0 1 00:00:21,450 --> 00:00:22,110 Hello. 1 2 00:00:22,200 --> 00:00:26,420 In this video we are going to learn stepper motor basics. 2 3 00:00:26,450 --> 00:00:33,770 The Stater of the stepper motor consists of electromagnet poles on which the coils are wound. 3 4 00:00:33,780 --> 00:00:36,150 You can see it in this picture. 4 5 00:00:36,150 --> 00:00:44,040 There are iron core natural magnet dislocated poles in the rotor so in the right side you can see stepper 5 6 00:00:44,040 --> 00:00:46,260 motor driver an example. 6 7 00:00:46,320 --> 00:00:54,430 And in here also you can see an example picture of stepper motor in the figure below in here. 7 8 00:00:54,480 --> 00:01:03,210 The basic principle and Operation principle of the stepper motor are described coils are wound on six 8 9 00:01:03,210 --> 00:01:12,900 pole A C B A C B but we can think it this is A this is not A this is B. 9 10 00:01:12,900 --> 00:01:18,820 This is not B this is C this is not C or inverted. 10 11 00:01:18,900 --> 00:01:26,630 We can think it like this the connection of this coils is made to form the N S pole pair mutually. 11 12 00:01:26,640 --> 00:01:32,180 There are four dislocated poles on the rotor so the rotor is here. 12 13 00:01:32,190 --> 00:01:36,150 You can see the numbers 1 and 2 and 3 and 4. 13 14 00:01:36,240 --> 00:01:47,200 So we are going to see these rotor is going to turns and Stator is not turned and 14 15 00:01:47,370 --> 00:01:54,690 there is no movement for the stator ,stator is fixed one the rotor is going to turn rotor can turn 15 16 00:01:54,690 --> 00:02:03,450 rotor can move so the next page we will see when the pair A is energized it will bring the nearest 16 17 00:02:03,600 --> 00:02:08,730 rotor dislocation pole to the same axis by pulling it to the Pole level. 17 18 00:02:09,060 --> 00:02:13,170 So what is happening when A is energized. 18 19 00:02:13,350 --> 00:02:19,130 So okay this moment this is our stator and this is our rotor position. 19 20 00:02:19,290 --> 00:02:28,110 An example after A let's energized coil B when B is energized. 20 21 00:02:28,110 --> 00:02:37,410 So this rotor goes this side you can see now the first time two rotor two position was here. 21 22 00:02:37,560 --> 00:02:49,530 Middle of the c and b and b energized or activated B pole so two is turn 30 degree to right side 22 23 00:02:50,000 --> 00:02:50,800 30 degree. 23 24 00:02:50,820 --> 00:02:51,930 How can we know it. 24 25 00:02:52,230 --> 00:02:53,270 Because . 25 26 00:02:53,340 --> 00:02:59,490 Now in the first position two was between C and B two. 26 27 00:02:59,520 --> 00:03:03,980 pole is just came from this to here. 27 28 00:03:04,110 --> 00:03:13,300 Also the same movement happened for here it was the A position from A position one turn 30 degrees 28 29 00:03:13,410 --> 00:03:22,650 to the right side and if we energized C pole what happens when the C pole is energized that moment 29 30 00:03:22,980 --> 00:03:30,240 one position turns a little bit right and it pulls to rotor two itself to C pole 30 31 00:03:30,420 --> 00:03:35,050 So one 30 degree movement happens again. 31 32 00:03:35,100 --> 00:03:42,780 So when the c coil energized after B coil the rotor pole three and one will move another 30 degrees 32 33 00:03:42,780 --> 00:03:45,480 forward to pole C this time. 33 34 00:03:45,480 --> 00:03:56,520 And if coil A energized again after coil C this time 2 and 4 rotor poles will be aligned to A pole axis. 34 35 00:03:56,520 --> 00:04:05,700 So if you noticed a and b and c coils provide sequential energy and the 30 degree motion of the rotor 35 36 00:04:05,700 --> 00:04:06,870 is provided. 36 37 00:04:07,230 --> 00:04:14,610 If this switching is continued always than 30 degree 30 degree 30 degree 30 degree and in the end 37 38 00:04:15,000 --> 00:04:26,030 after a twelve movement one turn will be existed so they will get rotational movement like this. 38 39 00:04:26,250 --> 00:04:38,040 if our switching sequence is made in reverse as C B and A so how we will turn to counterclockwise 39 40 00:04:39,100 --> 00:04:46,360 direction we will turn like this an opposite direction rotational movement will exist. 