HELLO AGAIN THIS IS WILLIE L. MCCAIN I HAD SENT IN A REQUEST EARLIER TODAY ABOUT A PART P/N DRV8844 FOR A NEW DESIGN FOR MOTOR CONTROL , BUT AS I LOOK AT THE TI SITE AGAIN I FOUND A BETTER PART OF USE THE DRV8801 ITS SMALLER MUCH BETTER CONTROL OF WHAT I NEED AND I THINK THIS WOULD BE A BETTER PART TO USE FOR ALL MY MOTOR DRIVE APPLICATION , I WILL BE USING THE PART AS A MAIN DRIVER FOR AIRCRAFT ACTUATOR , OPEN AND CLOSE SHUTOFF VALVE FOR ENGIN START , WING FLAP ACTUATOR CONTROLLER , FOR TEST FIXTURES THERE WILL BE ABOUT 5 DEVICE'S PER BOARD PARRELLED WITH AGAIN FROM EACH OUTPUT OF THE DRIVER A .1 OHM CURRENT SENSE RESISTOR IN SERIES WITH EACH OUTPUT, AND THAN ALL THE OUTPUT AT A COMMON NODE WILL BE TIED TOGETHER FOR THE OUT+ / AND THE OUT - OUTPUTS AS REQUIRED , NOW TO GO A LITTLE FURTHER ON THE SUBJECT SINCE
IAM SURE WHAT I WILL BE USING IN THE DESIGNS I WILL USE A SIMPLE PWM DRIVER SO I WILL HAVE THE ON AND OFF CLOCK TO THE PART, NOW I WILL CONTROL THE PHASE INPUT ON THE DRV8801 FOR THE DIRECTION, AS FAR AS THE PWM TYPE NOT SURE AS OF NOW BUT STILL IF I USE VOLTAGE MODE I WILL SAMPLE THE OUTPUTS FROM THE DRIVER AND FILTER THEM AND FEED IT BACK TO THE PWM FOR REGULATION, SO BY VARING THE FEEDBACK SIGNAL I CAN CONTROL THE SPEED OF THE MOTOR ARE ACTUATOR, AND IF ITS A CURRENT TYPE I CAN SAMPLE THE SENSE CURRENT FROM THE SENSE RESISTOR AND FEED IT BACK TO THE PWM GENERATOR DEVICE AND VARY THE REF VOLTAGE TO THE ERROR AMP THE SET THE SPEED, I WILL HAVE DEADTIME CONTROL SO I CAN LIMIT THE MAX SHORT CIRCUIT CURRENT AND ADD OTHER FEATURES
OVERVOLTAGE SD.
OVER CURRENT SD.
OVERTEMP SD.
BE ABLE TO SET NORMAL RUN CURRENT LIMIT SO THAT AS THE MOTOR START UP IF ITS OVER A SET AMOUNT IT WILL SHUT DOWN AND TRIGGER A ALARM TO INDICATE THE MOTOR IS DEFECTIVE , BAD, SHORTED OR IF IT DOSNT START IN X-AMOUNT OF TIME THE WINDING IS OPEN WITH ALARM.
NOW DO YOU THINK THAT IF THE PWM GENERATOR IS A / ARE OUTPUT'S PHASES ARE JUST USE A REGULAR PWM TYPE OUTPUT WHERE THE CLOCK ARE THE SAME BUT THE PEROID CHANGES.
AND WOULD A CURRENT TYPE BE BETTER THAN USING A VOLTAGE MODE PWM ARE PHASE GENERATOR
AND WOULD 20 TO 25 KHZ BE A GOOD FREQ TO RUN AT TO MAKE SURE THAT AT FULL SPEED ARE MAX PWM THE MOTOR WILL RUN AT THE CORRECT RPM AS WELL
LET ME NO WHAT YOU THINK,
WILLIE