What is the switch

 115/120 V AC Voltage and Three-phase Phase small 240v electric motor
Specifications
1.Specifications1.3-phase asynchronous motors 
2.IEC standard 
3.OEM 
4.Voltage:50HZ &60HZ;380V&415V 
5.Protection class: IP54 
Exchange "and" switch "originating in telephone communication system (PSTN). We often see in movies or TV before some old movies often see people on the telephone a couple of shakes madly (note not dial), and ac electric motor then said to me by XXX, after the telephone operator received requirements will take corresponding backcourt head in to terminal, can talk to each other. In fact this is the most primitive telephone exchange system, it is just a kind of artificial telephone switching system, is not automatic, and it's not what we want to talk about today, program-controlled switches, but we now speak of SPC exchange, that is, on the telephone exchange technology development. Since the United States bell invented the telephone in 1876, with the increasing of social demand and constantly improve the level of science and technology, telephone switching technology is in rapid change and development. 

DONGFENG Brand Two Speed Motor
Specifications
1. DONGFENG Brand Two Speed Motor 
2. 3000RPM-750RPM 
3. Electrical motor 
4. factory price best quality 

5. 100% copper 
The process can acmotor2.blogspot.com be divided into three stages: artificial exchange, exchange of mechanical and electrical and electronic exchange. As early as 1878 appeared a manual switchboard, it is by the operator to call in, obviously its efficiency is very low. 15 years hind leg into the system switches, it marks the switching electric motor low rpm from manual times into the mechanical and electrical switching times. This switch belongs to the "direct control" mode, that is, the user can through the telephone to dial directly controlled pulse stepper connector for lifting and spins. To complete the user automatically in between. This switch has realized automatic succeeded, but there is a low speed, low efficiency, big noise and mechanical wear serious shortcomings and so on.

Three-phase asynchronous motor current sampling resistance

Sampling resistance is also known as current resistance, electric flu resistance measurement, sampling resistance, current induced resistance. General English translated into from resistor, Current sensing resistor. With simple words description is a resistance smaller resistance, series in the www.dongfeng-motor.com circuit used in the current into a voltage signal is measured. Such resistance, it is divided according to the function of the products use resistance. Sampling resistance function is used as the reference, commonly used in a feedback circuit, stabilized voltage supply circuit, for example, to make the output voltage constant state, want to part from the output voltage is the voltage for your reference (the form of generator set spare parts commonly used sampling resistor), if the output is high, the input is automatically reduced voltage, reduce the output; If the output is low, the input is raising voltage automatically, try output to rise. 


Commonly used in power supply products, or electronic, digital, power supply part of the mechanical and electrical products, powerful. In numerous electronic products are often see sampling resistor. Sampling resistance generally use is precise resistance, low resistance, high precision, generally in resistance precision within + / - 1%, higher requirement of use when resistance with 0.01% accuracy. The majority of domestic production is based on manganese bronze material plug-in small diesel generator resistance, however, the majority of users have more need of strips of high precise resistance to achieve the function sampling, this is in order AC synchronous generator to meet the requirements of product miniaturization product production automation. Able to produce at low temperature coefficient, high precision, low on resistance to meet user requirements manufacturers in domestic is very little resistance.