HY DIV268N 5A Stepper Driver

HY-DIV268N-5A Stepper DriverThese are my engineering notes when evaluating the HY-DIV268N-5A stepper driver. The performance of the driver was not what was expected. Therefore I did some reverse engineering and modifications to see if I could rectify the situation. The bottom line is that this stepper driver is a bit of junk. But with some persistency and work it is possible to make it work correctly. The HY-DIV268N-5A can be seen in figure 1. The driver is based on the TB6600HG IC from Toshiba. See reference 1. The device can be purchased from eBay and Amazon among other sources. Figure 1, HY-DIV268N-5A device The problem I had with the driver was missing/added pulses. The motor was also very noisy. The stepper motor did not position itself on the correct position. For example if I did rotate the motor X number of steps CW and then X number of steps CCW I expected the stepper motor shaft to be in the same position. That was not the case. If I repeated the movement X steps CW and X steps CCW a number of times I could note how the position did varied. Sometimes the offset was positive and sometimes the offset was negative. The conclusion was that steps was added or subtracted in a more or less random way. I was using micro stepping with a factor 16 to get smooth movements. The stepper motor used need 200 pulses per revolution, so with micro stepping this becomes 3200 pulse/revolution. The pulse input train to the stepper driver was first examined. No missing steps, more or less perfect timing and smooth start and stop. After some measurements I could conclude that the stepper motor had made up to +/- 180 steps wrong during the repeated movement for about 150 times. Therefore I looked into the stepper driver and disassembled it and found the picture to the right in figure 1. The first thing I did was to make a check of the +5 Volt internal power supply provided by the SM6FIE, Bo Gärdmark, Gothenburg Sweden Email: [email protected], web: www.spectron.us/SM6FIE Copyright 2009, all rights reserved, Read the EULA and safety warnings on web site HY-DIV268N-5A Stepper Driver.docx, 2009-03-08 17:33, page: 1 (12) TB6600HG. I did measure the on pin 8 of the 6N137 opto coupler for the step circuit (the lower one in figure 1, right). The power supply line for the opto coupler look like picture in figure 2. This is more or less a disaster. This was measured without any connection to the optocouplers, just the motors and the supply was connected. I tested a number of different 24 Volts power supply’s but the problem persisted. Figure 2, voltage spikes on 5 volt power supply All the time I used a 24 Volt external power supply for the device with sufficient current capacity. One I used could deliver up to 60 Amps at 24 volt. Note that the frequency of the spikes are 41.9 KHz, this is the same as the IC chopper frequency. I modified the circuit board and bypassed the power supply with 0.1 uF capacitors at strategic points. Then I redid the measurement above and got this picture, se figure 3. Figure 3, spikes after modification SM6FIE, Bo Gärdmark, Gothenburg Sweden Email: [email protected], web: www.spectron.us/SM6FIE Copyright 2009, all rights reserved, Read the EULA and safety warnings on web site HY-DIV268N-5A Stepper Driver.docx, 2009-03-08 17:33, page: 2 (12) The yellow trace is the 5 volt power supply and the blue line is the output from the “Step” opto coupler collector output. This is clearly much better but far from perfect. The next thing I suspected was that there was ripple on the Vref signal. A check with the oscilloscope gave the picture as in figure 4. Figure 4, Vref pin signal The voltage level, 1.94 volt is according to the datasheet for TB6600HG (0.3V ≤ Vref ≤ 1.95V). But the spikes shouldn’t be there. The Vref circuit looks like this, see figure 5: Figure 5, modified