40 41 00:04:46,360 --> 00:04:53,620 The number of stator pole must always be different from the number of rotor Poles otherwise rotational 41 42 00:04:53,620 --> 00:04:58,000 movement will not start for stepper motors. 42 43 00:04:58,000 --> 00:05:07,260 Also you can see in here some examples pictures and we can get one point eight degree movement 43 44 00:05:07,270 --> 00:05:09,860 also with stepper motors. 44 45 00:05:09,910 --> 00:05:17,950 The main features of stepper motors the angle of rotation is proportional to the number of input phases 45 46 00:05:18,570 --> 00:05:19,020 phases. 46 47 00:05:19,030 --> 00:05:27,910 This is really important and also the rotation speed is proportional to the input phase ratio to phase 47 48 00:05:27,980 --> 00:05:29,110 frequency 48 49 00:05:29,140 --> 00:05:30,610 We can call it like this. 49 50 00:05:30,830 --> 00:05:38,830 Then torque can occur on their own because a permanent magnet is used for inside of the stepper motors. 50 51 00:05:38,950 --> 00:05:48,220 Stepper motors has high torque and good result and lightweight and they are working with the 51 52 00:05:48,220 --> 00:05:56,350 small angles with the high efficiency and the stepper motors are cheap and also there is no need for 52 53 00:05:56,350 --> 00:06:00,790 maintenance because it's a brushless DC motors. 53 54 00:06:00,820 --> 00:06:04,870 How many types stepper motors that we have. 54 55 00:06:04,870 --> 00:06:13,240 There are three main types of stepper motors permanent magnet hybrid synchronous and variable reluctance 55 56 00:06:13,510 --> 00:06:22,990 stepper motors and also in this picture you can see the poles X and not X Y and not Y and the Poles 56 57 00:06:22,990 --> 00:06:32,740 positions in here and in here we have our rotor and for the rotational movement we will energize X 57 58 00:06:32,750 --> 00:06:37,990 and Y and Y and X not and X not and Y not. 58 59 00:06:37,990 --> 00:06:46,720 Y not an X then we will get one turn rotational movement then if we energized continuously at our stepper 59 60 00:06:46,720 --> 00:06:48,390 motor is going to turn. 60 61 00:06:48,390 --> 00:06:56,080 Always at the stepper motor drivers at least two information must be known by the driver. 61 62 00:06:56,080 --> 00:06:58,620 This is really another important point. 62 63 00:06:58,660 --> 00:07:01,290 The first of these switching pulses. 63 64 00:07:01,300 --> 00:07:08,980 So step the switching pulses means the steps so the driver switches the motor coil sequentially in 64 65 00:07:09,340 --> 00:07:11,320 each pulse coming to it. 65 66 00:07:11,740 --> 00:07:18,220 So this information also determines the switching frequency like motor speed. 66 67 00:07:18,280 --> 00:07:25,210 Step information can be given from the plc or control unit or programming the oscillator or driver 67 68 00:07:25,210 --> 00:07:32,750 an etc. to the stepper motor driver and another information must be no. 68 69 00:07:32,890 --> 00:07:36,000 And this information is direction information. 69 70 00:07:36,310 --> 00:07:40,240 And this is digital input and it's reserved on the drive. 70 71 00:07:40,480 --> 00:07:47,050 So if this input is 1 equals 1 or high the motor will rotate one direction. 71 72 00:07:47,050 --> 00:07:55,360 And if this input is zero or low the motor is going to turn another direction during the switching of 72 73 00:07:55,360 --> 00:07:57,700 coils of the stepper motor. 73 74 00:07:57,700 --> 00:08:03,110 The reverse induction voltages will occur due to inductive property of the coils. 74 75 00:08:03,490 --> 00:08:11,560 If we are running our motor over the driver or if we are using a driver or drive for the stepper 75 76 00:08:11,560 --> 00:08:17,760 motors the manufacturer has taken the necessary measures on the driver switching floor. 76 77 00:08:18,040 --> 00:08:25,120 If however we must prevent this reverse induction voltage created by connecting our motor by plc or 77 78 00:08:25,120 --> 00:08:31,570 microprocessor control unit by connecting the free loop diode to the cause that you are going to damage 78 79 00:08:31,570 --> 00:08:34,520 the semiconductor switching elements. 