JPS5839397A - Compensation type spot sensor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a compensated spot type sensor.
Conventional semiconductor sensors that do not use diaphragms or bimetals use two thermistors with different thermal responses connected in series to detect temperature rise and compare with a reference voltage, and another thermistor is used to detect constant temperature. I am using
Two thermistors with the same characteristics must be directly sensitive to the outside temperature, and the other Ill must be fixed at a predetermined position within the sensor to maintain proper sensing of the outside temperature.

In addition, the variation in the characteristics of the two thermistors used to detect the temperature rise has a large influence, so it was necessary to increase the accuracy of the characteristics. In view of this problem, we have reduced the number of thermistors, and created a compensation type socket that can absorb variations in the characteristics of the elements by adjusting the time constant using the discharge resistor and capacitor.
The purpose is to obtain a W sensor.

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the compensated spot type sensor of the present invention will be described with reference to the drawings.

In the figure, thermistors Th are connected in series.

A variable resistor V for capacitor discharge is installed at point a where the voltage is divided by a temperature sensing element such as a diode or transistor and a resistor.
A capacitor tC is connected in series with , and a resistor V
Connect diode D in parallel with B to promote charging of the capacitor and prevent backflow.

Voltage sensing element 1'U that compares the voltages at point 4ca and point b
Connect T l from point a to gate t, and from point ) to the anode. On the other hand, the voltage detection element PUT1 for each point a! % connected to the O gate, and connected to the 7th node from the middle point where two resistors are connected in series to this voltage sensing element PUT2.
Ru. These two voltage sensing elements PU'r1. Connect g to the switching element Nyris $80R.

Compare the voltages at point a and point 1 to determine the rate of temperature rise.
Detect constant temperature by comparing the points.

1 #1 fire receiver, capacitor t01 is for absorbing leakage current, noise 01 is for resistor, both switch style OWS *
It is for use.

Now, when the temperature rises rapidly, the voltage at rounded point a, where the resistance value of the thermistor T11 decreases flA sharply, also decreases rapidly. On the other hand, the voltage at the second point gradually decreases because -bhe is slowly discharged from the capacitor C1 through the resistor VB and the surcessor Th. When the temperature rises slowly, the voltages at point a, 'b, and ao all gradually decrease. Therefore, by appropriately selecting the value of the capacitor C2 and its resistance VR to determine the discharge time WLVr, it is possible to generate the necessary potential difference between points a and b depending on the rate of temperature rise. Therefore, by comparing points a and b, a circuit is created that switches thyristor 8 (3R) when the temperature rises above a certain rate.Also, by comparing point a and the fixed voltage point 0, it is determined that the temperature has become constant. When, thyristor 80
A circuit for switching R is created. Capacitor C! With this connection, a small amount of current will flow through the resistor vi' even after the capacitor is fully charged. Therefore, by selecting diode D with an appropriate resistance, a necessary potential difference can be generated between a and b. This has the effect of producing an initial stable potential difference between the anode of the voltage sensing element PUTl and the gate F.

Also, the voltage detection element may be a differential comparator other than PUT.
A temperature detection circuit in which a thermistor Th is connected in series with a resistor connected by a semiconductor integrated switching element such as a transistor in addition to a thyristor, a voltage dividing circuit consisting of two resistors R, , R, and a switching element. A charging/discharging circuit consisting of a variable resistor VB and a capacitor C is connected to both ends of the thermistor T11 of the temperature sensing circuit, and the temperature sensing element and the capacitor 0 terminal voltage are compared [detected]. , a temperature rise detection circuit including a voltage detection element PUTl that triggers the switching element 80R, a terminal voltage of the temperature sensing element, and a voltage dividing point voltage 1 of the voltage dividing circuit.
The compensating spot sensor consists of a constant temperature detection circuit consisting of a voltage detection element PUTg which triggers the switching signal 1t (jlR) by comparing and detecting the switching voltage. It is easy to produce because it does not require high precision parts such as the diameter and length of the holes, is resistant to corrosive gases, and eliminates malfunctions due to deformation of parts due to aging. As for the spring, the semiconductor type uses only one temperature sensing element, so variations in the characteristics of the temperature sensing element can be absorbed by adjusting the time constant using the discharge resistor R and capacitor C, making it possible to use a high precision temperature sensing element. In particular, since only one temperature sensing element is required, there is no need to differentiate the heat capacity as would be the case with two or eight, making it easier to adjust the sensitivity. Jintogadekura, which is performed with only one variable resistor,
It is convenient for manufacturing.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an embodiment of the present invention. E is the fire receiver, Th is the thermistor, hexa resistor, hexa capacitor, vR is the capacitor discharge resistor, PUTl, 2
is a voltage detection element, a resistor is a resistance, and an 8CR switching element

Claims (1)

[Claims] (1) Fire Receiver E A variable resistor VB and a capacitor T are provided at both ends of the thermistor Th of the temperature detection circuit.
C! A voltage detection element PUT which compares and detects the terminal voltages of the temperature sensing element and the capacitor to trigger the switching element 80B; Compensated type suboff) 8Ilffi detector 0 consisting of a constant temperature detection circuit consisting of a voltage detection element PUT2 that compares and detects the terminal voltage and the voltage division point voltage of the voltage division circuit and triggers the switching element 80K.