Bipolar stepper motor

 Bipolar stepper motor are so named mini electric motor because each winding can both directions electricity.So each winding can be N pole and can be the S pole.Stepping motor,it is also known as single winding because each only a single winding,it also referred to as two phase stepper motor,because has two separate coils.Bipolar stepper motor has four generator stator root lead,two each winding.With the same size and weight compared to the single step electrode polarity,bipolar stepper motor has a greater ability to drive,the reason is that the magnetic poles (not ask tap in a single coil) in electric motors 12 volt the field strength is twice the unipolar stepper motor.Bipolar stepper motor of each winding need a reversible power,usually provided by H bridge driving circuit.Because of the bipolar stepper motor than single polarity of stepper motor output torque,so is always used in the design of the space is limited.It is also a floppy disk drive head step into the mechanical system of driver is always adopt the cause of the bipolar stepper wholesalemotor.blogspot.com motor.To use digital multimeter can be quite simple to find two windings.If one could measure the resistance between two lead,then between the two leads are belong to a winding,the other two lines of q is another winding.Bipolar stepper motor of the interval is usually 1.8.Step,that is,200 a week.

Three automatically adjust the excitation current method

Three automatically adjust the excitation current method In the change of generator excitation

current,generally does not directly in the rotor circuit,because the loop current is very big,is not

convenient to adjust directly,usually adopted method is to change the excitation exciter Magnetic current,to achieve the purpose of regulating the generator rotor current.The commonly used method is to change the electrical resistance of the exciter excitation circuit,change the additional exciting current exciter,changing the conduction Angle of silicon controlled rectifier,etc.There are primary

change the thyristor turn-on Angle Method,which is based on the change of the generator three phase induction motor voltage,current,or power factor,accordingly change the conduction Angle of silicon controlled rectifier,so generator field current can change accordingly.The device generally by the transistor,thyristor electronic components,has a spirit Sensitive,rapid and no wholesalemotor.blogspot.com failure zone,big output power,the advantages of small volume and light weight.In accident cases can effectively inhibit overvoltage and achieve rapid out magnetic generator.

Automatically adjust the excitation device usually by measuring unit,synchronous unit,amplification unit, Controlled unit,stable unit,the limited unit and some auxiliary units.Be measured signals (such as voltage,current,etc.),compared with the given value after measurement unit conversion,and then compare the results (bias) the preamplifier unit and power amplifier unit Amplifier,and is used to control thyristor conduction Angle,in order to achieve the purpose of adjusting ac geared motor the generator excitation current.The function of synchronous unit is to phase shifting part of the output of the trigger pulse synchronization with silicon controlled rectifier ac excitation power supply,to ensure the correctness of silicon control triggering.Controlled unit is used in order to make the parallel operation of generator can be stable and reasonable allocation of reactive load.Stable unit is in order to 220v ac electric motor simprove the stability of power system and the introduction of unit.The excitation system stable unit To improve the stability of excitation system.limit Unit is in order to make the generator is not under the condition of excitation or underexcitation run.It must be noted that not every kind of automatic regulating excitation device has the various units,a regulator device of unit with its specific tasks The relevant.

Fault phenomenon:motor vibration is too large

Reason and solutions:1.The electric motor cooling fanrotor imbalance www.dongfeng-motor.com-leveling balance 2.Belt wheel unbalance or axis stretch bending-check and correction 3.Motor is not aligned to the load axis-check to adjust the axis of the unit motor fan4.Wrong-check the motor installation and foot screws 5.The heavy load suddenly, lighten the load

The load current of the motor with no load current, and power relations

Asynchronous motor no-load running, set the current in the three-phase winding, referred to as the no-load current. Most of the no-load current is used to produce a rotating magnetic field, known as the no-load excitation current, no-load current reactive component. There is a small part of no-load current is used to produce all kinds of power loss during no-load running (such as friction, ventilation and core loss), the no-load current is a part of the active component, due to account for the proportion of small, negligible. Therefore, can think of is reactive current idle current. From this point of view, it is as small as possible, so that www.facebook.com/dongfeng.motor the power factor of the motor raised, the power supply is good. If no load current is big, because of the stator winding conductors carrying area is certain, allowed through current is certain, allows for active current can reduce flows through a wire, the motor can drive the load will be reduced, the motor output is reduced, with too much load, winding would be easy to fever. 

But the no-load current also cannot too small, otherwise will affect the other performance of the motor. Generally the no-load current of the small motor is about 30% ~ 70% of rated current, ac synchronous motor the no-load current of the large and medium-sized motor is about 20% ~ 40% of rated current. What is specific to the no-load current of magnet generator an electric motor, the motor nameplate or product manuals, generally not marked. Have electrician often need to know how much is this value, this value to judge the quality of the motor repair, can use. (2) formula is the scene quickly calculate motor no-load current of specific numerical formula, it is a lot of test data. It is in line with "the no-load current of the motor is the 1/3 of its rated current". At the same time it is in line with practice experience: "the no-load current of the motor, shall not exceed the capacity of the kw number can be used for" the principle of (after repair of old, small capacity motor). Formula "capacity by about eighty percent for" refers to the general motor no-load current value is about 0.8 times the number of nominal capacity kw motor. No-load current of medium-sized, 4 or 6 pole motor, is the number of motor capacity kw 0.8 times; New series, large capacity, small number of level 2 of the motor, the no-load current calculation according to the number of "xinda sixty percent less"; To the old, old series, smaller volume, the number of large more than 8 pole motor, the no-load current, calculated on "is a small number of very many kilowatts", namely the no-load current value kw number approximately equal capacity, but is generally less than kilowatts.