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
A Lady Writing a Letter A Lady Writing a Letter A Lady Writing a Letter (also known as A Lady Writing; ) is an oil painting attributed to 17th century Dutch painter Johannes Vermeer. It is believed to have been completed around 1665. The Lady is seen to be writing a letter and has been interrupted, so gently turns her head to see what is happening. She wears twelve pearls (10 on the necklace and two earrings). Many of the objects seen in the painting, such as the woman's coat, the cloth on the table, and the string of pearls, also appear in other Vermeer