### Unipolar Drive Circuit Simulation using PSpice

1. Unipolar Stepping Motor Drive Circuit Simulation PSpice Version VCC VCC VCC VCC CLK D1 Vcc R1 U9 DIODE 12 CLK 1k FA S1 A A B FA + + 0 U5 - - RON = {RON} Acom Bcom 0 /FA S AND REF + 0 /A /B /FB - + - U1 UNI-POLAR_STEP_MOTR FB FB. VCC L = 2.5M HY S_I-CTRL R = 4.2 U10 VHY S = {VHY S} D2 1-PHASE U8 I_SET = {I_SET} DIODE PPS = 100 /FA S2 /A + + - - U4 RON = {RON} S AND REF + 0 - + - FB. VCC HY S_I-CTRL VHY S = {VHY S} D3 U7 I_SET = {I_SET} DIODE /FB S3 /B + + - - U3 RON = {RON} S AND REF + 0 - + - FB. VCC HY S_I-CTRL VHY S = {VHY S} D4 U6 I_SET = {I_SET} DIODE FB S4 B + + U2 - - RON = {RON} S AND REF + 0 - + - FB. HY S_I-CTRL VHY S = {VHY S} PARAMETERS: I_SET = {I_SET} PARAMETERS: I_SET = 0.5 RON = 10m VHY S = 0.1 All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 1
2. Unipolar Stepping Motor Drive Circuit Contents 1. Concept of Simulation 2. Unipolar Stepping Motor Drive Circuit 3. Unipolar Stepping Motor 4. Switches 5. Signal Generator 6. Hysteresis-Based Current Controller 7. Unipolar Stepping Motor Drive Circuit (Example) 7.1 One-Phase Sequence Drive, IPHASE=0.5A, IRIPPLE=0.1A 7.2 Two-Phase Sequence Drive, IPHASE=0.5A, IRIPPLE=0.1A 7.3 Half-Phase Sequence Drive, IPHASE=0.5A, IRIPPLE=0.1A 8. Drive Circuit Efficiency All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 2
3. 1.Concept of Simulation Block Diagram: Control Unit Driver Unit: Switches Stepping (e.g. Microcontroller) (e.g. Hysteresis- (e.g. FET, Motor Based Controller) Diode) Sequence: Parameter: • One-Phase Parameter: Parameter: •L • Two-Phase • I_SET • Ron •R • Half-Step • HYS Models: U2 VCC CLK CLK CLK FA FA FA FA Ctrl_A A B D1 DIODE /FA /FA /FA AND U1 S1 Acom Bcom Ctrl_A + + A /FB /FB /FB REF + - - RON = 10m S /A /B FB FB FB - + - U? U? U? U? FB. 0 UNI-POLAR_STEP_MOTR 1-PHASE 2-PHASE HALF-STEP HY S_I-CTRL L = 2.5M PPS = 100 PPS = 100 PPS = 100 VHY S = {VHY S} R = 4.2 I_SET = {I_SET} All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 3
4. 2.Unipolar Stepping Motor Drive Circuit Signal generator Hysteresis Based Current Switches Unipolar Stepping Motor Supply Voltage CLK Controller VCC VCC VCC VCC D1 Vcc R1 U9 DIODE 12 CLK 1k FA S1 A A B FA + + 0 U5 - - RON = {RON} Acom Bcom 0 /FA S AND REF + 0 /A /B /FB - + - U1 UNI-POLAR_STEP_MOTR FB FB. VCC L = 2.5M HY S_I-CTRL R = 4.2 U10 VHY S = {VHY S} D2 1-PHASE U8 I_SET = {I_SET} DIODE PPS = 100 /FA S2 /A + + - - U4 RON = {RON} S AND REF + 0 - + - FB. VCC HY S_I-CTRL VHY S = {VHY S} D3 U7 I_SET = {I_SET} DIODE /FB S3 /B + + - - U3 RON = {RON} S AND REF + 0 - + - FB. VCC HY S_I-CTRL VHY S = {VHY S} D4 U6 I_SET = {I_SET} DIODE FB S4 B + + U2 - - RON = {RON} S AND REF + 0 - + - FB. HY S_I-CTRL VHY S = {VHY S} PARAMETERS: I_SET = {I_SET} PARAMETERS: I_SET = 0.5 RON = 10m VHY S = 0.1 All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 4
