In the electricity supply lines, the current difference from a few to tens of thousands Ann Ann, the voltage difference from a few volts to several million volts. Line current and voltage are high, such as direct measurement is very dangerous. To facilitate secondary instruments need to convert to a more unified measure current and voltage transformers, converter transformers using transformers play the role and electrical isolation. Different types of transformers (9) indicator majority of current and voltage table pointer, so the majority of the current transformer secondary current is the ampere level (eg, 5, etc.). With the development of the times, the power measurement has been achieved mostly digitized and sampled signal computer is generally milliamps (0-5V, 4-20mA, etc.). Micro current transformer secondary current high-voltage transformer milliamps Yiyang, mainly from the large transformer and a bridge between samples. Micro current transformer called "Instrument current transformer." ("Instrument current transformer" There is a layer of meaning in the laboratory using a more precise than current high-voltage transformer current transformer Changsha, generally used to expand the range of the instrument is mainly used in AC circuit monitors the operation of electrical equipment and control systems (usually referred to as its primary winding primary winding or primary winding, the secondary winding is called secondary winding or secondary winding), respectively, for the measurement instruments, voltage and current coil power relay coil correctly reflect the normal electrical equipment operation and fault conditions. The accuracy and reliability of measurement instruments relay action, largely related to the performance of the transformer. Therefore it should be familiar with some of the major characteristics of transformers for proper selection and use of transformers. Zhengzhou high voltage power transformers _ Huayi (certified) _ transformers supplied by Huayi power plant in Xi'an, Xi'an Huayi power plant (www.xahy.com) is a leader in Xi'an high-voltage circuit breakers, over the years, the company implementation of scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. In Huayi Electric Power leadership with the staff warmly welcome all inquiries negotiations to create electricity Huayi a better future.