Hum starts only when motor is turned ON and increases when I move my arm closer to the spindle (with is minimum distance to the motor). Thank you for tips. I'll try to add Mu Metal and to cover internal walls of my motor case. Have some 0.2 mm Permalloy sheet to cut. Lets see then....
Done. It is dead quite now with Mu Metal installed onside of motor base. Thank you Pyramid for all tips.
Hi carlthess40,
I got one already. Thank you for checking.
I hope I can reduce frequency in order to get BLWR to run 300RPM for 33.3 speed. My pulley is turning sub-platter, kind of same as Rega and many other TTs are constructed.
I’m I right?
Alex
I found needed answers in this thread, but I have final voltage imbalance between phases, same as indicated by someone here on thread.
I have little differences in voltages on 3 sinuses after null sum of all 3. TP1 vs. GND set to 20mV as min. I assume it is expected some deltas there since we set 3 VRs to get identical voltage on 3 phases first and then we tweaked same VRs to set balance and to null the sum.
Is this correct statement?
I have little differences in voltages on 3 sinuses after null sum of all 3. TP1 vs. GND set to 20mV as min. I assume it is expected some deltas there since we set 3 VRs to get identical voltage on 3 phases first and then we tweaked same VRs to set balance and to null the sum.
Is this correct statement?
Thank you for clarification. How about 0.1 VAC RMS differences between phases in final step? Is it critical? I do see some guys claimed about same aspect here.
I don't understand your question. Where does it say to adjust for 0.1VRMS difference between phases?
My bad explanation style...
I say that I have about 100mV RMS difference between 0/120/240 deg phases at the end of my setup process. As an example: 0 has 4.1V, 120 has 4.2 and 240 has 4.3V.
I say that I have about 100mV RMS difference between 0/120/240 deg phases at the end of my setup process. As an example: 0 has 4.1V, 120 has 4.2 and 240 has 4.3V.
OK, I understand. You have that much difference between phases when TP1 is minimum? That seems unlikely; are you measuring from each phase to ground?
At any rate, it is not super critical.
At any rate, it is not super critical.
I see. Thank you.
You have that much difference between phases when TP1 is minimum?
A: Yes, it is. These differences are when TP1 voltage is set to its min.
Are you measuring from each phase to ground?
A: Yes. Is any other way to measure each phase voltage?
I see we have two GND passes from SG4 to MA-3D. One is via power connector and second is coming from 0/120/240/GND wiring. Is it not a possibility for GND loop?
Also, does it make sense to Earth our GND here or you would like to run it floated?
You have that much difference between phases when TP1 is minimum?
A: Yes, it is. These differences are when TP1 voltage is set to its min.
Are you measuring from each phase to ground?
A: Yes. Is any other way to measure each phase voltage?
I see we have two GND passes from SG4 to MA-3D. One is via power connector and second is coming from 0/120/240/GND wiring. Is it not a possibility for GND loop?
Also, does it make sense to Earth our GND here or you would like to run it floated?
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Connecting the supply ground to earth is never a bad idea, unless it introduces a hum. At these low voltages, a safety ground is not mandatory.
The extra ground connections should not create a difference in potential; at the low gain of the amp, even if they did, they would be insignificant. If you want, you can eliminate one.
The extra ground connections should not create a difference in potential; at the low gain of the amp, even if they did, they would be insignificant. If you want, you can eliminate one.
I see. Thank you for all tips. My motor is on its way. So, hope to run full setup in several days.
Got my motor connected today. Dilemma is about speed. Since I’m moving sub-platter (about 160mm), my pulley for 600RPM motor should be close to 0.9mm. It is too small to make good belt grip even with two belts to be used. What is the bad side of 300RPM to use with our BLWR? 300RPM will solve all my issues with pulley.
Another thing is related to motor temperature. I tested it with 20Hz and waited about 25 min. It is no vibration, but motor is quite hot. Is it normal?
BLWR motor PSU - YouTube
Last inquiry: I see some guys (on this forum) talk about DC when other about AC for motor supply (not about PSU). So, manual asks about P2P or RMS, and then I use AC measurements only. Is it correct?