5. 3.Unipolar Stepping Motor A B • The electrical equivalent circuit of each phase consists of an inductance of the phase winding series with Acom Bcom resistance. /A /B • The inductance is ideal (without saturation U1 characteristics and the mutual inductance between UNI-POLAR_STEP_MOTR phases) L = 2.5M R = 4.2 • The motor back EMF is set as zero to simplified the model parameters extraction. Input the inductance and resistance values (parameter: L, R) of the stepping motor, that are usually provided by the manufacturer datasheet, to generally model the phase winding. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 5
6. 4.Switches VCC • A near-ideal DIODE can be modeled by using spice D1 primitive model (D), which parameter: N=0.01 DIODE RS=0. S1 Ctrl_A + + A - - RON = 10m S • A near-ideal MOSFET can be modeled by using 0 PSpice VSWITCH that is voltage controlled switch. The parameter RON represents Rds(on) characteristics of MOSFET, that are usually provide by the manufacturer datasheet. The value could be about 10m to 10 ohm. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 6
7. 5.Signal Generator The signal generators are used as a microcontroller capable of generating step pulses and direction signals for the driver. There are 3 useful stepping sequences to control unipolar stepping motor One-Phase (Wave Drive) CLK FA CLK FA CLK FA • Consumes the least power. /FA /FA /FA • Assures the accuracy regardless of the winding imbalance. /FB /FB /FB FB FB FB Two-Phase (Hi-Torque) U? U? U? • Energizes 2 phases at the same time. 1-PHASE 2-PHASE HALF-STEP PPS = 100 PPS = 100 PPS = 100 • Offers an improved torque-speed result and greater holding torque. Input PPS (Pulse Per Second) as a clock pulse speed(frequency). Half-Step • Doubles the stepping resolution of the motor. • Reduces motor resonance which could cause a motor to stall at a resonant frequency. • Please note that this sequence is 8 steps. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 7
8. 5.1 One-Phase Sequence 5.0V Clock 2.5V 0V V(CLK) 5.0V Phase A2.5V ON 0V V(FA) 5.0V Phase /A 2.5V ON 0V V(/FA) 5.0V Phase B2.5V ON 0V V(FB) 5.0V Phase /B SEL>> ON 0V 0s 40ms 80ms V(/FB) 1 Sequence Time All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 8
9. 5.2 Two-Phase Sequence 5.0V Clock 2.5V 0V V(CLK) 5.0V Phase A2.5V ON 0V V(FA) 5.0V Phase /A 2.5V ON 0V V(/FA) 5.0V Phase B2.5V ON 0V V(FB) 5.0V Phase /B SEL>> ON ON 0V 0s 40ms 80ms V(/FB) 1 Sequence Time All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 9
10. 5.3 Half-Step Sequence Clock 4.0V 2.0V 0V V(CLK) 5.0V Phase A2.5V ON 0V V(FA) 5.0V Phase /A 2.5V ON 0V V(/FA) 5.0V Phase B2.5V ON 0V V(FB) 5.0V Phase /B SEL>> ON 0V 0s 80ms 160ms V(/FB) 1 Sequence Time All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 10
11. 6.Hysteresis-Based Current Controller U2 FA • Controlled by the signal from the Ctrl_A microcontroller. AND U1 • Generate the switch (MOSFET) drive signal REF + - + - by comparing the measured phase current FB. with their references. HY S_I-CTRL VHY S = 0.1 I_SET = 0.5 Input the reference value at the I_SET (e.g. I_SET=0.5A) to set the regulated current level. The hysteresis current value is set at the VHYS (e.g. VHYS=0.1A). All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 11
