Ulvac UTM3400 Series, Instruction Manual

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3.3 Controller
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3
3.3
Controller
This product has a controller comprising a magnetic bearing control system that levitates the
rotors in a specific position inside the turbo molecular pump, a high frequency power supply
system that rotates the rotor at a specific speed, and a pump temperature control system. The
magnetic bearing control system levitates the rotor at a given position by using a gap sensor
inside the pump to detect the rotor position and controlling the electromagnet current. The high
frequency power supply unit first converts the commercial power supply to direct current, then
uses a three phase inverter to control AC frequency. If a power interruption occurs when the rotor
is rotating at high speed, the power supply unit uses the motor as a generator to control the
magnetic bearing with the regenerated power obtained. It does not use a battery as backup for
power interruptions.
Since it controls the turbo molecular pump externally, by remote control, the control system
includes RS-232C and RS-485 serial interface ports, in addition to input/output ports for contact
signals. The RS-232C and RS-485 ports allows monitoring the operating status and loading
history data. For more information regarding the serial interfaces, refer to Section 6.8
"Communication Specifications" and the separate Communication Functions manual.