Hi
I have a small Leybold TMP50 turbo pump, but have blown the controller in a flash x-ray tube driven by a marx-generator experiment. The pump can be opened and allow a look to the motor. The motor has only 3 wires ( delta circuit ? ) and looks like a normal short circuit rotor asynchron motor. I found even used controllers are very expensive so I have to build my own one. The first idea was to use a audio amplifier and generate the drive for the third connection with a capacitor. But a the run-up of the pump the drive frequency change from a round 10 Hz to 800 Hz and I think also the capacitor should be change according to the frequency change. Changing a capacitor from estimateds 4 µf down to arround 0.1 µF is not a easy task.
Perhaps one could use a controller for the meantime very popular brushless modell motors. The controllers a really cheap, and the power requirements of the pump ( 48 V, 3A) should be possible with upper range controllers. In the moment I don't know what kind of driving signals this controllers need but it shouldn't be to difficult to find out.
Thomas