JPS6123260Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial field of use A hot water storage type electric water heater boils water using electricity late at night, keeps the hot water container warm, and uses the hot water during the day.

The present invention relates to a remaining hot water display circuit for these water heaters.

Conventional technology Figure 1 shows a conventional remaining hot water display circuit, in which G is a DC power supply, and T ₁ , T ₂ , and T ₃ are thermometers installed between the water inlet and the hot water outlet on the side of the hot water container. R ₁ , R ₂ , and R ₃ are resistors connected in series with the respective thermostats T ₁ , T ₂ , and T ₃ , and L is a coil of a remaining hot water amount display meter. The series circuits of the thermostat and the resistor are connected in parallel, and this parallel circuit and the coil L of the meter are connected in series to a DC power supply G. In this case, if all the hot water in the hot water container is at the specified temperature, the thermostat will
T ₁ , T ₂ , T ₃ are all in the on state, and at this time the resistances R ₁ , R ₂ ,
The combined resistance value of _R3 is determined.

Generally, the water inlet of a hot water container is located at the bottom, and the hot water outlet is located at the top, so water is replenished from the water inlet at the bottom according to the amount of hot water used, and the hot water in the hot water container is not directly separated from the water. Separated.
Therefore, if you start using hot water in this state, water will enter from the water inlet, and until the separation point between hot water and water passes through the installation position of thermostat _T1 , the fluctuation of the remaining hot water amount display meter will reach its maximum as shown in Figure 2. When passing the mounting position of thermostat T ₁ , thermostat T ₁ is turned off, and the meter deflection changes step by step to a point determined by the combined resistance value of resistors R ₂ and R ₃ . Similarly, as the separation point of hot water and water increases, the thermostat T ₂ ,
_T3 turns off one after another, and the meter's deflection gradually decreases from the maximum display.

Problems that the invention aims to solve: However, as shown above, the amount of remaining hot water is displayed in stages, and even if the amount of hot water decreases, the amount of remaining hot water remains constant until the point where hot water separates from cold water passes through the next stage thermostat. Furthermore, due to the response delay caused by the heat capacity of the thermostat, the display of the amount of remaining hot water does not change until the thermostat is turned off after a while after the separation point between hot water and cold water passes through the thermostat. etc., there was a problem that it did not correspond to the actual situation and was extremely inconvenient to use.

In addition, the technology disclosed in Utility Model Publication No. 50-31571 detects changes in temperature using a temperature-sensitive layer and drives a display meter according to the impedance change, but the impedance of the temperature-sensitive layer is high; There was a problem that the impedance change rate with respect to temperature was small, so it was difficult to notice it on the display meter.

Means for Solving the Problems The present invention amplifies changes in the current flowing through the temperature-sensitive layer using a transistor, drives a meter relay, and displays the amount of remaining hot water.

Effect With the above configuration, an amplified current flowing through the temperature sensitive layer flows through the meter relay.

The remaining hot water display circuit of the present invention can show the amount of remaining hot water in a continuous manner according to the amount, and can accurately grasp the amount of hot water actually remaining in the hot water container, making it easier to use. be.

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Figure 4 shows an example of the remaining hot water display circuit of the present invention. In the figure, 6 is a temperature sensing element installed between the water inlet on the bottom side of the hot water container and the hot water outlet at the top.
Two electrodes 2 and 4 are provided so as to face each other with a temperature-sensitive layer 3 having a negative characteristic interposed therebetween. R ₄ is a resistance element A that determines the base potential of the transistor Q ₁ and is connected in series with the temperature sensing element 6 . transistor
_Q1 has a meter coil L for displaying the remaining hot water connected to its collector, and a resistance element B of _R5 , which determines the current flowing through the meter coil L, to its emitter.
The respective series circuits mentioned above are connected in parallel so that the temperature sensor 6 becomes the collector of the transistor _Q1 , and the connection midpoint between the temperature sensor 6 and the resistance element A of _R4 is connected to the base of the transistor _Q1 . A DC power supply G is connected to both ends of the parallel circuit. Figure 5 is a configuration diagram of the temperature sensing element 6 used in this remaining hot water display circuit, in which 1 is a core thread of polyester, etc., 2 and 4 are electrode wires, and 3 is a negative characteristic whose resistance changes depending on the temperature. The temperature-sensitive layer 5 is an insulating jacket made of polyvinyl chloride or the like, and 2, 3, and 4 in FIG. 4 are the electrode wires 2, 5 in FIG.
4. Corresponding to the temperature sensitive layer 3, the electrode wires 2 and 4 may be connected to either the connection point A or B in FIG. FIG. 6 is a state diagram in which the temperature sensor 6 is attached to a hot water container, where 7 is a hot water container, 8 is a water inlet, and 9 is a hot water container.
1 is a hot water outlet, and 10 is a lead wire connecting to connection points A and B in FIG. At this time, the fluctuation of the remaining hot water amount display meter, that is, the current I flowing through the meter coil L
_L is calculated using the following formula.