12. 7.1 One-Phase Sequence Drive, IPHASE=0.5A, IRIPPLE=0.1A VCC VCC VCC VCC CLK D1 Vcc R1 U9 DIODE 12 CLK 1k FA S1 A A B FA + + 0 U5 - - RON = {RON} Acom Bcom 0 /FA S AND REF + 0 /A /B /FB - + - U1 UNI-POLAR_STEP_MOTR FB FB. VCC L = 2.5M HY S_I-CTRL R = 4.2 U10 VHY S = {VHY S} D2 1-PHASE U8 I_SET = {I_SET} DIODE PPS = 100 /FA S2 /A + + - - U4 RON = {RON} S One-Phase AND + REF 0 Step Sequence - + Generator (100 - FB. VCC pps) HY S_I-CTRL VHY S = {VHY S} D3 U7 I_SET = {I_SET} DIODE /FB S3 /B + + - - U3 RON = {RON} S AND REF + 0 - + - FB. VCC HY S_I-CTRL VHY S = {VHY S} D4 U6 I_SET = {I_SET} DIODE FB S4 B + + U2 - - RON = {RON} S AND REF + 0 - + - FB. HY S_I-CTRL VHY S = {VHY S} *Analysis directives: PARAMETERS: I_SET = {I_SET} PARAMETERS: I_SET = 0.5 VHY S = 0.1 RON = 10m .TRAN 0 40ms 0 10u All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 12
13. 7.1 One-Phase Sequence Drive, IPHASE=0.5A, IRIPPLE=0.1A 5.0V Clock 2.5V 0V V(CLK) 5.0V 1.0A 1 2 Phase A Current I_HYS=0.1A 2.5V 0.5A >> I_SET=0.5A 0V 0A 1 V(FA) 2 -I(U1:A) 5.0V 1.0A 1 2 Phase /A Current 2.5V 0.5A >> 0V 0A 1 V(/FA) 2 -I(U1:/A) 5.0V 1.0A 1 2 Phase B Current 2.5V 0.5A >> 0V 0A 1 V(FB) 2 -I(U1:B) 5.0V 1.0A 1 2 Phase /B Current 2.5V 0.5A SEL>> 0V 0A 0s 10ms 20ms 30ms 40ms 1 V(/FB) 2 -I(U1:/B) Time All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 13
14. 7.2 Two-Phase Sequence Drive, IPHASE=0.5A, IRIPPLE=0.1A VCC VCC VCC VCC CLK D1 Vcc R1 U9 DIODE 12 CLK 1k FA S1 A A B FA + + 0 U5 - - RON = {RON} Acom Bcom 0 /FA S AND REF + 0 /A /B /FB - + - U1 UNI-POLAR_STEP_MOTR FB FB. VCC L = 2.5M HY S_I-CTRL R = 4.2 U10 VHY S = {VHY S} D2 2-PHASE U8 I_SET = {I_SET} DIODE PPS = 100 /FA S2 /A + + - - U4 RON = {RON} S Two-Phase AND + REF 0 Step Sequence - + Generator (100 - FB. VCC pps) HY S_I-CTRL VHY S = {VHY S} D3 U7 I_SET = {I_SET} DIODE /FB S3 /B + + - - U3 RON = {RON} S AND REF + 0 - + - FB. VCC HY S_I-CTRL VHY S = {VHY S} D4 U6 I_SET = {I_SET} DIODE FB S4 B + + U2 - - RON = {RON} S AND REF + 0 - + - FB. HY S_I-CTRL VHY S = {VHY S} *Analysis directives: PARAMETERS: I_SET = {I_SET} PARAMETERS: I_SET = 0.5 VHY S = 0.1 RON = 10m .TRAN 0 40ms 0 10u SKIPBP .OPTIONS ITL4= 40 All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 14
15. 7.2 Two-Phase Sequence Drive, IPHASE=0.5A, IRIPPLE=0.1A 5.0V Clock 2.5V 0V V(CLK) 5.0V 1.0A 1 2 Phase A Current I_HYS=0.1A 2.5V 0.5A >> I_SET=0.5A 0V 0A 1 V(FA) 2 -I(U1:A) 5.0V 1.0A 1 2 Phase /A Current 2.5V 0.5A >> 0V 0A 1 V(/FA) 2 -I(U1:/A) 5.0V 1.0A 1 2 Phase B Current 2.5V 0.5A >> 0V 0A 1 V(FB) 2 -I(U1:B) 5.0V 1.0A 1 2 Phase /B Current 2.5V 0.5A SEL>> 0V 0A 0s 10ms 20ms 30ms 40ms 1 V(/FB) 2 -I(U1:/B) Time All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 15
