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  2. Vacuum fluorescent display - Wikipedia

    en.wikipedia.org/wiki/Vacuum_fluorescent_display

    A vacuum fluorescent display (VFD) is a display device once commonly used on consumer electronics equipment such as video cassette recorders, car radios, and microwave ovens. A VFD operates on the principle of cathodoluminescence , roughly similar to a cathode-ray tube , but operating at much lower voltages.

  3. Variable-frequency drive - Wikipedia

    en.wikipedia.org/wiki/Variable-frequency_drive

    Small variable-frequency drive Chassis of above VFD (cover removed). A variable-frequency drive (VFD, or adjustable-frequency drive, adjustable-speed drive, variable-speed drive, AC drive, micro drive, inverter drive, variable voltage variable frequency drive, or drive) is a type of AC motor drive (system incorporating a motor) that controls speed and torque by varying the frequency of the ...

  4. Vector control (motor) - Wikipedia

    en.wikipedia.org/wiki/Vector_control_(motor)

    In vector control, an AC induction or synchronous motor is controlled under all operating conditions like a separately excited DC motor. [21] That is, the AC motor behaves like a DC motor in which the field flux linkage and armature flux linkage created by the respective field and armature (or torque component) currents are orthogonally aligned such that, when torque is controlled, the field ...

  5. Frequency changer - Wikipedia

    en.wikipedia.org/wiki/Frequency_changer

    A variable-frequency drive (VFD) is a type of frequency changer used for speed control of AC motors such as used for pumps and fans. The speed of a synchronous or induction AC motor is dependent on the frequency of the AC power supply, so changing frequency allows the motor speed to be changed.

  6. Direct torque control - Wikipedia

    en.wikipedia.org/wiki/Direct_torque_control

    The intermediate DC circuit's voltage variation is automatically taken into account in the algorithm (in voltage integration). Thus no problems exist due to dc voltage ripple or dc voltage transients; Synchronization to rotating machine is straightforward due to the fast control; Just make the torque reference zero and start the inverter. The ...

  7. File:Electrical VFD Diagram, 2phase to 3phase.svg - Wikipedia

    en.wikipedia.org/wiki/File:Electrical_VFD...

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  8. Variable-speed air compressor - Wikipedia

    en.wikipedia.org/wiki/Variable-speed_air_compressor

    The most common form of VSD technology in the air compressor industry is a variable-frequency drive, which converts the incoming AC power to DC and then back to a quasi-sinusoidal AC power using an inverter switching circuit. The variable-frequency drive article provides additional information on electronic speed controls used with various ...

  9. Chopper (electronics) - Wikipedia

    en.wikipedia.org/wiki/Chopper_(electronics)

    Schematic of an inverter using a vibrator as a chopper. In electronics, a chopper circuit is any of numerous types of electronic switching devices and circuits used in power control and signal applications. A chopper is a device that converts fixed DC input to a variable DC output voltage directly.