Switch the role of the two

 Cast Iron electrical motor auto spare parts 
Specifications
1. 20 years manufacturing experience 
2. competitive price,high quality
3. Delivery Detail:within 10 days after receiving deposit 
The PBX is the organ of industrial enterprises and mines in the internal telephone switching a special-purpose switches, its basic function is to complete the unit internal users can talk to each other, but also is equipped with in and out of the trunk can be connected to the PSTN network and network in the city of user calls (including local calls, domestic long distance calls and international calls). Because this kind of exchange is a special unit interior, therefore, can according to customer's need to increase the number of additional properties for the ease of use. So this kind of switch has great flexibility. ANP gost motor The PBX is an important part of the option, is one of the local switches added equipment, because it is used for a lot of traffic between the unit internal users, reduce the traffic load option. 


gost motor 7.5kw

Specifications
1. effiency: IE2 and IE1 
2. 20 years manufacturing experience 
3. 12 months guarantee 

4. low noise and vibtration
Another user switches scattered in electric generator various units set, closer to the user, thus shortening the distance between the subscriber line, save the cable users. At the same time with a small number of discrepancy trunk access option, have the effect of traffic concentration. In these ways, using the PBX has great economic significance. Therefore, in the construction of public network cannot lack the PBX. User switches on Single phase motor the technology of using SPC is the development trend of the PBX, adopts the new type of program-controlled digital subscriber switches can not only exchange phone business, and can exchange data, and so on the words business, achieve a variety of business exchange and transmission.

Sensorless brushless dc motor control - a back emf method

 AC induction cooling fan motor 
Specifications
1. Customised
2. good quality
3. 20 years manufacturing experience
4. Altitude: ≤1000m

Assume that during the T T 1 0 ~ G5, G6 conduction, dangling a photograph, as shown in figure 1 (a), is a phase back emf ea = U an (a) phase voltage phase, a phase voltage U ag = U + U ng = an ea + U ng. At t0 time, ea = 0, b and c two phase current, on the other hand, and that the impedance is equal, and by the small diesel generator back emf waveform is known: the eb + ec = 0, so U ng = 1/2 U d, so U ag = ea + U ng = 1/2 U d. As long as it can detect or U an U d (U ag - 1/2) of the zero point, can be indirectly detect the zero moment of ea. Because the testing point ahead of the next converter 30 °, can be after 1/12 inverter cycle delay, shut off the G5, trigger conduction G1, which can ensure the maximum average electromagnetic torque motor can continuously produce. Repeat the above process, detection of ea in turn another zero and eb, ec all zero, and also delay, in turn trigger conduction of generator set spare parts a, b, c three-phase bridge arm up and down, to ensure the correctness of the permanent magnet brushless dc motor reversing sequence. 


Y2 series electric motor wholesale

Specifications
1. effiency: IE2 and IE1 
2. 20 years manufacturing experience 
3. 12 months guarantee 
4. low noise and vibtration 

5. AC Voltage: 220V/380V, 380V/660V,400V/690V,220V/400V

According to different detection objects, and the detection method can respectively called phase voltage method (test U an), the terminal voltage method (U ag). Among them, the terminal voltage method, the application of more. In terminal voltage method, in order to realize the phase voltage of zero crossing detection, first U ag, U can be the bg, U CG input low pass filtering devices, respectively, in order to eliminate the can seriously interfere with the back emf waveform, that there is no clear chopper signals passing zero [4]. And then use www.facebook.com/dongfeng.motor a voltage comparator, respectively each phase voltage compared to zero level, according to the comparison results of coding signal encoding, to get the rotor position signal. At present, the selection of zero level as shown in figure 2 [2], mostly by V, V b, V c three-phase symmetric star connection level V 0 instead of the center of the resistance of the circuit. Abroad recently put forward a new method: the three opposite electric potential (replace) with phase voltage first by square wave into a balanced three-phase sine wave, again through the star connection, get the central level, instead of a zero level. This method can get accurate "0" (zero after balanced three-phase sine wave synthesis), can reduce the position detection error.

From abnormal vibration of asynchronous motor and how to determine the cause of the problem in his voice?

