JPH0116172Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a temperature control device for electric heaters such as electric blankets, electric bed blankets, electric lap blankets, electric carpets, electric cushions, electric cushions, etc., and particularly relates to a security device for the temperature control device. .

An embodiment of the temperature control device of the present invention will be described in detail below with reference to the drawings.

In the drawing, 1 is an AC power supply, 2 is one conductor of the heating element, that is, a heating wire, 3 is the other conductor of the heating element, that is, a signal line, and 4 is an insulator when the heating element is normal, but becomes a conductor when it overheats. 5 is a first diode, 6 is a second diode, 7 is a heating resistor, 8 is a controlled rectifier element (hereinafter referred to as a thyristor),
9 is a temperature fuse.

In this drawing, parts, circuits (means), etc. that are not directly related to the present invention, such as heat sensitive means and thyristor control means, are omitted.

A series circuit of a heating wire 2, a first diode 5, a thyristor 8 having the same polarity as the first diode 5, and a temperature fuse 9 are connected to the AC power supply 1 to form a main circuit. At least one of the signal lines is connected to the connecting end of the first diode 5 and the thyristor 8, and further a series circuit of a second diode 6 and a resistor 7 having a polarity opposite to that of the thyristor 8 is connected in parallel to both ends of the thyristor. The heating line 2, the signal line 3, the melting layer 4, and the first diode 5 are provided in the heater body, and the second diode 6,
Heat generating resistor 7, control rectifier 8, temperature fuse 9
is provided on the control section, which is the operation section.

In the above temperature control device, under normal conditions, the heating element maintains a normal temperature by the operation of the thyristor 8, but if the heating element becomes overheated due to some reason and the melted layer 4 becomes melted, the heating wire 2 and The signal line 3 becomes short-circuited (low impedance).

The short circuit current then flows through the next closed circuit during the negative half cycle of the AC power supply (when the thyristor has reverse polarity).

That is, a short circuit current flows through a closed circuit consisting of AC power supply 1 - temperature fuse 9 - resistor 7 - second diode 6 - signal line 3 - melting layer 4 - heating wire 2 - AC power supply 1, causing resistor 7 to generate heat.

Note that when the heating element is normal, the impedance of the dissolving layer 4 is high and the resistor 7 does not generate heat.

Then, the temperature fuse 9, which is mounted near the resistor 7, is indirectly heated and blown, thereby ensuring the safety of the equipment.

Since the temperature control device of the present invention has the above-mentioned configuration, when it overheats, the melted layer melts and energizes the resistor, and the heat generated by the resistor melts the temperature fuse and cuts off the energization to the heating element, which is dangerous. to prevent
It is possible to provide an inexpensive temperature control device that reliably prevents temperature with a simple configuration, and is particularly suitable for use in electric carpets, electric blankets, etc., by providing a heating element in the main body and a first diode in the main circuit, A control rectifier, a second diode, a resistor, and a temperature fuse can be provided in the control section, which simplifies the structure of the main body and reduces the number of connecting wires between the main body and the control to a minimum of two. This allows the connection work to be performed extremely easily and quickly.

[Brief explanation of the drawing]

The drawing is a schematic circuit diagram showing an embodiment of the temperature control device of the present invention. In the drawing, 2 is a heating line, 3 is a signal line, 4 is a dissolving layer, 5 and 6 are diodes, 7 is a heating resistor, 8 is a control rectifier, and 9 is a temperature fuse.

Claims (1)

[Scope of Claim for Utility Model Registration] At least one of the pair of conductors wound through a melting layer that is an insulator when the heating element provided in the main body of the heater is normal and becomes a conductor when it overheats is a heating wire ( In a temperature control device for an electric heater configured to control the current of the heating wire of a heating element used as a load by a control rectifier, the heating wire, a first diode, and the first diode are connected to each other. A main circuit is formed by connecting a controlled rectifying element and a temperature fuse in series with the same polarity, and at least one end of the other conductor of the heating element is connected to the connection end of the controlled rectifying element of the first diode of the main circuit. and a series circuit of a second diode having a polarity opposite to that of the control rectifier and a heat generating resistor that heats and blows the temperature fuse in the event of abnormal operation is connected to the control rectifier in parallel, and the heater body The heating element and the first diode are provided in the heater body, and the control rectifying element, the temperature fuse, the second diode, and the heat generating resistor are provided in the control section connected to the heater main body. Heater temperature control device.