me , what's the error ????????????????

thanx

 

[FvM]

and the Hin1=PWM ( 0 to 5v)
and the hin2 = 0V

It's not exactly clear which signals in your circuit you mean, because there's no "Hin1" or "Hin2".

But generally, the high side can't work without periodically switching the low side.

 

[daniel_edb]

As FvM wrote, you must periodically enable the low side. It is necessary to recharge C1,C2 and C5,C6. These capacitors are used as power supply for driver on high side. Frequency of switching is also important. If you work with very low frequency, C1,C2 (and C5,C6) will be discharged through gate resistors and driving will not work correct.

 

[capacitor1]

Hi friends

so sorry for delay

you saw guys that the Hin1 ( high side in 1 ) and Lin2( low side in 2) are connected to the same pin ( pin1 per example). and the Hin2 and Lin1 are also connected(to pin2)

from my pic :
what I should generate to attain the H bridge to pin1 and pin2
please Help

and sorry for delay