IntroductionBackground ReadingExperiment #1: Run VI to Simultaneously Generate Four Digital SignalsExperiment #2: Increment the Position of a Unipolar Stepper Motor Using an Analog Current Amplification Circuit StepExperiment #3: Observe the Output of a Binary Counter Chip Experiment #4: Control the Angular Velocity of a Unipolar Stepper Motor Using an Analog Drive CircuitSaving FilesLaboratory Report Additional ReadingME 104 Sensors and Actuators Laboratory #7 Stepper Motors Department of Mechanical Engineering University of California, Santa Barbara (Rev. 2006)Introduction In this Laboratory, a LabVIEW VI for generating digital TTL signals is used to provide the stepping sequence for a four-phase unipolar stepper motor. You will then use a function generator and an analog drive circuit to control the rate of rotation of a unipolar stepper motor in full-step mode. The stepper motor you will use in this Laboratory is a four-phase unipolar stepper motor produced by Jameco Electronics (Part #166705). The motor requires a DC Supply Voltage of 12 V and a Current of 140 mA. The motor has a Step Angle of 3.8°, Phase Resistance of 84 Ω, and Phase Inductance of 16 mH. The phase and field coil schematic for this stepper motor is shown in Figure 1. stepper motor coil +12 φ1 φ2 φ3 φ4 wht/orange orange brown blue brown wht/brn Figure 1: Jameco stepper motor phase and field coil schematic. Colors refer to lead wires. Background Reading Please read the following material prior to this lab: 1. Histand and Alciatore, Introduction to Mechatronics, Section 6.3 and Sections 10.6. 2. Data Sheet, IRLIZ34N HEXFET Power MOSFET, International Rectifier. Available on melab share drive: Z:\ME 104\Lab 7 3. Data Sheet, 74LS191 Synchronous 4-Bit Binary Up/Down Counters with Mode Control. Available on melab share drive: Z:\ME 104\Lab 7 4. Data Sheet, 74LS86 Quad 2-Input Exclusive OR Gate. Available on melab share drive: Z:\ME 104\Lab 7 2Experiment #1: Run VI to Simultaneously Generate Four Digital Signals In this experiment, you will use a LabVIEW VI that simultaneously generates four digital TTL signals that can be used to provide the stepping sequence for a four-phase unipolar stepper motor. The PCI-6024E DAQ Board has one digital input/output port (P0) with eight channels, all of which are TTL (transistor-to-transistor logic). Of these eight channels, the first four channels (P0.0, P0.1, P0.2, and P0.3) have been configured to Read (acquire) TTL signals, while the last four channels (P0.4, P0.5, P0.6, and P0.7) have been configured to Write (generate) TTL signals. 1. Open Write_DigOut.vi from the melab share drive. The VI is shown in Figure 2. Figure 2. This VI generates four digital output signals that are used to provide the stepping sequence for a four-phase unipolar stepper motor. 2. Choose an appropriate* Digital Ground (D GND) pin on your CB-68LP connector block and provide (define) ground to that pin using the black (-) terminal of the “5 V FIXED 3 A” output from your Tektronix PS280 DC Power Supply*. You do not need to turn on the power supply. * Choose a D GND pin that is reasonably close to the four Digital I/O channels (pins) you are using. 33. For viewing purposes, connect Digital I/O Channel 4 (P0.4) and Digital I/O Channel 5 (P0.5) to your oscilloscope. (Use the Connector Pinout sheets at each station to determine pin number for each digital output channel.) 4. Run your VI by clicking the Run button. Press the different Phase buttons to toggle them between ON (high) and OFF (low) states. Using your oscilloscope display, verify that the outputs from Digital I/O Channel 4 (P0.4) and Digital I/O Channel 5 (P0.5) are what you expect them to be. 5. Now connect Digital I/O Channel 6 (P0.6) and Digital I/O Channel 7 (P0.7) to your oscilloscope and verify that the outputs from those two channels are what you expect them to be (i.e., repeat Step 3 above for those two channels). 6. Stop running the VI by clicking the Stop button. 7. Ask your TA to check that you have successfully completed Experiment #1. Experiment #2: Increment the Position of a Unipolar Stepper Motor Using an Analog Current Amplification Circuit In this experiment, you will use the LabVIEW VI to produce the stepping sequence for the Jameco four-phase unipolar stepper motor. The current from the Digital I/O Channels on the DAQ Board is not sufficient to drive the stepper motor. Therefore, before being sent into the stepper motor, the current from each of those digital channels must be amplified using a Power MOSFET. A power MOSFET is used to interface a low output current device such as a data acquisition board or computer port to another device (such as a stepper motor) that requires larger currents. The power MOSFET you will use in this laboratory is an IRLIZ34N HEXFET Power MOSFET manufactured by International Rectifier. (See Figure 3) SourceDrain Gate Figure 3. IRLIZ34N Power MOSFET * Since the ground terminal from the DC Power Supply has already been connected to your electronic breadboard, you can use the ground connection from that breadboard to define ground. 41. Build and connect the circuits shown in Figure 1 and Figure 4. Your gate phase (Gφ) signals will be generated by the Digital I/O Channels. Obtain Gφ1 from P0.4, obtain Gφ2 from P0.5, obtain Gφ3 from P0.6, and obtain Gφ4 from P0.7. S = SourceD = Drain G = Gate (P0.4) (P0.5) (P0.6) (P0.7)Figure 4. Current amplification circuit using Power MOSFET Your goal is to verify that the phase sequence shown in Table 1* does, in fact, induce 3.8° full-steps (increments) in shaft angular position. Table 1: Unipolar full-step phase sequence Step φ1φ2φ3φ41 ON OFF ON OFF 2 ON OFF OFF ON 3 OFF ON OFF ON 4 OFF ON ON OFF CCW CW 2. Open yourname_lab8_ex1.vi. 3. Press the Phase buttons so that they specify Step 1 (from Table 1) and then run your VI (once) by clicking the Run button. Your stepper motor shaft may move initially, but it will quickly come to a stop. * This is a direct copy of Table 10.1 from the Mechatronics textbook. 54. Now set (specify) Step 2 (from Table 1) and then run your VI (once) by clicking the Run button. The position of your stepper motor shaft should full-step (increment) once by 3.8° in the clockwise (CW) direction*. 5. Specify Step 3 (from Table 1) and then run your VI (once) by clicking the Run button. Verify that the position of your stepper motor