I'm playing with a similar designed based on a at90s2313 and a irl530. The result was very unsatisfactory. To get speed, it is necessary to use a high (35-45v) power supply and a chopper to control the current. A chopper can be implemented by adding a lm324 op amp to use as a pair of comparators to detect the coil current. With the o/p going to interrupts, the mcu can turn off the drive for a fixed time whenver the setpoint is exceeded.
I will try it this week as soon as I have time to write the program. |