Another thing is related to motor temperature. I tested it with 20Hz and waited about 25 min. It is no vibration, but motor is quite hot. Is it normal?
BLWR motor PSU - YouTube
Last inquiry: I see some guys (on this forum) talk about DC when other about AC for motor supply (not about PSU). So, manual asks about P2P or RMS, and then I use AC measurements only. Is it correct?
Last first: If you are looking at the output to the motor, then AC measurement is correct. Supply voltage will be with DC. You may also want to ensure the DC voltage at the output to the motor is ~VCC/2 on each output.
Temp: 45°C = ~113°F. This is normal and is not hot. The motors are rated to 80°C. It will run cooler with a metal case. One of the reasons these motors feel warmer, the stator coils are mounted on the case so the heat conduction is much better than most AC synch motors; they dissipate heat better than the Hurst motors so they feel warmer. Hurst rate their motors at 30°C temp increase during operation, so the coils operate at ~52°C (126°F).
Something is not right with your numbers. The BLWR motor will run at 300 RPM with 20Hz, not 600 RPM. For 33.333 RPM the subplatter-pulley ratio should be 9:1, so 160:17.778mm not 9mm. 17.778 mm is ~0.7" and should work with round or flat belts.
Temp: 45°C = ~113°F. This is normal and is not hot. The motors are rated to 80°C. It will run cooler with a metal case. One of the reasons these motors feel warmer, the stator coils are mounted on the case so the heat conduction is much better than most AC synch motors; they dissipate heat better than the Hurst motors so they feel warmer. Hurst rate their motors at 30°C temp increase during operation, so the coils operate at ~52°C (126°F).
Something is not right with your numbers. The BLWR motor will run at 300 RPM with 20Hz, not 600 RPM. For 33.333 RPM the subplatter-pulley ratio should be 9:1, so 160:17.778mm not 9mm. 17.778 mm is ~0.7" and should work with round or flat belts.
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Thank you a lot for all these important details.
"DC in output to the motor is ~VCC/2 on each output": it is due to 50% duty cycle and I can see that on scope soon.
I feel relief about motor temperature and its case design will be done tomorrow.
I must copy external dimensions of my existing one from my turntable. I’ll upload drawing when it will be ready. It might help to someone who is upgrading same Wilson Benesch Circle One with BLRW.
Yes, and 20Hz is for 300RPM when 40Hz is for 600RPM. My question was related to benefits and disadvantages of these two settings. 300RPM is easier for my setup due to larger pulley dia. 600RPM is doable too, but pulley will be 8.889mm vs. 17.778mm for 300RPM. As I mentioned, 300RPM pulley will use a better grip, however I would like to hear your opinion about 600 vs. 300RPM preferences.
"DC in output to the motor is ~VCC/2 on each output": it is due to 50% duty cycle and I can see that on scope soon.
I feel relief about motor temperature and its case design will be done tomorrow.
I must copy external dimensions of my existing one from my turntable. I’ll upload drawing when it will be ready. It might help to someone who is upgrading same Wilson Benesch Circle One with BLRW.
Yes, and 20Hz is for 300RPM when 40Hz is for 600RPM. My question was related to benefits and disadvantages of these two settings. 300RPM is easier for my setup due to larger pulley dia. 600RPM is doable too, but pulley will be 8.889mm vs. 17.778mm for 300RPM. As I mentioned, 300RPM pulley will use a better grip, however I would like to hear your opinion about 600 vs. 300RPM preferences.
300 RPM is OK with the BLWR series because the sinewave is still 20Hz. The BLWS series uses 20Hz for 600 RPM with no problem. 300 RPM on the BLWS is 10Hz, and while it will work, I believe the BLWS motors run better at 600 RPM.
Excellent news for me. Thanks. Since I have BLWR motor, then I stick to 20Hz for 300RPM.
Last inquiry is about IC heatsinks. Is any P/N that is specially matches your PCB design? I might miss it in BOM.
Last inquiry is about IC heatsinks. Is any P/N that is specially matches your PCB design? I might miss it in BOM.