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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 ...
A colour chart is used for this purpose in many contexts such as chemistry, cosmetics, medical testing and photography. Comparison by eye may also be used as a source of amusement or intelligence testing, as in the popular puzzle of spot the difference. In policing, the technique is used for analysis of fingerprints and identity parades.
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.
Contrast is the difference in luminance or color that makes an object (or its representation in an image or display) visible against a background of different luminance or color. [1] The human visual system is more sensitive to contrast than to absolute luminance; thus, we can perceive the world similarly despite significant changes in ...
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 ...
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
Livegap Charts creates line, bar, spider, polar-area and pie charts, and can export them as images without needing to download any tools. Veusz is a free scientific graphing tool that can produce 2D and 3D plots. Users can use it as a module in Python. GeoGebra is open-source graphing calculator and is freely available for non-commercial users.
Examples of computer clip art, from Openclipart. Clip art (also clipart, clip-art) is a type of graphic art. Pieces are pre-made images used to illustrate any medium. Today, clip art is used extensively and comes in many forms, both electronic and printed. However, most clip art today is created, distributed, and used in a digital form.