“Micro-Controller Based” DC Motor Controllers using PWM DC Motor Control Examples: Direction and speed control of DC motors Limiting the maximum current through the DC motor Incorporate safety features on controller board More effective and cost saving method to drive DC motors IGBT or SCR switching Control of up to 800A DC motors ”In circuit” programming of controller board Typical DC Motor Example: DC motor start up current – 450 Ampere DC motor maximum voltage – 300 Volt Typical DC Motor Driver Circuit Using an IGBT: IGBT Maximum Ratings – 1000 Volt, 1200 Ampere IGBT Mounted on a Heatsink Using High Current/Voltage Diodes to Block Back EMF from Motor Low Current (20mA) Isolated Control Circuit to Switch IGBT Typical Micro-Processor (Main CPU) Board for Control of DC Motor: Single “micro-controller” on PC board Programmable – With remote programmer Low current (20mA) PWM output to IGBT driver circuit Incorporate safety features such as: Motor “stall” protection Motor “slow start” Current limiting at 450 Ampere Speed limiting – 8km/h to 15km/h Operator protection Typical programmer unit for programming of main CPU board: Changing of main features on CPU board Download new firmware to main CPU LCD – 20 characters and 4 lines Keypad - 21 keys Wireless or wired interface to main CPU Battery powered or powered from CPU