Vref circuit I added C5 and C6 to filter the reference voltage. I have also changed R11, R12, R13 and R14 so that the possible span of the Vref will be within the limits stated in the datasheet (0.3V ≤ Vref ≤ 1.95V). SM6FIE, Bo Gärdmark, Gothenburg Sweden Email: [email protected], web: www.spectron.us/SM6FIE Copyright 2009, all rights reserved, Read the EULA and safety warnings on web site HY-DIV268N-5A Stepper Driver.docx, 2009-03-08 17:33, page: 3 (12) After this and checking the Vref voltage again with the oscilloscope I got the waveform as in figure 6. This is clearly an improvement. Figure 6, Vref after adding C5 and C6 I had the suspicion that the Vref have a limit current capability. Therefore I moved the supply of the LED2 to the 24 volt supply with an additional resistor of 8.1 K (R32). I also removed D1 from to be in series with the 24 volt supply line to be connected with the anode to ground and cathode to the +24 volt supply line. I also added 0.1 uF ceramic capacitors to the 24 volt line (C20, C21, C22) see figure 7. Figure 7, modification of the supply The above modifications had a profound influence on the Vreg and 24 volt supply ripple. Finally I changed the supply of the LED’s (Power, Step). The LED’s where supplied by the Vreg +5 Volts. However, on good grounds you can suspect that the Vref has a very limited current capacity. Therefore I moved the LED’s to be supplied by the 24 Volt supply instead. To do this I had to add some resistors to limit the current. I found it easier to add resistors instead of changing the original ones. SM6FIE, Bo Gärdmark, Gothenburg Sweden Email: [email protected], web: www.spectron.us/SM6FIE Copyright 2009, all rights reserved, Read the EULA and safety warnings on web site HY-DIV268N-5A Stepper Driver.docx, 2009-03-08 17:33, page: 4 (12) Current Switch Settings Switch settings label are wrong on the protection cover. The correct settings for S4/S5/S6 (step size) are as in figure 8. This manufacturing error is remarkable. S6 On On On On Off Off Off Off S5 On On Off Off On On Off Off S4 On Off On Off On Off On Off Standby 1/1 1/2A 1/2B 1/4 1/8 1/16 Standby Figure 8, S4/S5/S6 settings Changes made (modifications) Below is a summation of the changes that I made to the circuit. See the schematics in appendix. The schematics shall reflect the changes I made. I have tried to keep the same identifications for resistor, capacitors etc. as in the schematics that can be found on the net, see appendix (links). Figure 9, modifications, Top view Referring to figure 9 (top view of the PCB) I made the following modifications: T1. Added decoupling capacitors to Vref C5, C6 T2. Changed LED2 to be supplied by +24 volt, added R32 SM6FIE, Bo Gärdmark, Gothenburg Sweden Email: [email protected], web: www.spectron.us/SM6FIE Copyright 2009, all rights reserved, Read the EULA and safety warnings on web site HY-DIV268N-5A Stepper Driver.docx, 2009-03-08 17:33, page: 5 (12) T3. Added decoupling capacitor to +24V, C20 T4. Changed R23 to 15K T5. Changed D1 to be between ground and +24 Volt and placed a jumper between J3/1 and trace to Vcc-A and Vcc-B. T6. Ground test point for measurements T7. Test points for 6N137 Figure 10, modifications, bottom view Referring to figure 10 (bottom view of the PCB) I made the following modifications: B1. B2. B3. B4. B5. B6. B7. B8. B9. B10. B11. Added Decoupling capacitor C21 Added Decoupling capacitor C4 Added Decoupling capacitor C23 Added Decoupling capacitor C24 Added Decoupling capacitor C25 Replace resistor with 330 ohms Added Decoupling capacitor C22 Replace resistors R24, R25, R26 and R27 Added Decoupling capacitor C20 Made a “heavy” ground connection Added Decoupling capacitor C20 SM6FIE, Bo Gärdmark, Gothenburg Sweden Email: [email protected], web: www.spectron.us/SM6FIE Copyright 2009, all rights reserved, Read the EULA and safety warnings on web site HY-DIV268N-5A Stepper Driver.docx, 2009-03-08 17:33, page: 6 (12) Summarize of changes: 1. Changed D1 to be not in series with power +24 Volts. Instead D1 is connected with cathode to +24 V and anode to ground. 