Air compressor (compressor) is commonly used in electrical equipment factory, generally controlled by the electrical contacts. Circuit shown in Figure 5-1. Circuit automatic an
d manual operation. Figure, KP as electrical contacts, when the air pressure reaches the upper limit (such as 0.6MPa), the 13 contact closure; when the air pressure starts below the lower limit (eg 0. 4MPa), the contacts 1-2 closure. By the control circuit, the gas tank can always be maintained at a pressure within the range of 0.4 ~ 0. 6MPa required.