An electric heating temperature control apparatus, using an AC power supply and connectable to an electric heating wire,
- the electric heating wire comprising a temperature sensing conductor, an insulating layer and a heating conductor, the temperature sensing conductor being configured for sensing a temperature of the heating conductor, the insulating layer being configured for insulation between the heating conductor and the temperature sensing conductor, and the insulating layer being configured for changing its resistance or resulting in a short circuit between the temperature sensing conductor and the heating conductor when a local or overall temperature of the heating conductor changes, and the heating conductor being configured for heating;
- wherein
- the electric heating temperature control apparatus comprises a temperature detecting circuit, a heating switching circuit and a temperature parameter setting circuit;
- the temperature detecting circuit comprises a temperature sensing voltage dividing and sampling unit, an AC voltage dividing and sampling unit and a differential signal processing unit;
- a first terminal of the temperature sensing voltage dividing and sampling unit is connectable to a second terminal of the temperature sensing conductor, a first terminal of the temperature sensing conductor is connectable to a live wire of the AC power supply, a second terminal of the temperature sensing voltage dividing and sampling unit is grounded, an output terminal of the temperature sensing voltage dividing and sampling unit is connected to the differential signal processing unit, and the temperature sensing voltage dividing and sampling unit is configured for converting a signal flowing through the temperature sensing conductor into a temperature voltage signal and output it to the differential signal processing unit;
- a first terminal of the AC voltage dividing and sampling unit is connected to the live wire of the AC power supply, a second terminal of the AC voltage dividing and sampling unit is grounded, an output terminal of the AC voltage dividing and sampling unit is connected to the differential signal processing unit, and the AC voltage dividing and sampling unit is configured for converting an input signal of the AC power supply into a reference voltage signal and output it to the differential signal processing unit;
- the differential signal processing unit is configured for performing a differential comparison between the temperature voltage signal and the reference voltage signal and outputting a stop-heating signal or a heating signal according to the differential comparison between the temperature voltage signal and the reference voltage signal;
- the heating switching circuit is connected to the temperature detecting circuit and is connectable to the heating conductor, and is configured for turning off a power supply circuit of the heating conductor when receiving the stop-heating signal, and turning on the power supply circuit of the heating conductor when receiving the heating signal, so as to control the heating conductor to heat or to stop heating;
- and
- the temperature parameter setting circuit is connected to the temperature detecting circuit for setting a temperature parameter.