79 80 00:08:34,560 --> 00:08:38,390 So in here we can see this is just steps . 80 81 00:08:38,410 --> 00:08:43,370 Then it means switching frequency at the pulses that we can think 81 82 00:08:43,450 --> 00:08:48,220 This is direction 0 or 1 in here. 82 83 00:08:48,220 --> 00:08:55,150 We need to get steps from our motor and we need to. 83 84 00:08:55,210 --> 00:08:56,820 -- 84 85 00:08:56,820 --> 00:09:03,700 We need to get a switching frequency from the plc or control unit an etc. and we need 85 86 00:09:03,700 --> 00:09:07,030 to get our direction information. 86 87 00:09:07,030 --> 00:09:12,340 These two will go inside control layer after control layer. 87 88 00:09:12,430 --> 00:09:19,600 These informations are going to go switching later than this switching layer is going to run our motor 88 89 00:09:19,880 --> 00:09:28,460 and in here you can see diode and resistor and diode and a Zener diode. 89 90 00:09:28,610 --> 00:09:34,810 Usage for the our stepper motors for to protect our stepper motors. 90 91 00:09:34,810 --> 00:09:36,340 Circuit in here. 91 92 00:09:36,360 --> 00:09:41,740 Okay we are activating transistor and in here we have a coil. 92 93 00:09:41,860 --> 00:09:42,460 Okay. 93 94 00:09:42,460 --> 00:09:54,100 And that moment we need to prevent our stepper motor circuit from reverse induction 94 95 00:09:54,220 --> 00:09:55,210 voltage. 95 96 00:09:55,210 --> 00:09:58,490 And if stepper motors types are not known. 96 97 00:09:58,540 --> 00:10:01,420 This is really another one important point. 97 98 00:10:01,570 --> 00:10:04,170 Connection type must be found first. 98 99 00:10:04,180 --> 00:10:12,160 So if there are four cables coming out from the motor our stepper motor So this indicates that our motor 99 100 00:10:12,160 --> 00:10:13,790 is bipolar. 100 101 00:10:13,930 --> 00:10:19,810 There are four coils in stepper motors one cable is removed from each coil. 101 102 00:10:19,810 --> 00:10:24,310 There are five cables and one of which is common. 102 103 00:10:24,310 --> 00:10:27,680 So there are four cables for the run. 103 104 00:10:27,680 --> 00:10:36,990 Our stepper motor and one cable comes and that cables is our common cable and there is a constant resistance. 104 105 00:10:37,120 --> 00:10:43,450 Really important point is here the constant resistance value between the coomon Cable and the other 105 106 00:10:43,450 --> 00:10:51,130 four cables in our measurement with ohmmeter so if we measure with our multimeter or ohmmeter between 106 107 00:10:51,130 --> 00:11:01,150 the cables one cable must be a constant resistance value with anothers so we can find common cable 107 108 00:11:01,390 --> 00:11:03,040 like this method. 108 109 00:11:03,040 --> 00:11:10,210 The motors operating voltages applied to this cable which cable to the common cable we connect the ends 109 110 00:11:10,210 --> 00:11:17,110 of switching elements such as transistors or FET to the remaining four cables so 110 111 00:11:17,170 --> 00:11:27,480 We will just give pulses our direction and also our pulses switching frequencies to these four cables. 111 112 00:11:27,520 --> 00:11:35,080 If our connection is correct the motor starts rotating if it is wrong the motor doesn't turn and the 112 113 00:11:35,080 --> 00:11:36,710 motor is going to vibrate. 113 114 00:11:36,760 --> 00:11:41,100 In this case we need to change some of the four wires. 114 115 00:11:41,110 --> 00:11:48,010 This process continues until the correct cables are found and the motor turns and there are 16 combinations 115 116 00:11:48,010 --> 00:11:58,360 of four cables and we find the correct cables after a maximum of 16 trials in here you can see unipolar 116 117 00:11:58,900 --> 00:12:06,850 motor and bipolar motor tables and the steps and which steps which cables are + which cables are 117 118 00:12:07,060 --> 00:12:13,580 - the applied voltages and applied for switching frequencies to these cables. 118 119 00:12:13,720 --> 00:12:21,010 In this table you can see for example total step number four one revolution. 