JPS5937770B2 - temperature detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention combines a heat-sensitive thyristor that senses temperature and switches, and a thyristor whose resistance value changes depending on temperature.
It relates to a temperature detection device that is enclosed in a metal case, and in particular utilizes the resistance-temperature characteristics of the thermistor to display continuous temperature changes with a thermometer connected in series to the thermistor. The present invention relates to a temperature detection device that utilizes temperature switching characteristics to notify that a predetermined temperature has been reached by lighting up a display element connected in series to a heat-sensitive thermistor.

A temperature detection circuit has been proposed that uses the resistance-temperature characteristics of a thermistor to display continuous temperature changes, and uses the temperature switching characteristics of a heat-sensitive thyristor to notify that a predetermined temperature has been reached.

FIG. 1 is a circuit diagram showing the temperature detection circuit. In the figure, 1 is a thermistor, 2 is an ammeter, 3 is a capacitor, 5 is a heat-sensitive thyristor, 6 is a capacitor, 1 is a resistor,
8 is a lamp, 9 is a condenser, and 10 is a switch. In such a configuration, when the temperature of the thermistor 1 increases, the resistance of the thermistor 1 decreases, and if the voltage of the capacitor 3 is constant, the current flowing through the ammeter 2 increases.

In other words, since the temperature of thermistor 1 can be determined from the current value,
If a temperature scale is attached to the scale of the ammeter 2's instrument panel instead of the current value, the ammeter 2 becomes a thermometer. Next, the switching temperature of the heat-sensitive thyristor 5 can be changed (adjusted) by appropriately selecting the value of the resistor 7 inserted between the gate and the cathode.

For example, if we assume that the value of the resistor T is selected appropriately and the thermal thyristor 5 switches when the voltage of the capacitor 9 reaches 12 V and the temperature reaches 50°C, a lamp 8 and a switch 10 are inserted between the thermal thyristor 5 and the capacitor 9 to form a closed circuit. When the heat-sensitive thyristor 5 is heated to 50°C or higher, the heat-sensitive thyristor 5
switches at a point of 50°C, current flows, and lamp 8
is lit, and by lighting the lamp 8, it can be known that the temperature of the heat-sensitive thyristor 5 has reached 50°C. That is, if the thermistor 1 and the heat-sensitive thyristor 5 are located at the same position, the ammeter 2 will measure the ever-changing temperatures of the thermistor 1 and the heat-sensitive thyristor 5 (i.e., if the thermistor 1 and the heat-sensitive thyristor 5 are placed at the same position) At the same time, it is possible to know by lighting the lamp 8 when the temperature has reached exactly 50°C. The role of the capacitor 6 is to prevent sudden or unexpected noise or surge voltage from being applied to the heat-sensitive thyristor 5.
The purpose is to protect the heat-sensitive thyristor 5 by absorbing these noises and surge voltages so that the heat-sensitive thyristor 5 does not malfunction.

Now, in order to put into practical use a temperature detection circuit that detects the temperature of an object (solid, liquid, or gas) using a thermistor and a heat-sensitive thyristor that change their electrical characteristics in response to temperature, we need to It is important that the temperature detection section 4, which is surrounded by a broken line in FIG. 1, be able to accurately and quickly detect the temperature of the same object.

Therefore, in this invention, the thermistor and the heat-sensitive thyristor are
We provide a new temperature detection device that can detect the temperature of the same object with good thermal response by enclosing a thermistor and a heat-sensitive thyristor in a single metal case. The purpose is to

In order to achieve such an object, the present invention Iζ includes a metal container, a plate-shaped thermistor that is placed on the bottom of the metal container with one electrode in contact with the metal container, and whose resistance changes depending on temperature; An electrode plate placed on the thermistor so as to be in contact with the other electrode of the thermistor, and an electrode plate placed on the electrode plate in an electrically insulated manner and having a gate terminal connected to the metal container via a resistor. A heat-sensitive thyristor with a capacitor connected between an anode terminal and a cathode terminal that senses the temperature and switches, a spring that presses the laminate consisting of the thermistor, an electrode plate, and the heat-sensitive thyristor, and a cathode of the heat-sensitive thyristor that receives the pressure of this spring. A metal plate electrically connects the terminal and the gate terminal to the metal container, and an insulated conductor wire insulates and electrically leads out the electrode plate and the anode terminal of the heat-sensitive thyristor from the metal container. It is something.

Hereinafter, the present invention will be explained in detail using a specific example.

FIG. 2 is a sectional view showing an embodiment of a temperature sensing device according to the invention suitable for measuring the temperature of a liquid.

In FIG. 2, terminal 29 and terminal 30 are each connected to the first
Corresponds to terminals A and B in the figure.

