JPS61116629A - Thermo-electric transducer circuit - Google Patents

Abstract

PURPOSE:To facilitate the measurement of temperature differences with time, by combining a quickly acting thermosensitive element and a variable resistance and a slowly acting thermosensitive element and a resistance to form a Wheatstone bridge, the quickly acting thermosensitive element of which is heated to obtain a voltage to which temperature differences are converted with time. CONSTITUTION:A thermo-electric transducer circuit is made up of a Wheatstone bridge in which a series array of a quickly acting element 1 and a variable resistance 4 is connected in parallel to a series array of a slowly acting thermosensitive 2+3 and a resistance 5, a variable resistance 6 for voltage adjustment, an npn-type transistor 7, a pnp-type transistor 8 and a voltage resistance 9. As the quickly acting thermosensitive element 1 is heated upon +t deg.C with an abnormal rise in the room temperature, a voltage DELTA converted from temperature differences with time is obtained. This voltage is amplified with the transistors 7 and 8 to obtain an output voltage DELTAE through the collector resistance 9 thereby facilitating the measurement of the temperature differences DELTAt with time.

Description

Detailed Description of the Invention (a) Field of Industrial Application The present invention relates to a thermoelectric conversion circuit for measuring temperature differences over time. In this method, a combination of a temperature needle and a recorder is used, and currently there is no simple thermoelectric conversion circuit for measuring temperature differences over time (see (1) fi).

(1) Semiconductor Ishikawa and circuits Figure 10 Figure 11 Figure 1
6th edition 1980 Seibundo Shinkosha Temperature-sensitive semiconductors in practice Chapter 8 Sanpo Publishing (c) Problems that the invention aims to solve For example, when an abnormal temperature rise occurs indoors, from that point on If it is necessary to measure the temperature rise difference +t°C after 60 seconds, a thermometer or recorder is currently required, and there is no easy method.

The present invention aims to obtain a thermoelectric conversion circuit that can easily measure the temperature rise difference +t°C between room temperature + t°C. As shown in Fig. 1, the thermoelectric conversion circuit for measuring the temperature rise difference t° C. in the middle is constructed by connecting a fast-acting thermosensitive element 1 and a variable resistor 4 in series, and a slow-acting thermosensitive element 2+3 and a resistor 5 in series. A Wheatstone electric bridge is constructed by connecting these components in parallel, and a circuit is constructed in which a DC power supply voltage E is applied to a composite circuit in which a variable resistor 6 for voltage adjustment is connected in series to the electric bridge, and a fast-acting thermosensitive element is constructed. By heating 1, a temporal temperature difference conversion voltage Δe can be obtained, and by adding this to the NPN transistor 7 to increase the width, the KPNP transistor 8 is further formed.
In addition, this book solves the problem by obtaining the thus obtained voltage drop ΔE in the collector resistor 9 as the output voltage.

Note that the fast-acting heat-sensitive element 1 and the slow-acting heat-sensitive element 2+3 are two heat-sensitive elements having the same temperature characteristics, and the slow-acting heat-sensitive element 2+3 is similar to the heat-sensitive element 2 using the heat insulating material 3. O (e) which is a heat insulated circuit.If the circuit of the present invention is balanced at room temperature by adjusting the variable resistor 4 and made into an increased width state, the normal room temperature will change gradually, so it will change over time. Temperature difference conversion voltage j.

key 0, therefore the output lE is 0. Now, the room temperature has risen abnormally, and the fast-acting thermosensitive element 1 is +t”C
When heated to , it becomes A@-+l@t in proportion to this, and becomes ノI 41 Et, but after a few minutes even at room temperature + t℃, it becomes j, middle 01 lEkiO. 0 This action is one of the features of the present invention, and is used to adjust the DC voltage to the variable resistor 6 Hiro Wheatstone Bridge.By adjusting this, the output j13 can be adjusted as shown in Figure 2. Increased temperature difference +t℃
The slope of the characteristic curve can be freely changed, which is a great advantage during point production.Figure 2 shows this characteristic.

(F) Embodiment The one shown in FIG. 3 is a temperature rise rate type fire detector obtained by combining the thermoelectric conversion circuit W of the present invention with a time limit circuit T.

(G) Effects of the Invention The circuit of the present invention enables the circuit setting of the amplified output jI3 of the temperature difference conversion voltage je over time, so it can be combined with a time-limited circuit like the fire detector shown in Fig. 3. The time Δ
It became possible to measure the temperature rise rate ΔE/At (without using a recorder) within Also, it is very sensitive and has almost no false alarms, so it is useful for fire prevention.

[Brief explanation of the drawing]

Figure 1 is a thermoelectric conversion circuit diagram of the present invention, Figure 2 is a variable resistor 6
Characteristic curve diagram of ΔE vs. +t°C that changes due to adjustment of , 3rd
The figure is a circuit diagram of a fire detector as an example of practical application. Variable resistance 5...
Resistor 6...Wheatstone bridge voltage adjustment variable resistor 7.
... NPN transistor 8 ... PNP transistor 9 ... Collector resistance + t'c ... Number of temperature increases from room temperature Δe ... Time-dependent temperature difference conversion voltage W ... Thermoelectric conversion of the present invention Circuit T...Time limit circuit (with switch) ΔE...Amplified output voltage of Δe E...DC power supply voltage

Claims (1)

[Claims] Fast-acting heat-sensitive element 1, variable resistor 4, and slow-acting heat-sensitive element 2
Build a Wheatstone electric bridge using +3 and resistor 5,
A variable resistor 6 for voltage adjustment is connected in series with the electric bridge, and an NPN type is used for detecting and amplifying the temporal temperature difference conversion voltage Δe obtained when the DC power supply voltage E is applied to the composite circuit. and P.N.
A thermoelectric conversion circuit characterized in that P-type transistors are connected in a complementary manner to obtain a voltage drop ΔE in a collector resistor 9 of a PNP-type transistor 8 as an output of a voltage converted from a temperature difference over time.