Patent ID: 7663335

Claim:
A single-phase induction motor comprising a main winding, an auxiliary winding, and a run capacitor, the motor further comprising: a start capacitor; a start device to produce a high start torque when the motor starts, said start device including a positive thermal coefficient element (PTC) having a low resistance at low temperature; and a power consumption preventor to prevent current from flowing to the start device to prevent power consumption by the start device when the motor runs in normal mode, wherein the power consumption preventor comprises a current transformer including a primary coil and a secondary coil, the primary coil being connected in series with one end of the main winding and with another end of the primary coil being connected to a power source, to generate a current signal based on a current being induced in the secondary coil according to an amount of a current provided to the primary coil, wherein the current signal is transferred to a switching element, connected in series with the start capacitor and the PTC, to control current flow to the PTC, such that when the current signal is received from the secondary coil and when the motor runs in normal mode, the switching element turns off and prevents current from flowing to the PTC.