Status detection device, image forming apparatus including the same, and method for controlling status detection device

The present invention provides a status detection device, an image forming apparatus including the same, and a method for controlling the status detection device. The status detection device includes a heater, a first power line for supplying power to one end of the heater, a second power line for supplying power to the other end of the heater, a switch portion disposed in the first power line, an overheat protection portion for disconnecting the second power line when temperature exceeds a predetermined temperature, and a zero cross signal generation portion which outputs a zero cross signal in accordance with a waveform of an AC power supply, and outputs zero cross signals having different output values in a case where voltage of the first power line is higher than voltage of the second power line and in a case where the voltage of the second power line is higher than, the first power line.