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A VFD operates on the principle of cathodoluminescence, roughly similar to a cathode-ray tube, but operating at much lower voltages. Each tube in a VFD has a phosphor-coated carbon anode that is bombarded by electrons emitted from the cathode filament. [1] [2] In fact, each tube in a VFD is a triode vacuum tube because it also has a mesh ...
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 ...
With a variable-speed drive on the pump or fan, the supply can be adjusted to match demand and no extra loss is introduced. For example, when a fan is driven directly by a fixed-speed motor, the airflow is designed for the maximum demand of the system, and so will usually be higher than it needs to be.
If a variable speed drive compressor operates continuously at full speed, the switching losses of the frequency converter result in a lower energy efficiency than an otherwise identically sized fixed speed compressor. Where demand remains constant within 5–15% of the total free air delivery flow rate, dual-control compressors configured in a ...
VSD (French magazine) (Vendredi Samedi Dimanche; i.e. "Friday Saturday Sunday"), a French weekly news magazine; Vaccine Safety Datalink, a Centers for Disease Control database containing vaccination and health records of over 7 million Americans; Variable speed drive, or adjustable-speed drive, is a specific type of a variable-frequency drive
The table/chart/clade doesn't belong here but rather in the other article. This article is a subtype of variable speed drive, of which there are many beyond just electronic means. That DoE PDF says this right in the 2nd paragraph of the first page: Speed can be controlled in a number of ways, with the most popular type of variable speed drive ...
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General parameters used for constructing nose cone profiles. Given the problem of the aerodynamic design of the nose cone section of any vehicle or body meant to travel through a compressible fluid medium (such as a rocket or aircraft, missile, shell or bullet), an important problem is the determination of the nose cone geometrical shape for optimum performance.