User Manual TU004 - Bipolar Stepper Motor driver For any questions, concerns, or issues; submit them to support@tu-eshop.com Technology Uncorked LLP provides the enclosed product(s) under the following conditions: This evaluation board/.kit is intended for use in Engineering development, demonstration, and education or evaluation purposes only and is not considered by Technology Uncorked LLP to be finished end project fit for general consumer use. Persons handling the product(s) must have basic knowledge of electronics, should have experience and training in handling electronic components and assemblies, using standard engineering practices. As such, goods being provided are not intended to be complete in terms of required design, marketing and/or manufacturing related protective considerations, including product safety, environmental measures typically found in end products that incorporate such semiconductor components or circuit board. This evaluation board/kit does not fall within the scope of European Union directives regarding electromagnetic compatibility, restricted substances (RoHS), recycling (WEEE), FCC, CE or UL and therefore may meet the technical requirement of these directives or other related directives. The user assumes all responsibility and liability for proper and safe handling of the goods. Further the user indemnifies Technology Uncorked LLP from all claims arising from the handling or use of the goods. Due to the open construction of the product, it is the user s responsibility to take any and all appropriate precautions with regard to electrostatic discharge (ESD). EXCEPT TO THE EXTENT OF THE INDEMNITY SET FORTH ABOVE, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES. Technology Uncorked LLP currently deals with a variety of customers of products, and therefore our arrangement with the user is not exclusive. Technology Uncorked LLP assumes no liability for application assistance, customer product design, software performance, or infringement of patents or services described herein. Please read the User s guide and, specially, the warnings and restrictions notice in the user guide prior to handling the product. This notice contains important safety information about temperatures and voltages. TU Technology Uncorked LLP. All Rights Reserved. Page 1
No license is granted under any patent rights or other intellectual property right of Technology Uncorked LLP covering or relating to any machine, process, or combination in which such Technology Uncorked LLP products or services might be or are used. Mailing address: TU Technology Uncorked LLP D-125, Sushant Lok-3, Sector 57 Gurgaon, Haryana, 122001 REVISION HISTORY Version Date Reviser Comments/ change details 1.0 7 th Technology Dec 2010 Version release 1.0 Uncorked TU Technology Uncorked LLP. All Rights Reserved. Page 2
Contents List of Figures... 3 About TU Bipolar stepper motor driver... 4 Basic interface description... 4 Electrical characteristics... 5 Protections:... 5 Usage restrictions... 6 Appendix... 7 References and further reading... 7 List of Figures Figure 1: Position of pin no. 1 in various connectors... 4 Figure 2: Interfacing connection... 4 Figure 3: Hold current settings and winding current control... 6 TU Technology Uncorked LLP. All Rights Reserved. Page 3
About TU Bipolar stepper motor driver Basic interface description Position of pin no. one in various connectors J2: Power supply connector Figure 1: Position of pin no. 1 in various connectors J1: Connection to motor J3: Motor control R11: Pot for control voltage setting Figure 2: Interfacing connection TU Technology Uncorked LLP. All Rights Reserved. Page 4
Interface connections: J1: Motor control output Pin no. 1: Control output A Pin no. 2: Control output *A Pin no. 3: Control output B Pin no. 4: Control output *B J3: Motor control inputs Pin no. 1: Ground Pin no. 2: Control input A Pin no. 3: Control input B Pin no. 4: Control input *A Pin no. 5: Control input *B Pin no. 6: Hold input (active high) Pin no. 7: Motor enable (active high) J2: Power supply connector Pin no. 1: Motor Vcc Pin no. 2: Ground Pin no. 3: Ground Pin no. 4: Logic Vcc Electrical characteristics Sl no. Typical Max Mininum Logic Vcc +5V +7V +3.3V Motor Vcc +12V +24V Logic Vcc + 2.5V Control inputs +5V +7V +3.3V Winding current Programmable via R11 2.3 Amps (unfused) 1.2 Amps Protections: This motor driver comes with hardware based chopping mode current control protection system for precise control of winding current. Maximum winding current is programmable and can be set by turning potentiometer R11 while checking control voltage (refer Figure) probing any of the pin no. 3 or 5 of comparator IC U3 (LM393). TU Technology Uncorked LLP. All Rights Reserved. Page 5
Winding current is governed by following equation: I = V/R Where V is Control Voltage (230mV to 120mV programmable via potentiometer R11) I is winding current R is current sensing resistor (0E1Ω) Usage restrictions Figure 3: Hold current settings and winding current control This rugged bipolar stepper motor driver incorporates chopping mode current control. Refer Figure (3) Vref in the circuit is 2.5 Volts. When R11 (10KΩ) is set to x0, control voltage is 230 mv. This corresponds to winding current of 2.3 Amps. At this setting, even enabling hold signal (Active high) will result in holding current of 1.15 Amps. When R11 (10KΩ) is set to x 1.0, control voltage is 120 mv. At this setting, enabling hold signal (Active high) will result in holding current of 0.6 Amps. User is advised to exercise caution while using this motor driver with motors having low DC winding resistance. Best way to use this motor driver is to set the control current to the rated winding current. For e.g. if the motor is rated for 1 amp/phase, control voltage should be set to 100 mv (R3 set to x0.1). With this setting, if hold signal is applied (Active high) holding current value would be 500 ma (R13 parallel to R15). For any questions, concerns, or issues; submit them to support@tu-eshop.com TU Technology Uncorked LLP. All Rights Reserved. Page 6
Coil B Coil *B Appendix Bipolar motors have a single winding per phase. The current in a winding needs to be reversed in order to reverse a magnetic pole, so the driving circuit must be more complicated; typically with an H-bridge arrangement. There are two leads per phase, none are common. Coil A Coil *A M Because windings are better utilized, they are more powerful than a unipolar motor of the same weight. This is due to the physical space occupied by the windings. A unipolar motor has twice the amount of wire in the same space, but only half used at any point in time, hence is 50% efficient (or approximately 70% of the torque output available). For high positional reliability and long life of these motors in industrial and robotics applications, it is important to control the winding current in each winding independently. References and further reading Application note 2: Motors for Robotics and automation TU Technology Uncorked LLP. All Rights Reserved. Page 7