Hi,
I am trying to drive 24v 120w dc motor using H-bridge of IRF840 driven by IR2110.at Appr.=11khz pwm frequency.I am using PIC184431 to control the motor.
I am using 22.1184 mhz crystal & PR2=124 with timer2 prescaler =4.
The circuit works fine.
But I encounter following problems.
I am trying to drive 24v 120w dc motor using H-bridge of IRF840 driven by IR2110.at Appr.=11khz pwm frequency.I am using PIC184431 to control the motor.
I am using 22.1184 mhz crystal & PR2=124 with timer2 prescaler =4.
The circuit works fine.
But I encounter following problems.
- At resistive loads it works fine i.e I can get linear dc o/p from 0 to 23 corresponding to 0% to 95% of duty cycle. But when motor is connected it doesn't start till duty cycle = appr.40%.then I get the linearity.
- The circuit works fine at lighter loads.At higher load the mosfets get heated up and even at 95% of duty cycle unable to carry the load.