I had flipped one of the tantalums during initial installation (c11) but I fixed that before powering up. I think when I did that I must have broke on of the leads or something so I've order some more of those. Everything else looks good on the board, all the others are correctly oriented and I just reflowed every joint on the board. Is there anything else I can for right now with out turning on the board since c11 is missing?
I see no advantage to using 300 RPM and several disadvantages:
Hurst Motors: 300 RPM vs 600 RPM--Upgrade or Myth?
I should have mentioned that you will need to reduce the output voltage at the lower speed, otherwise the motor will draw more than 12W (if you set it for the same voltage as 600 RPM).
Hurst Motors: 300 RPM vs 600 RPM--Upgrade or Myth?
I should have mentioned that you will need to reduce the output voltage at the lower speed, otherwise the motor will draw more than 12W (if you set it for the same voltage as 600 RPM).
I got the caps today, that didn't fix the problem. all three of the channels are still outputting 15.4V. Coming into the inductors its 14.2V. Are my inductors not soldered on correctly? When the SA-4 is turned on I am getting 7.5V DC at the output but its jumping back and forth from 7.3-7.5V
Cheers and Thanks to rsritchey for the help!
The people on here never cease to amaze me with there willingness to share and provide.
Hats off to you guys
@Pyramid, while doing some more calculations, I was hoping you may be able to confirm something given your wealth of experience with these motors.
I am to use the BLWR172 motor, and was hoping to try rim drive. My platter has a diameter of 320mm, and I aim for a pulley of a diameter of 40mm (including the periphery of the o-ring that touches the platter).
In my calculations, that equates to a 1:8 idler/platter ratio, which means the motor would have to run at ~267rpm for 33 1/3 at the platter, and 360rpm for 45 at the platter.
Is that correct?
And if so, would you say the BLWR would not have issues running that low?
Decreasing the idler diameter to say, 30mm, would mean that the motor would run at 355rpm for 33 1/3.
I am to use the BLWR172 motor, and was hoping to try rim drive. My platter has a diameter of 320mm, and I aim for a pulley of a diameter of 40mm (including the periphery of the o-ring that touches the platter).
In my calculations, that equates to a 1:8 idler/platter ratio, which means the motor would have to run at ~267rpm for 33 1/3 at the platter, and 360rpm for 45 at the platter.
Is that correct?
And if so, would you say the BLWR would not have issues running that low?
Decreasing the idler diameter to say, 30mm, would mean that the motor would run at 355rpm for 33 1/3.
@Pyramid, additionally:
I have been trying to find alternatives to the Anaheim motors, mostly because they seem to take too long to get in stock, as well as due to the prohibitive shipping ($150 to Europe - which seems much).
While I understand that the amp was made to support specifically the two Anaheim motors, can you spare some time and look into this option:
http://www.zhengkemotor.com/upload/file/20140109_164856.pdf
Can be found on eBay for a similar price to the Anaheim ones, and they ship to Europe for a reasonable charge.
Thanks!
I have been trying to find alternatives to the Anaheim motors, mostly because they seem to take too long to get in stock, as well as due to the prohibitive shipping ($150 to Europe - which seems much).
While I understand that the amp was made to support specifically the two Anaheim motors, can you spare some time and look into this option:
http://www.zhengkemotor.com/upload/file/20140109_164856.pdf
Can be found on eBay for a similar price to the Anaheim ones, and they ship to Europe for a reasonable charge.
Thanks!
Those dimensions sound about right; you will need to fine adjust the frequency to get the exact speed.
You will also need to adjust the voltage to the motor; the slower the speed, the lower the drive voltage needed to maintain constant power. Use the pots to set output voltage when the SG4 is set to maximum (128):
A 267 RPM motor will be driven by ~17.8Hz and the output voltage should be 7.4VPP (scope) or 2.61VRMS (meter).
A 355/360 RPM motor will be driven by ~24 Hz and the output voltage should be 8VPP or 2.83VRMS.
A 480 RPM motor will be driven by ~32Hz and the output voltage should be 9VPP or 3.18VRMS.
Once the pots are set, you set the SG4 reduced voltage lower to reduce the power consumption to ~75% of maximum.
Those motors have a built in controller and would not be compatible with the SG4 or MA-3D.
Look at these motors for possible overseas replacements:http://www.diyaudio.com/forums/anal...hase-bldc-motor-turntable-21.html#post5090793
@Pyramid, you had said that RPM using this method (SG4) is dependent on frequency and number of poles per motor.
Just checking, with this motor:
https://www.alibaba.com/product-det...60547562510.html?spm=a2700.7724838.0.0.ZVjPJ1
Is 6000RPM rating a bit too high? Are there any issues running a 6000rpm rated motor at 5% of its rated speed?
Also, I am sure you have shared this, but cannot seem to find it - can you please let me know how to calculate the output voltage for the motor for a particular frequency?
Just checking, with this motor:
https://www.alibaba.com/product-det...60547562510.html?spm=a2700.7724838.0.0.ZVjPJ1
Is 6000RPM rating a bit too high? Are there any issues running a 6000rpm rated motor at 5% of its rated speed?
Also, I am sure you have shared this, but cannot seem to find it - can you please let me know how to calculate the output voltage for the motor for a particular frequency?
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I should clarify: I wasn't recommending any one of those motors; I was supplying a different source for a multitude of motors that the user should try to match the mfr's specs against those of the AA motors. The AA motors both spec 2000 RPM as rated speed. You would want to find a motor with similar speed, power, # of poles and DC winding resistance as the AA motors.
I have a call in to the sales manager at AA; apparently they only ship UPS/FedEx overseas, but I'm going to make the case to ship via US Postal which will be much cheaper. A person ordering these motors might make the same request.
It is easier to measure than to compute it. The motors should not be run hotter than the rated power (12W) at any speed. Measure the total DC current going into the amp and assume 95% efficiency. If the power supply is 24VDC then 0.5A will give you ~12W. If you lower the frequency, the current consumption will increase. Decrease (or increase if going up in freq) the voltage to maintain 0.5A at all speeds.