119 120 00:12:21,070 --> 00:12:31,960 If we have a 24 step for one revolution so our step angle is 15 multiply this , it will equal to always 120 121 00:12:32,220 --> 00:12:34,210 360 121 122 00:12:34,240 --> 00:12:39,220 So this is one cycle and one turn degree. 122 123 00:12:39,220 --> 00:12:42,790 So in here for example we have one hundred. 123 124 00:12:42,790 --> 00:12:49,820 Step number four one revolution our step angle will be 3.6 124 125 00:12:50,170 --> 00:12:52,550 And if we have four hundred. 125 126 00:12:52,570 --> 00:12:59,370 Step number four one revolution or step angle is going to be zero point nine degrees. 126 127 00:12:59,710 --> 00:13:07,360 And if our stepper motor has six wires it means that the 4 coils available are divided into 127 128 00:13:07,360 --> 00:13:14,170 two groups and the common cable is separated from them so we can say there are two groups as three wire 128 129 00:13:14,530 --> 00:13:17,240 and two coil cable and one common cable. 129 130 00:13:17,380 --> 00:13:20,930 And there is no electrical connection between them. 130 131 00:13:21,070 --> 00:13:25,090 It is quite easy to distinguish between multimeter and this three group. 131 132 00:13:25,750 --> 00:13:33,430 So in these separated groups the cable with the constant resistance with the common cable like four 132 133 00:13:33,430 --> 00:13:41,860 cable and I mean four plus one common cable five wire stepper motors and it's also similar like six 133 134 00:13:41,860 --> 00:13:49,030 wires we need to find a common cable as a result after compared cables resistance common cables can 134 135 00:13:49,030 --> 00:13:58,300 be found easily then it looks like five wire stepper motor the work to be done next is the same as four 135 136 00:13:58,540 --> 00:14:07,210 five wires the motor shaft must never be turned during the measurement of the measuring instrument resistance 136 137 00:14:07,210 --> 00:14:13,930 to be produced at the poles can cause inaccurate measurements for example the wormscrew connected to 137 138 00:14:13,930 --> 00:14:20,290 stepper motor and it moves to table and work piece back and forth during this movement the milling 138 139 00:14:20,290 --> 00:14:23,920 cutter removes sawdust from the workpiece. 139 140 00:14:23,920 --> 00:14:33,070 So in here we will do some calculations the step of the wormscrew is 2 mm and the stepper motor performs 140 141 00:14:33,340 --> 00:14:43,430 one point eight degree steps let's take these values and let's find some detail information so it 141 142 00:14:43,430 --> 00:14:50,150 takes two hundred steps in one turn because one point eight degree multiply by two hundred. 142 143 00:14:50,150 --> 00:14:59,750 So we have one turn so two hundred sixty degree multi divided by one 1.8 a degree we 143 144 00:14:59,750 --> 00:15:02,520 will get two hundred and steps in one turn. 144 145 00:15:02,690 --> 00:15:11,930 The amount of feed per step is to two millimeters here two divided by two hundred step and we will get 145 146 00:15:12,200 --> 00:15:21,950 zero point zero one millimeter per step the motor must perform ten divided by zero point zero 146 147 00:15:21,950 --> 00:15:32,700 one and one thousand steps for one centimeter we found it now as a centimeter . 147 148 00:15:32,880 --> 00:15:33,490 -- 148 149 00:15:33,520 --> 00:15:35,770 How motor must performing ? 149 150 00:15:35,770 --> 00:15:39,340 And for one centimeter motor turns. 150 151 00:15:39,360 --> 00:15:41,600 One thousand steps. 151 152 00:15:41,630 --> 00:15:43,810 Four long metal removal. 152 153 00:15:43,810 --> 00:15:49,960 So stepper motor will take one thousand steps and the stop for one centimeter. 153 154 00:15:49,960 --> 00:15:57,610 Whether the part is soft or hard the system should be prompt to move at speed of zero point zero two 154 155 00:15:57,640 --> 00:15:59,620 millimeter per second. 155 156 00:15:59,620 --> 00:16:03,050 In this case zero point zero two divided. 156 157 00:16:03,130 --> 00:16:09,880 Zero point zero one so two degree motor must turn two steps per second. 157 158 00:16:10,000 --> 00:16:19,720 So the switching frequency will be for one cm we get this value 1000 divided by 2 ,500 millisecond. 