Circle diagram constant air-gap induction motor images shown here, where, The circle diagram is drawn using the data obtained from no load and either short circuit or, in case of machines, blocked rotor tests by fitting a half-circle in points O and A. Beyond the error inherent in the constant air-gap assumption, the circle diagram introduces errors due to rotor reactance and rotor resistance variations caused by magnetic saturation and rotor frequency over the range from no-load to operating speed. Steinmetz equivalent circuit Circle diagram First conceived by A. Heyland in 1894 and B.A. Behrend in 1895, the circle diagram is the
Ida Reading a Letter Ida Reading a Letter Ida Reading a Letter is an 1899 painting by Vilhelm Hammershøi. It is an example of a work inspired by Dutch Golden Age painting and is currently in a private collection. In 1887 Hammershoi travelled to the Netherlands, where he saw works by Vermeer and his Delft contemporaries first-hand. This painting shows many characteristics of such room interiors, usually featuring a woman at an everyday task. This painting seems to have been directly inspired by a Vermeer he would have seen in Amsterdam, "Woman in Blue Reading a Letter". The use of the hairstyle, pose, table