A case 11 made of brass constitutes the ground terminal shown in FIG. In order from the bottom of the brass case 11, there is a plate-shaped thermistor 1, a metal plate 12 that serves as one electrode terminal of this thermistor 1, a resin-sealed heat-sensitive thyristor 5, and an insulating plate that can withstand the force of the next spring spring. 13, Spring spring 14, Thick metal plate, 15, Rubber O-ring 16,
and an insulating plate 17, and place the insulating plate 17 on the brass case 1.
1 and fix the insulating plate 17 by bending the ear 111 of the brass case 11. Therefore, the thermistor 1 is pressed against the bottom of the brass case 11 by the pressure of the spring spring 14, and the heat-sensitive thyristor 5 is also pressed against the metal plate 12 by the pressure of the spring spring 14. . If this water temperature detection device is attached to a container wall 18 and immersed in a liquid 31 at a temperature of T° C. surrounded by another container wall 19 as shown in FIG. 2, the thermistor 1, metal plate 12 and thermosensitive Since the thyristor 5 is held down by the spring spring 14, the liquid temperature T
℃ is easily transmitted to the thermistor 1 and the heat-sensitive thyristor 5. One terminal of thermistor 1 is connected to brass case 1.
Since the case 11 is in contact with the bottom of the case 11, it is grounded by connecting the case 11 to the ground.

The other terminal of the thermistor 1 is in contact with the metal plate 12 and has a covered conductor 20 that passes through the insulating plate 13 and the metal plate 15.
It is connected to terminal 29 by. 21 is an insulating coating part.

The anode terminal 25 of the heat-sensitive thyristor 5 is connected to a terminal 30 by a conductive wire 32 covered with an insulation coating 23 and passing through the insulating plate 13 and the metal plate 15.

The cathode terminal 2211 of the heat-sensitive thyristor 5 is connected to one terminal 26 of the capacitor 6 by an insulated conductor 24 passing through the insulating plate 13, and the one terminal 26 of the capacitor 6 is soldered to the metal plate 15. Or spot welded. The other terminal 34 of this capacitor 6 is connected to a conducting wire 32. The metal plate 15 is the brass case 11
Since it is in contact with the metal plate 15, it is the same as the ground.
The = terminal of a resistor 7 is connected to the gate electrode 27 of the heat-sensitive thyristor 5, and the other terminal of this resistor 7 is connected to the capacitor 6.
is connected to the terminal 26 of.

In this way, the circuit of the temperature detection section 4 shown in FIG. 1 is completed.
28 is a resin for fixing the terminals 29 and 30.

The insulating ring 33 between the thermistor 1, the metal plate 12, the heat-sensitive thyristor 5, and the inner wall of the brass case 11 serves to prevent the thermistor 1 from shifting and contacting the inner wall of the brass case 11, and to prevent the thermistor 1 from coming into contact with the inner wall of the brass case 11. Heat sensitive thyristor 5
It works to prevent the material from shifting significantly. In such a device for detecting the temperature of a liquid or gas, the thermistor 1 and the heat-sensitive thyristor 5 are enclosed in a brass case 11 so that all or most of them are covered by the gas or liquid. That is also important.

As described above, according to the present invention, a thermistor and a heat-sensitive thyristor are used, and the thermistor and heat-sensitive thyristor are enclosed in one metal case, and the temperature of the same object can be detected with good thermal response. The device is easily available.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing →l of a temperature detection circuit using the device of this invention, and FIG. 2 is a sectional view showing one embodiment of the invention. In the figure, 1 is a thermistor, 5 is a heat-sensitive thyristor, and 6
is a capacitor, 7 is a resistor, 8 is a lamp, 11 is a brass case, 12 is a metal plate, 13 is an insulating plate, 14 is a spring spring, 15 is a metal plate, 16 is an O-ring, 17 is an insulating plate, 2
0, 24 and 32 are insulated conductor wires, 22 is a cathode terminal,
25 is an anode terminal, 27 is a gate terminal, 29 and 30 are terminals, and 33 is an insulating ring.

Claims (1)

[Claims] 1 Using the resistance-temperature characteristics of the thermistor to display continuous temperature changes with a thermometer connected in series to the thermistor,
In a temperature detection device that utilizes the temperature switching characteristics of a heat-sensitive thyristor to notify that a predetermined temperature has been reached by lighting up a display element connected in series to the heat-sensitive thyristor, one electrode is in contact with the metal container. a plate-shaped thermistor that is placed on the bottom of the metal container and whose resistance value changes depending on temperature; and an electrode plate that is placed on the thermistor so as to be in contact with the other electrode of the thermistor. a heat-sensitive thyristor that is electrically insulated and placed on the electrode plate, has a gate terminal connected to the metal container via a resistor, has a capacitor connected between the anode terminal and the cathode terminal, and switches in response to temperature; a spring that presses the laminate consisting of the thermistor, an electrode plate, and a heat-sensitive thyristor; a metal plate that receives the pressure of the spring and electrically connects the cathode terminal and gate terminal of the heat-sensitive thyristor to the metal container; and the electrode plate. and an insulated conductor wire that insulates and electrically leads out the anode terminal of the heat-sensitive thyristor from the metal container.