2. Added C20, C21, C22 to +24 volt supply 3. Added C23, C24, C25, C26 to Vreg supply 4. Changed R3, R4, R5 to 330 ohm (was 51 ohms!), Important!! 5. Modified Vref circuit to be according to datasheet. R23 = 15K, R25 = 2.2K, R26=1.5K and R27=1K 6. Changed LED1 (Step indicator) to be supplied by 24 Volt. Added R26=12K 7. Changed LED2 (Power) to be supplied by 24 Volt, added R31 8. I didn’t do this but changing R7 and R8 to 2.2 K is a good idea to increase noise immunity. 9. Ground all system devices (motion controller, power supplies, driver etc.) in a star fashion (common point). Test of modification I did some measurements before and after the modifications. The test setup for the Y-axis is shown in figure 9. The stepper motor moves the Y-Axis sleigh between the A and B position. At the start the Y-axis is set to the A position, see figure 10. The indicator clock is set to zero at this position. A G code macro program is executed. The macro program moves the sleigh to the B position and waits there for one second. Thereafter the sleigh is moved back to position A. When it has stopped at position A the macro program sends a signal to the PIC32MX microcomputer to obtain the value of the indicator clock. Due the fact that the same distance is moved in the negative Y-direction as in the positive Y-direction the indicator clock should be zero. Figure 9, test setup If the stepper has jammed, pulses to the stepper has been missed etc. the value of the indicator clock will not be zero. That is to say that we have an offset error. The sequence above is repeated and each time the Indicator clock value is collected. Furthermore, the number of stepper pulses is counted by the PIC32MX as well as the timing for each pulse. The max and minimum periods for the pulse train is saved. This information is transferred via USB to the PC#1 and saved to a database for analyze. SM6FIE, Bo Gärdmark, Gothenburg Sweden Email: [email protected], web: www.spectron.us/SM6FIE Copyright 2009, all rights reserved, Read the EULA and safety warnings on web site HY-DIV268N-5A Stepper Driver.docx, 2009-03-08 17:33, page: 7 (12) Figure 10, Y-axis test movements Two tests were done. One test was done before modifications and one after the modifications. The result can be seen in figure 11. The ripple in the graph for the modification is maximum 4 microns (4E-6 meters). The setup is very sensitive to temperature, vibrations etc. So in reality the result after the modifications is almost a straight line, which is to say nearly prefect. The feedrate was as I remember 750 mm/minute during the test. Test before and after Modifications Error (Micron) 120 100 80 60 40 No Mod 20 With Mod 0 -20 -40 Test # -60 0 50 100 150 200 Figure 11, tests before and after modifications Stress Test I decided to do a stress test and see how far I could go when setting feedrate and feed acceleration. I must admit that I got figures so high that I didn’t care to go further. The final feedrate I tested was at SM6FIE, Bo Gärdmark, Gothenburg Sweden Email: [email protected], web: www.spectron.us/SM6FIE Copyright 2009, all rights reserved, Read the EULA and safety warnings on web site HY-DIV268N-5A Stepper Driver.docx, 2009-03-08 17:33, page: 8 (12) 4000 mm/min with an acceleration of 110 mm/s2, this without any significant errors. I’m impressed by this. See figure 12. Note that the stepper pulses are about 10 uS in this case (with feedrate 4000 mm/min). So we have a frequency of about 100 KHz. The eCut motion controller is specified up to 200 KHz. However the TB6600HG IC, the brain in the stepper driver has a minimum pulse length of about 