起重机设计的这一部分包括电源、电动机、制动器、控制、电阻器、保护装置、限位开关、导线和控制装置。这些设备是构成每一台起重机的重要组成部分。其它电气设备被看作附件另行研究。因为电气设备的来源很多,它们的结构、型式和容量最好由起重机制造厂在充分了解起重机的工作要求以后提出来。电源对于起重机运转,可以利用两种电源:直流电和不同电压和频率的交流电。起重 This part of the crane design includes power supplies, motors, brakes, controls, resistors, protectors, limit switches, leads and controls. These devices form an important part of every crane. Other electrical equipment is considered as an attachment for further study. Because of the many sources of electrical equipment, their structure, type, and capacity are best suggested by the crane manufacturer after fully understanding the crane’s job requirements. Power Supply For cranes, two types of power supply can be used: DC and AC with different voltage and frequency. Lifting