CS256060B1 - Electric heating coil with temperature sensor - Google Patents

Abstract

The electric heating coil with a temperature sensor in series connection is intended for heating elements with temperature control and with power supply and temperature sensing via two wires. The resistance spiral, which is the heat source of the heating element, is connected to the first thermocouple wire, which represents the heated part of the heating element, through which heat is transferred to the heated object. The second thermocouple wire is led out and is selected so that it has a different thermoelectric voltage relative to the wires of the heating spiral. With a suitable orientation of the supply voltage relative to the thermoelectric voltage, the thermoelectric voltage can be sensed on the outgoing wires and used to regulate the temperature of the heating element.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrical heating coil with a temperature sensor in series connection, in particular a heating coil of electric soldering irons with a temperature regulation of a soldering tip. In practice, there is a need to regulate the temperature of the electric heating coil, for example, for heating soldering tips of electric soldering irons. For this purpose, it is necessary to convert the temperature value into a suitable electrical potential. One of the possible ways of measuring the temperature of heating elements in practice is by measuring with metal thermocouples. If the heating coil and the thermocouple form two separate galvanically isolated circuits, we need to use two wires to power the heating coil and the other two conductors to sense the thermoelectric voltage.

The disadvantages of the described state are that separate thermocouple and heating coil terminals are required for the temperature measurement of the heating coil.

These drawbacks are eliminated by the electrical heating coil with a temperature sensor according to the invention, wherein the resistive coil is isolated wound on the surface of the first branch of the thermocouple, which also has the function of a support body, of an electrically conductive material at one end of which is a measurement link formed with the second branch of the thermocouple in the shape. a wire that simultaneously forms an outlet for the first terminal, one outlet of the resistance coil being connected to an inner connection formed at the other end of the first branch of the thermocouple and the other terminal of the resistive coil connected to the second terminal. Advantages of the heating coil with the temperature sensor according to the invention are in reducing the failure rate of the system, in saving material and in better handling of the heater. An exemplary embodiment of the invention is shown in the accompanying drawing, wherein the electric soldering iron heating coil is a thermocouple connected in series.

The electric temperature coil heating coil consists of a resistance coil 1 made of high temperature coefficient material and a large coil.

Claims (1)

SUBJECT Electrical heating coil with temperature sensor in series connection with two conductor supply and temperature sensing, consisting of a resistance coil and a thermocouple, characterized in that the resistive coil (1j is insulated wound on the surface of the first strand (2J thermocouple in the an electrically conductive material at one end of which is formed by a resistor which is insulated wound on the surface of the first branch 2 of the thermocouple This first branch 2 has the shape of a hollow support body of an electrically good conductive material and forms a thermocouple together with the second branch 3 The second branch 3 of the wire-shaped thermocouple simultaneously forms an outlet to the first terminal 6. One of the terminals of the resistance coil 1 is connected to the inner connections 4 formed at the other end of the first branch 2 of the carrier thermocouple. Second resistance spiral outlet 1 j The first terminal 6 and the second terminal 7 serve to connect the supply voltage as well as to sense the temperature of the support body forming the first branch 2 of the thermocouple. The first branch 2 of the thermocouple forming the heated portion of the electric solder heater body also has suitable thermal properties to ensure good heat transfer from the resistive coil 1 to the undrawn solder tip. The thermoelectric tension of the material from which the resistance coil 1 is made is different from the thermoelectric voltage of the thermocouple with the measurement link 5. By passing an electrical current from an unselected external source connected to terminals 6 and 7, heat is generated predominantly in the resistance coil 1. the branch 3 of the thermocouple which is connected in series with the resistive coil 1 is only slightly heated by the passage of the current because their resistance is much smaller than the resistance of the resistive coil 1. The heat of the resistance coil 1 heats the first branch 2 of the thermocouple. Thermoelectric stresses occur as a result of the temperature differences of the individual ends of the conductors on the inner joint 4 and the measuring joint 5. The resulting thermoelectric tension is determined by the sum of the thermoelectric stresses of the inner joint 4 and the measuring joint 5, and can be sensed at terminals 6 and 7 by a separate electronic circuit that provides temperature evaluation and controlled supply of the resistive coil. 5) with a second branch (3) of a thermocouple in the form of a wire, which simultaneously forms an outlet for the first terminal (6J, one outlet of the resistance coil (1j being connected to the inner joint (4J, formed at the second end of the first branch (2) of the thermocouple and the second the resistance spiral outlet (1) is directly connected to the second terminal (7) 1 sheet of drawings 256060