| 摘要 |
An isolation speed regulation interface circuit and an electrical equipment system using same. The isolation speed regulation interface circuit is installed on a main control circuit board of an ECM electric motor and electrical equipment, and comprises a microprocessor, an isolation power supply and a signal isolation circuit, which are integrated onto a circuit board. The output end of the isolation power supply supplies power to various circuits, and the input end of the isolation power supply is connected to an external input power supply. An A/D conversion input port of the microprocessor is connected to an analogue voltage signal VSP, and the microprocessor converts the analogue voltage signal VSP to a PWM signal or variable-frequency signal with a certain duty ratio and outputs same to the input end of the signal isolation circuit. When the signal isolation circuit outputs a PWM signal with a certain duty ratio or a variable-frequency signal with value T0, the microprocessor selects a second level of speed S2 and controls the electric motor to operate constantly at the second level of speed S2. The circuit is simple in structure and low in cost, and the signal converted by a microprocessor MCU is high in precision and good in reliability. |
