【正文】 st piece of four 4004 Intel microprocessor chips, marks the first generation of microprocessor market, microprocessor and puter era begins. For invention microprocessor, hoff by the British economist magazine named the most influential since world war ii the seven scientists one. In 1971, the Intel on November launch MCS 4 microputer system (including 4001 ROM chip, 4002 RAM chips, 4003 shift register chips and 4004 microprocessor) which 4004 (figure below) contains 2,300 transistor, the dimension of 3mm x 4mm, puting performance than that ENIAC, initially sells for $200. April 1972, hoff etc, developed the first eight Intel microprocessor 8008. Because 8008 USES is P in gully MOS microprocessor, and therefore still belong to the first generation of microprocessors. 1973 Intel pany develop 8 bits of the microprocessor 8080。 The single chip puter abbreviation Microcontroller is typical of embedded Microcontroller controller (Microcontroller Unit), mon English letters is the abbreviation of MCU said Microcontroller, it was first used in industrial control field. SCM by chip inside only CPU dedicated processor. The earliest design concept is through the huge amounts of peripheral and CPU integration in a chip, make the puter system smaller, more easy to integrate into the plex and to volume demanding control equipment of. Intelbased Z80 is the earliest designed according to this kind of thought the processor, henceforth, SCM and dedicated processor development parted. Early microcontroller is 8 bits or 4 digit. One of the most successful intelbased 8031 is simple, reliable performance, because good got a lot of praise. Then in the microputer 8031 developed MCS51 series microcontroller systems. Based on this system of SCM system have until now in widespread use. With the improvement of industrial control area requirement, begin to emerge 16bit single chip, but because the price is not ideal did not get very widely. After the 1990s with consumer electronic products development, microcontroller technology has been a tremendous increase. As the INTEL i960 series especially later ARM series widely, 32bit SCM rapidly replacing 16bit single chip of highend status, and into the mainstream market. While the traditional 8 bit microcontroller performance also obtained the rapid increase, processing power than 1980s raised hundreds times. At present, highend 32bit SCM frequency has exceeded 300MHz, performance straight after the middle of 9039。 In 1973, August hoff person such as developed eight microprocessor 8080 to N in gully intelbased MOS circuit replaced P channel, the second generation microprocessor at birth. Frequency of 2MHz 8080 chip speed 8008 10 times faster than, can access 64KB memory, use based on six micron technology 6,000 transistors, processing speed of the MIPS (at) Million will conference. In 1975, MITS issued on April first generalpurpose Altair 8,800, price $, with 1KB memory. This is the world39。and39。s second feature is pletely automatic, no need to use mand to convert. Such as , , respectively, are WR, RD signal, when the microchip RAM or external justifications machine has an external I / O port, they were used as the second function, can not be used as generalpurpose I / O port to use, as long as one microprocessor implementation of the MOVX instruction 1, there will be a corresponding signal sent from the or , no prior use instructions indicate. In fact 39。 but (user) 39。, so the procedure always39。0000 39。advanced after that lastin firstout 39。 POP 39。 Or large inertia load such as: fan, cement system pipe, Dynamic balancing machines etc。 , energy feedback unit applies to need to stop quickly of occasions, such as rolling mill, large longmen planer, spindle etc, , energy feedback unit work may apply to other motors in renewable power state occasions. Four, energy feedback element and braking unit difference Energy feedback unit is renewable power of electric motor to power grid (right now meter feedback inversion), supply other equipment use, feedback efficiency can reaches as high as 97% above. And braking unit needs and braking resistance are used together, motor power generation of electricity consumption in regenerative braking resistance into heat wasted. In addition, using braking unit and braking resistance of braking unit, pared with energy feedback braking torque is small, can39。t use this energy consume, so with dc bus voltage will rise, the influence of the frequency converter working normally. Energy feedback unit, through the automatic detection inverter with dc bus voltage, frequency converter dc link of dc voltage inverter with frequency voltage into with the same phase ac voltage, via multiple noise filter link after connected to exchange work, so as to achieve the purpose of energy feedback work, back to the grid electricity generating energy reached 97%, and effectively save electric energy. Second, energy feedback unit matters needing attention , energy feedback unit and its connected device internal have endanger the personal safety of high pressure, wrong operation or improper installation may lead to personal property loss, so that the proposed by specially trained personnel installation operation. , installation and wiring, in order to ensure the safe, please make sure to energy feedback unit and connected to it inverter power supply all disconnect and waits for 5 ~ 10 minutes, stay inverter internal capacitance stored in electricity discharge is finished, all can only operate. , energy feedback unit and converter as close as possible to the farthest distance, do not exceed 2 meters. , because energy feedback unit interior special design allows the user can not consider the grid sequence, namely: energy feedback unit of A, B and C terminals need not to the grid A, B and C or frequency conv