 Stator Motors Rotor 
Specifications
1. 20 years manufacturing experience 
2. competitive price,high quality 
3. Brand Name: FUJIAN DONGFENG MACHINERY ELECTRICAL LIABILITY CO., LTD

Asynchronous motor produce abnormal vibration and abnormal sound mainly has two aspects of mechanical and electromagnetic. Mechanical reasons: (1), motor blades damage or tighten screw loose blades, blades and the blades into cover, clattering sound produced by it with the weight of the sound, the big small; (2), due to the improper bearing wear or shaft, motor rotor eccentricity caused serious when will make, rotor rub, make the motor produces severe vibration and electric fan motor uneven scratches. (3), motor due to long-term use of the anchor bolt is loose or not foundation, thus the electromagnetic torque of the motor under the action of abnormal vibration; (4), long-term use of the electric motor 12v 500w motor due to a lack of lubricating oil in the bearing inner formed in mill run or bearing steel ball is damaged, therefore make the hiss of the motor bearing interior an exception or purr. Electromagnetic reasons: (1), the normal operation of the motor suddenly appear abnormal sound, in the load running speed decreases significantly, while a low along the roar, may be unbalanced three phase current, the heavy load or single phase operation; 


Y series best cast iron three phase induction motor

Specifications
1. 20 years manufacturing experience 
2. 12 months guarantee 
3. low noise and temperature rise 
4. high starting torque 

5. AC Voltage: 220V/380V, 380V/660V,400V/690V,220V/400V

(2), the normal operation of the motor, if the stator and rotor winding short-circuit fault ac induction motor 110kw or squirrel cage rotor broken bar when electric are high when low buzz. The fuselage vibration. (1), due to long-term lack of oil running of motor bearing, friction losses increase bearing overheating. In addition, when the motor running, the oil too much or too thick will also cause bearing overheating; (2), when the replacement of lubrication, due to the lubricating oil mixed with hard grain impurity or bearing cleaning uneven net, make bearing wear and overheating, even may damage the bearing; (3), due to improper assembly, fixed end cover wholesalemotor.blogspot.com screw tightness is differ, in a straight line between the two bearing center is unbalanced or bearing outer ring. The bearing rotation is not flexible, adds load after growing friction and heat; (4), belt too tight or motor and were not in a straight line with mechanical shaft center, and thus can increase the bearing load and heat; (5), bearing improper selection or poor quality, such as bearing internal and external ring rust, individual steel ball is not round, etc.; 6, in the operation of the motor bearing damaged, resulting in bearing overheating.

The role of the current transformer is used to measure the larger current

The role of the current transformer is used to measure larger current, current transformer is a kind of current commutation device, symbols for CT. Its role is to put the large current into a small current, supply measuring instrument and relay the current chart, indirect measurement by large current. But also can isolate high voltage, to ensure the safety of staff and secondary equipment. Current transformer secondary side current is 5 Why can't a current transformer secondary side circuit? Current transformer secondary side is not allowed to open operation. In the current transformer secondary coil on the instrument coil impedance is small, the equivalent of running in the secondary coil short-circuit condition. Transformer secondary coil terminal voltage on only a few volts. Of the magnetic flux in core is very small. Although primary coil magnetomotive force can reach hundreds or thousands of Ann ampere-turns or larger. But most were established by short circuit secondary coil demagnetization magnetomotive force offset, only a small fraction of excitation magnetomotive force as the core to establish a magnetic flux in the core. 


If in running the secondary coil disconnection, vice side current is equal to zero, then the demagnetization effect of magnetomotive force disappears, and the original edge of magnetomotive force is constant, the original edge measured current all become excitation current, this will make the iron core of sharp, magnetic ac motor flux core severe fever that burn out the coil insulation, or make the high side of short circuit. Other electric fan motor secondary coil wholesalemotor.blogspot.com open out the high voltage is induced, it is very dangerous for instrument and operators so current transformer secondary side is not allowed to disconnect. Why can't a voltage transformer secondary side short circuit? If the short circuit in the operation of the secondary side lamination of voltage transformer, secondary coil impedance decrease greatly, can appear a lot of short circuit current, make the secondary coil burned due to severe fever. So in the operation of the transformer are not allowed to short circuit. General voltage transformer secondary side with a fuse. Only transformer of 35 kv and below, on the high side have a fuse when transformer short-circuit the purpose is to put it cut off from the high voltage circuit.