5 uS. SO we are approaching the specification limits. The ripple of +/- 2 micron around the zero line is probably due to measurement errors induced by the sensor, temperature, vibration in the room when I am moving around etc. Remember 1 micron is a very short distance. You have to have one million microns to get one meter. Stress Test, eCut FR4000 Error Microns 20 15 10 5 0 -5 -10 -15 Test # -20 0 100 200 300 400 500 600 Figure 12, Stress test I made a video that I uploaded to YouTube that shows the measurement of the above graph. The link is: http://youtu.be/65_4ZUPfGNU In the video you can get a feeling how fast the Y-axis is moving as well as the acceleration of the axis. I did time how long it took to travel 30 mm, including acceleration and deceleration. I got the time to be more or less exactly one second. Regards /BG SM6FIE, Bo Gärdmark, Gothenburg Sweden Email: [email protected], web: www.spectron.us/SM6FIE Copyright 2009, all rights reserved, Read the EULA and safety warnings on web site HY-DIV268N-5A Stepper Driver.docx, 2009-03-08 17:33, page: 9 (12) Document version: 1.1 Date: 2015-04-08 16:43 Document name: HY-DIV268N-5A Stepper Driver.docx 6147 5464 2015-04-06 19:30 Create: 2015-04-03 01:48 Bo Gärdmark SM6FIE, Bo Gärdmark, Gothenburg Sweden Email: [email protected], web: www.spectron.us/SM6FIE Copyright 2009, all rights reserved, Read the EULA and safety warnings on web site HY-DIV268N-5A Stepper Driver.docx, 2009-03-08 17:33, page: 10 (12) Appendix Good Links: TB6600HG datasheet: http://download.siliconexpert.com/pdfs/2012/7/3/0/23/22/201/tos_/manual/tb6600hg_summary_ en_20120119.pdf Thread: Haoyu TB6600: http://www.cnc-arena.com/en/forum/haoyu-tb6600--187150.html Thread: TB6600 drive from EBAY, this is a very good discussion about the TB6600. I’m thankful for the input I got from reading this thread. http://www.cnczone.com/forums/stepper-motors-drives/186930-tb6600-drive-ebay-15.html Schematics Haoyu TB6600: http://www.cnczone.com/forums/attachment.php?attachmentid=190090&d=1372455055 LeadShine, good Stepper Drivers: http://www.leadshine.com/productdetail.aspx?type=products&category=stepperproducts&producttype=stepper-drives&series=DM&model=DM556 Video, Stress Test of HY-DIV268N-5A Stepper Driver: http://youtu.be/65_4ZUPfGNU Schematics of HY-DIV268N-5A Stepper Driver: See last page in this document! SM6FIE, Bo Gärdmark, Gothenburg Sweden Email: [email protected], web: www.spectron.us/SM6FIE Copyright 2009, all rights reserved, Read the EULA and safety warnings on web site HY-DIV268N-5A Stepper Driver.docx, 2009-03-08 17:33, page: 11 (12) B C D E F G H Vreg 0.1u 0.1u R14 C3 2K 4 8.1K 4.7K +24V J3 1 2 SW4 M3 SW6 SW5 M2 C5 C6 0.1u 1u D1 0.01u C22 0.1u C21 FR307 D5 FR307 D2 R25 R26 4.7K 2.2K 1.5K SW1 SW2 SW3 R27 1K R31 2K R30 10K 0.1u 0.1u R24 2K C6 4700u 47K M1 R22 330K R21 330K R20 330K R30 10K Q3 R29 0.1u D4 TB6600HG R13 Vreg C7 C20 Vreg Vcc A Vcc B 11 FR307 Osc Stepper A/B 15 D3 R17 10K NFB Vref 10 5 6N137 NFA 12 FR307 6 23 Out 2B M1 M2 M3 1 2 3 4 FR307 3 0.1u Out 1B J1 14 R1 0.22 7 330 5 Out 2A TQ Reset Latch Power (24V) 16 13 Direction 2 C8 R19 10K 8 U2 7 8 9 Vreg Q3 R18 10K 6N137 5 CONN-SIL6 U4 R2 0.22 3 19 4 A-Gnd 6 Out 1A 17 3 Step Dir Enable S-Gnd 21 22 18 7 2 8 U1 Step 2 24 20 6 15K B-Gnd R28 15K Mon Alert 0.1u R23 25 1 4.7K 330 Step 0.1u Q1 R9 Vreg E Step C5 J2 Q4 100u C1 3 K PC817 R5 R32 10K 2 R4 C4 R25 10u 330 1 2 3 4 5 6 C2 10K R15 C +24V 0.01u Step Enable A Power R29 C26 4.7K C25 R8 4.7K C24 R7 2K C23 0.1u U3 1 R6 12K LED1 K LED2 Vreg R26 R3 J FILE NAME: Hy-DIV268N-5A Stepper Driver.pdsprj DESIGN TITLE: Hy-DIV268N-5A Stepper Driver.pdsprj @AUTHOR SM6FIE BY: PATH: D:\Mina Dokument\Projekt\Electronics Designs\CAD-CAM\CNC3020\Stepper DATE: 2015-04-07 TIME: 19:22:31 PAGE: 1 of 1 REV:@REV and ctrl replace\Documentation\HY-DIV268N-5A Reverese Engineering\Hy-DIV268N-5A Steppe