158 159 00:16:19,900 --> 00:16:28,090 Will be our switching frequency the bench will take 1 cm pet in five hundred seconds. 159 160 00:16:28,090 --> 00:16:28,770 Why. 160 161 00:16:28,820 --> 00:16:31,610 Because 500 milliseconds. 161 162 00:16:31,900 --> 00:16:34,260 Multiply by 1000. 162 163 00:16:34,290 --> 00:16:34,970 This value 163 164 00:16:35,300 --> 00:16:41,710 So this value result to the multiplication result is five hundred seconds. 164 165 00:16:41,830 --> 00:16:45,090 One cm equals 1000 step. 165 166 00:16:45,130 --> 00:16:51,170 Multiply by 500 ms and we got this value at the end of this process. 166 167 00:16:51,280 --> 00:16:57,400 The milling knife will be removed from the piece and the must reach to starting point of the machine. 167 168 00:16:57,400 --> 00:16:59,280 This is really important. 168 169 00:16:59,320 --> 00:17:00,920 1 goes forward. 169 170 00:17:01,180 --> 00:17:06,680 It needs to come backward and to prevent loss of time in return. 170 171 00:17:06,790 --> 00:17:15,750 It may be requested to run at two hundred steps per second we can calculate our stepper motor 171 172 00:17:15,750 --> 00:17:24,210 details and the steps and the switching frequency and the distances we'd like this and we have in here 172 173 00:17:24,450 --> 00:17:28,170 the driving methods of stepper motors. 173 174 00:17:28,170 --> 00:17:35,760 First of all first option stepper motor one phase driving method only one of the motor 174 175 00:17:35,760 --> 00:17:45,550 windings is excited called single phase excitation the stimulation should be 1 0 0 0 0 1 0. 175 176 00:17:45,690 --> 00:17:52,290 Attention this just one windings are one the rest of all is zero. 176 177 00:17:52,320 --> 00:17:58,820 So 1 0 0 0 the next 1 0 1 0 0 0 0 1 0. 177 178 00:17:58,950 --> 00:18:02,340 And like this it is clockwise direction. 178 179 00:18:02,340 --> 00:18:13,150 If we start from the last winding to first winding like this from right to left 0 0 0 1 0 0 1 0 an 179 180 00:18:13,150 --> 00:18:18,900 etc.. the counterclockwise rotation is going to be exist. 180 181 00:18:19,050 --> 00:18:25,890 And with this method we can better understand the working principle of stepper motors and this method 181 182 00:18:25,890 --> 00:18:33,300 is not used much since the torque and stopping characteristics of stepper motors are not good , two 182 183 00:18:33,420 --> 00:18:38,230 Second option driving the stepper motor in two phases. 183 184 00:18:38,310 --> 00:18:45,690 It is called the form extension in which two of the motor windings are simultaneously stimulated in sequence 184 185 00:18:46,020 --> 00:18:52,720 in two fast excitation the transient response of rotor is faster than the single fast excitation. 185 186 00:18:52,860 --> 00:18:57,390 But the power drawn from the power supply has doubled here. 186 187 00:18:57,720 --> 00:19:06,180 So this method is used generally because it's a torque really high and the stopping characteristics 187 188 00:19:06,240 --> 00:19:11,370 are really good for stepper motors in two phases. 188 189 00:19:11,670 --> 00:19:17,120 So third option driving of stepper motors in one and two phases. 189 190 00:19:17,430 --> 00:19:20,150 It's like a half angel rotation method. 190 191 00:19:20,280 --> 00:19:29,100 In this extension mode single phase and two phases are applied consecutively 191 192 00:19:29,340 --> 00:19:34,730 so single phase and two phase are applied together here. 192 193 00:19:34,770 --> 00:19:43,760 The rotor makes a half step really important another point rotor makes a half step move for each excitation 193 194 00:19:43,830 --> 00:19:44,570 signal. 194 195 00:19:44,640 --> 00:19:51,630 Because of this stimulation mode we reduce the step angle of a motor that is 2 degrees from the factory 195 196 00:19:51,900 --> 00:19:54,360 for example to 1 degree. 196 197 00:19:54,360 --> 00:20:02,390 So if we need to run very small degrees and etc. we can run our stepper motors. 197 198 00:20:02,430 --> 00:20:09,690 The third option as third option one and two phase altogether and for this video. 198 199 00:20:09,900 --> 00:20:10,890 I'm finished. 199 200 00:20:10,890 --> 00:20:12,800 See you in the next video.