https://electronics.stackexchange.com/questions/613314/1-phase-motor-supplied-with-3-phase-supply
https://www.google.com/url?sa=i&url...2ahUKEwjn-4fG8Z-EAxXRamwGHSJgD6AQr4kDegQIARBY
Google and other search engines:'Running 3 phase delta motor from single phase diagram'
Many ideas..see the results.
https://www.google.com/url?sa=i&url...2ahUKEwjn-4fG8Z-EAxXRamwGHSJgD6AQr4kDegQIARBY
Google and other search engines:'Running 3 phase delta motor from single phase diagram'
Many ideas..see the results.
This (the left hand side diagram) is the method used for pretty much all turntables that use the Papst Aussenlaufer motors.
It works well, but is much improved when the PSU is replaced by a synthesized 3 phase supply such as the SG4.
The issue with running a 3 phase motor on a single phase + capacitor is that the phase shift is never perfect and there is always some residual vibration. Conversely, a genuine 3 phase supply with each phase 120 degrees apart from the others will always sum the currents in the 3 phases to 0, providing an almost totally vibration free rotation.
This is especially true for the hysteresis motor that has no magnetic field in the rotor except that induced by the stator.
This is even more the case when small discrepancies in the accuracy of the windings can be compensated for by small adjustments of the phase shifts.
By this means it is possible to create a motor drive where vibration is reduced to such a degree as to make it practically impossible to tell if the motor is running.
Only a DC motor with an ironless rotor can compete with this, but has it's own issues with brushes which wear in time, and tends also to drift with time unless compensated by a feedback method of some sort.
It works well, but is much improved when the PSU is replaced by a synthesized 3 phase supply such as the SG4.
The issue with running a 3 phase motor on a single phase + capacitor is that the phase shift is never perfect and there is always some residual vibration. Conversely, a genuine 3 phase supply with each phase 120 degrees apart from the others will always sum the currents in the 3 phases to 0, providing an almost totally vibration free rotation.
This is especially true for the hysteresis motor that has no magnetic field in the rotor except that induced by the stator.
This is even more the case when small discrepancies in the accuracy of the windings can be compensated for by small adjustments of the phase shifts.
By this means it is possible to create a motor drive where vibration is reduced to such a degree as to make it practically impossible to tell if the motor is running.
Only a DC motor with an ironless rotor can compete with this, but has it's own issues with brushes which wear in time, and tends also to drift with time unless compensated by a feedback method of some sort.
The Fairchild 412-1 wasn’t “designed to price” - it was the most expensive 12” turntable available in the late 1950s and early 1960s, ahead of the Garrard 301, Scott 710, Rek-O-Kut B12H, and the Thorens TD-124. The Papst Aussenlaufer motor used in the first 2/3 of production was intended to work with a 4-speed vacuum tube VFD (the 412-ED) that doubled the price of the already eye-wateringly expensive base unit. As near as I’ve been able to figure from serial numbers, there were likely less than 100 electronic drive units built, probably due to the staggering price tag.