Motor Drive Overview & Operation
(scroll down below the photo for a quick-start guide to operation)
This guide documents the operational characteristics and design philosophy of the drive system released in the late Winter of 2014. It will be updated with video support.
The new generation drive represents a considerable departure from the legacy drive:
- High torque, low RPM.
- Larger pulley for better belt traction. A large pulley would not be possible with a low torque motor.
- Closed loop operation for speed lock & long term speed stability.
- Works well with wall powered, DC linear power supply (battery may still be used).
- Specified with seamless (no splice) Kapton belt. Mylar may still be used (see drive belt support).
- Finer speed adjustment – set and forget.
The drive requires 45 seconds to lock onto speed. This occurs upon powering up or when changing speed from 33 to 45 or vice versa.
Recommendation: leave your controller powered up throughout a listening session.
Comment: The high torque upon startup lends the impression that the motor is up to speed within 1-2 seconds. Full locking occurs however at 45 seconds. This minimizes the effect of the sensor circuit on speed stability at the “micro” level (below the threshold of perceived wow and flutter).
Operating Changes from the Legacy Drive System
In addition to the speed lock characteristics noted above, the key operational differences you’ll note from the legacy drive are:
- Much more precise speed adjustment. This was accomplished by dedicating each switch position (trim pot) to a specific speed. The pots are no longer assignable to either speed.
- Separation of functionality into two switches – one to select speed and one to enable the controller.
- Revised power on/off sequence (see below).
- Power switch: The switch on the external power supply (not applicable if you use a battery).
- Enable (on/off) switch: The switch on the controller – think of it as the start/stop switch.
Power on Sequence
- Turn on the power supply (power switch). Not applicable if you’re using a battery.
- Turn on enable switch.
Note: If you turn on the enable switch before the power supply switch, the motor won’t turn on. This is normal. Cycle the enable switch off and then on again by pressing it twice. This will reset the controller and resume normal operation.
Power off Sequence
Turn off both the power supply (power switch) and the controller (enable switch). Order does not matter. If using a battery, then turn off the enable switch.
Note: if you forget to turn off the enable switch, the controller will not send power to the motor the next time you power up. This is normal (see above). Merely cycle the enable switch off and then on to reset and resume normal operation.
Press the speed selector switch to alternate between 33 & 45 rpm. The blue LED indicates 33 rpm operation, and the red LED indicates 45 rpm. The controller will “remember” the last speed selected when powered off and then on again.