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The circle diagram can be drawn for alternators, synchronous motors, transformers, induction motors. The Heyland diagram is an approximate representation of a 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.
According to ISO 764 or its equivalent DIN 8309 (Deutsches Institut für Normung - German Institute for Standardization) a watch must resist exposure to a direct current magnetic field of 4800 A/m. The watch must keep its accuracy to ±30 seconds/day as measured before the test in order to be acknowledged as a magnetic-resistant watch.
A DC motor consists of two parts: a rotor and a stator. [3] The stator consists of field windings while the rotor (also called the armature) consists of an armature winding. [ 4 ] When both the armature and the field windings are excited by a DC supply, current flows through the windings and a magnetic flux proportional to the current is produced.
Traditionally, the magnetizing field, H, is measured in amperes per meter. Magnetic induction B (also known as magnetic flux density) has the SI unit tesla [T or Wb/m 2]. [1] One tesla is equal to 10 4 gauss. Magnetic field drops off as the inverse cube of the distance ( 1 / distance 3 ) from a dipole source.
In order to represent the magnetic response of a linear material with permeability μ, this instead appears as a magnetization M that arises in response to the B field: = (). The magnetization in turn is a contribution to the total electric current—the magnetization current .
The universal motor is a type of electric motor that can operate on either AC or DC power and uses an electromagnet as its stator to create its magnetic field. [1] It is a commutated series-wound motor where the stator's field coils are connected in series with the rotor windings through a commutator. It is often referred to as an AC series motor.
A compound DC motor connects the armature and fields windings in a shunt and a series combination to give it characteristics of both a shunt and a series DC motor. [5] This motor is used when both a high starting torque and good speed regulation is needed. The motor can be connected in two arrangements: cumulatively or differentially.
A diagram of the device Newman's Energy Machine was a DC motor which the inventor, Joseph Newman , claimed to produce mechanical power exceeding the electrical power being supplied to it. In 1979, Newman attempted to patent the device, but it was rejected by the United States Patent Office as being a perpetual motion machine . [ 1 ]