Indoor motor control circuit of brushless motor air-conditioning system

The invention discloses an indoor motor control circuit of a brushless motor air-conditioning system. The indoor motor control circuit comprises a microcontroller U4, a motor speed control circuit of an indoor direct-current fan, an indoor motor speed regulation voltage cut-off circuit and a temperature detection circuit. The motor speed control circuit of the indoor direct-current fan and the temperature detection circuit are connected with the microcontroller, and the indoor motor speed regulation voltage cut-off circuit is connected with the motor speed control circuit of the indoor direct-current fan. The indoor motor speed regulation voltage cut-off circuit includes a first partial pressure shaping circuit, a first direct-current voltage detection circuit and a Vsp1 voltage cut-off circuit. The indoor motor control circuit of the brushless motor air-conditioning system has the advantages that speed of an indoor fan motor can be adjusted and controlled optionally, better heating effect can be achieved, and safety and reliability of the indoor motor in operation are improved and the like.