TEMPERATURE CONTROL DEVICE OF ELECTRIC HEATER USING THERMO-SENSITIVE RESIN AND SAFETY DEVICE THEREOF
First Claim
1. A temperature control device of an electric heater using a thermo-sensitive insulation resin, the temperature control device comprising:
- a heating wire, connected to an alternating current power source though a silicon controlled rectifier (SCR);
a sensing wire, disposed parallel to the heating wire;
a thermo-sensitive resin, configured to insulate the heating wire and the sensing wire from each other and change its impedance according to a change in temperature; and
a temperature sensing unit, configured to output a temperature control signal to turn the SCR on or off according to a change in electric current flowing through the thermo-sensitive resin, the SCR being turned on or off by a sensing unit diode,wherein the heating wire is heated by a heating current that flows in a heating cycle only, in which a forward voltage is formed in the SCR, by the SCR, and the sensing wire conducts a sensing current that flows in a sensing cycle only, in which a reverse voltage is formed in the SCR, by the sensing unit diode.
1 Assignment
0 Petitions
Accused Products
Abstract
A temperature control device is disclosed that includes a heating wire being connected to an alternating current power source though a SCR, a sensing wire being disposed parallel to the heating wire, a thermo-sensitive resin insulating the heating wire and the sensing wire from each other and changing its impedance according to a change in temperature, and a temperature sensing unit outputting a temperature control signal to turn the SCR on or off according to a change in electric current flowing through the thermo-sensitive resin, in which the SCR is turned on or off by a sensing unit diode. The heating wire is heated by a heating current that flows in a heating cycle only, in which a forward voltage is formed in the SCR, and the sensing wire conducts a sensing current that flows in a sensing cycle only, in which a reverse voltage is formed in the SCR.
15 Citations
20 Claims
-
1. A temperature control device of an electric heater using a thermo-sensitive insulation resin, the temperature control device comprising:
-
a heating wire, connected to an alternating current power source though a silicon controlled rectifier (SCR); a sensing wire, disposed parallel to the heating wire; a thermo-sensitive resin, configured to insulate the heating wire and the sensing wire from each other and change its impedance according to a change in temperature; and a temperature sensing unit, configured to output a temperature control signal to turn the SCR on or off according to a change in electric current flowing through the thermo-sensitive resin, the SCR being turned on or off by a sensing unit diode, wherein the heating wire is heated by a heating current that flows in a heating cycle only, in which a forward voltage is formed in the SCR, by the SCR, and the sensing wire conducts a sensing current that flows in a sensing cycle only, in which a reverse voltage is formed in the SCR, by the sensing unit diode. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
-
-
16. A temperature control device of an electric heater using a thermo-sensitive insulation resin, the temperature control device comprising:
-
a first heating terminal and a second heating terminal, respectively installed on either end of a heating wire; a sensing wire, disposed parallel to the heating wire, a first sensing terminal and a second sensing terminal respectively being connected to either end of the sensing wire; a thermo-sensitive resin, configured to insulate the heating wire and the sensing wire from each other and change its impedance according to a change in temperature; a silicon controlled rectifier (SCR), connected between one of the first and second heating terminals and an alternating current power source; a voltage sensing node, connected from ground through a first charging condenser to output a voltage to a first input terminal of a first comparator according to a change in temperature, the ground being connected to a second power terminal; a first sensing unit diode and a first sensing unit resistor, serially interposed between the voltage sensing node and the first sensing terminal and connected in a direction opposite to a forward voltage of the SCR; and a temperature sensing unit, configured to output a temperature control signal controlling the SCR to be turned on or off by the first comparator (U1), wherein the SCR is connected in a forward direction through the heating wire during each half cycle of the alternating current, the forward direction being a direction in which an electric current of the alternating current power source flows to the ground of the second power terminal, and the heating wire is heated by the electric current flowing through the first heating terminal→
the heating wire→
the second heating terminal→
the SCR→
the ground in a heating cycle, the heating cycle being a cycle in which a forward voltage is formed in the SCR,and wherein a voltage of the voltage sensing node is inputted into the first input terminal of the first comparator, the voltage of the voltage sensing node being charged into the first charging condenser by a sensing current that reversely flows in a sensing cycle through the ground→
the first charging condenser→
the voltage sensing node→
the first sensing unit resistor→
the first sensing unit diode→
the first sensing terminal→
the thermo-sensitive insulation resin→
the first heating terminal→
a first power terminal, the sensing cycle being a cycle in which a reverse voltage is formed in the SCR. - View Dependent Claims (17, 18, 19, 20)
-
Specification