16. 7.3 Half-Phase Sequence Drive, IPHASE=0.5A, IRIPPLE=0.1A VCC VCC VCC VCC CLK D1 Vcc R1 U9 DIODE 12 CLK 1k FA S1 A A B FA + + 0 U5 - - RON = {RON} Acom Bcom 0 /FA S AND REF + 0 /A /B /FB - + - U1 UNI-POLAR_STEP_MOTR FB FB. VCC L = 2.5M HY S_I-CTRL R = 4.2 U10 VHY S = {VHY S} D2 HALF-STEP U8 I_SET = {I_SET} DIODE PPS = 100 /FA S2 /A + + - - U4 RON = {RON} S Half-Phase AND + REF 0 Step Sequence - + Generator (100 - FB. VCC pps) HY S_I-CTRL VHY S = {VHY S} D3 U7 I_SET = {I_SET} DIODE /FB S3 /B + + - - U3 RON = {RON} S AND REF + 0 - + - FB. VCC HY S_I-CTRL VHY S = {VHY S} D4 U6 I_SET = {I_SET} DIODE FB S4 B + + U2 - - RON = {RON} S AND REF + 0 - + - FB. HY S_I-CTRL VHY S = {VHY S} *Analysis directives: PARAMETERS: I_SET = {I_SET} PARAMETERS: I_SET = 0.5 VHY S = 0.1 RON = 10m .TRAN 0 80ms 0 10u SKIPBP .OPTIONS ITL4= 40 All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 16
17. 7.3 Half-Phase Sequence Drive, IPHASE=0.5A, IRIPPLE=0.1A 5.0V Clock 2.5V 0V V(CLK) 5.0V 1.0A 1 2 Phase A Current I_HYS=0.1A 2.5V 0.5A >> I_SET=0.5A 0V 0A 1 V(FA) 2 -I(U1:A) 5.0V 1.0A 1 2 Phase /A Current 2.5V 0.5A >> 0V 0A 1 V(/FA) 2 -I(U1:/A) 5.0V 1.0A 1 2 Phase B Current 2.5V 0.5A >> 0V 0A 1 V(FB) 2 -I(U1:B) 5.0V 1.0A 1 2 Phase /B Current 2.5V 0.5A SEL>> 0V 0A 0s 10ms 20ms 30ms 40ms 50ms 60ms 70ms 80ms 1 V(/FB) 2 -I(U1:/B) Time All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 17
18. 8.Drive Circuit Efficiency (%) VCC VCC VCC VCC CLK D1 Vcc R1 U9 DIODE 12 CLK 1k FA S1 A A B FA W + + 0 U5 - - RON = {RON} Acom Bcom 0 /FA S AND REF + 0 /A W /B /FB - + - U1 UNI-POLAR_STEP_MOTR FB FB. VCC L = 2.5M HY S_I-CTRL R = 4.2 U10 VHY S = {VHY S} D2 1-PHASE U8 I_SET = {I_SET} DIODE PPS = 100 /FA S2 /A + + - - U4 RON = {RON} S Half-Phase AND + REF 0 Step Sequence - + Generator (100 - FB. VCC pps) HY S_I-CTRL VHY S = {VHY S} D3 U7 I_SET = {I_SET} DIODE /FB S3 /B + + - - U3 RON = {RON} S AND REF + 0 - + - FB. VCC HY S_I-CTRL VHY S = {VHY S} D4 U6 I_SET = {I_SET} DIODE FB S4 B + + U2 - - RON = {RON} S AND REF + 0 - + - FB. HY S_I-CTRL VHY S = {VHY S} *Analysis directives: PARAMETERS: I_SET = {I_SET} PARAMETERS: I_SET = 0.5 RON = 10m .TRAN 0 40ms 0ms 10u SKIPBP VHY S = 0.1 .STEP PARAM RON LIST 10m, 100m, 1 .OPTIONS ITL4= 40 All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 18
19. 8.Drive Circuit Efficiency (%) 100 at switches Ron = 10m, (99.6%) at switches Ron = 100m, (99.3%) 98 96 at switches Ron = 1, (95.9%) 94 10ms 15ms 20ms 25ms 30ms 35ms 40ms 100* AVG(W(U1))/(-AVG(W(Vcc))) Time Note: Add trace 100*AVG(W(U1))/(-AVG(W(Vcc))) for the Efficiency. All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 19
20. Simulation Index Simulations Folder name 1. One-Phase Sequence Drive, IPHASE=0.5A, IRIPPLE=0.1A................................... 1-Phase 2. Two-Phase Sequence Drive, IPHASE=0.5A, IRIPPLE=0.1A................................... 2-Phase 3. Half-Phase Sequence Drive, IPHASE=0.5A, IRIPPLE=0.1A.................................... Half-Phase 4. Drive Circuit Efficiency (%)............................................................................... Efficiency Libraries : 1. ..¥unipolar_stp-motr.lib 2. ..¥diode.lib 3. ..¥hys_i-ctrl.lib 4. ..¥logicgate.lib 5. ..¥step-seq.lib All Rights Reserved Copyright (C) Bee Technologies Corporation 2011 20