Circle diagram Circle diagram First conceived by A. Heyland in 1894 and B.A. Behrend in 1895, the circle diagram is the graphical representation of the performance of the electrical machine drawn in terms of the locus of the machine's input voltage and current. The circle diagram can be drawn for alternators, synchronous motors, transformers, induction motors. The Heyland diagram is an approximate representation of circle diagram applied to induction motors, which assumes that stator input voltage, rotor resistance and rotor reactance are constant and stator resistance and core loss are zero. Another common circle diagram form is as described in the two
Woman in Blue Reading a Letter the quotidian, private moment becomes revealing of the human condition. The painting is unique among Vermeer's interiors in that no fragment of corner, wall or ceiling can be seen. Woman in Blue Reading a Letter Woman Reading a Letter () is a painting by the Dutch painter Johannes Vermeer. Part of the collection of the City of Amsterdam as part of the Van der Hoop bequest, it has been in the Rijksmuseum since its inception, and was thus the first Vermeer they acquired. The central element of the painting is a woman in blue standing in front of a window