I _L = (E・R ₄ /RT _h +R ₄ −V _BE )/R ₅ ......
I _L : Current flowing through meter coil L E: Voltage of DC power supply G RT _h : Resistance of temperature sensing element 6 V _BE : Base-emitter voltage of transistor _Q1 Voltage E of DC power supply G, base-emitter voltage of transistor _Q1 Once the voltage V _BE , the resistance value RT _h of the temperature sensor 6, and the thermistor B constant are determined, first, when all the water is in the hot water container 7 (when the resistance value RT _h of the temperature sensor 6 is large RT _hp ) The value of the resistance element A of R ₄ is determined by the formula so that the meter deflection is zero (I _L =0).

E・R ₄ / (RT _hp + R ₄ ) = V _BE ... Next, when all the water in the hot water container 7 is at the specified temperature (when the resistance value RT _h of the temperature sensor 6 is small RT _hn ) The value of the resistive element B of _R5 is determined according to the above formula so that the meter deflection becomes maximum I _Ln .

I _Ln = (E・R ₄ /RT _hn +R ₄ -V _BE )/R ₅ ...
... When you start using hot water after all the water in the hot water container 7 has reached the predetermined temperature, the separation point between the water that entered the hot water container 7 from the water supply port 8 and the hot water in the hot water container 7 increases. , the meter does not move until the temperature sensor 6 is attached, and when the separation point enters the area where the temperature sensor 6 is attached, the meter deflection decreases accordingly. For example, when the separation point comes to 1/4 from the bottom of the temperature sensor 6, the lower 1/4 of the temperature sensor 6 has the water temperature resistance value RT _h1 , and the remaining 3/4 has the water temperature. Therefore, the combined resistance value RT _{h ′} of the temperature sensing element 5 becomes large as RT _h ′ = (1/1/RT _h1 + 1/RT _h2 < RT _hn , which can be seen from the formula In this way, as hot water begins to be used and the separation point between the hot water and the hot water moves from the bottom to the top of the temperature sensor 6, the meter swing corresponds to the amount of hot water remaining in the hot water container 7. It becomes smaller continuously, making it extremely convenient to use.Also, compared to mechanical temperature detection methods such as thermostats, this type of temperature sensor can structurally reduce its heat capacity. The responsiveness due to the movement of the separation point between water and hot water is extremely good as shown in FIG.

7 to 11 show other embodiments of the remaining hot water display circuit of the present invention.

In FIG. 7, the same numbers as in FIG. 4 represent the same parts, and a diode D having the same polarity as the transistor _Q1 is connected in series with the resistance element A of _R4 . The basic operation of this circuit is the same as that shown in FIG. Base-emitter voltage V _B of transistor Q _1
E fluctuates due to changes in ambient temperature, and as can be seen from the above equation, the meter swing changes. Diode D is used to prevent this. For example, if the ambient temperature changes, the transistor
When the base-emitter voltage V _BE of Q ₁ increases, the forward voltage drop of diode D also increases in proportion, and the voltage across diode D and resistor R ₄ increases. In other words, the voltage across the series circuit of the base-emitter of transistor Q ₁ and resistor R ₅ also increases, and the voltage obtained by subtracting the base-emitter voltage V _BE of the transistor from this voltage, that is,
The voltage across resistive element B of _R5 does not change, and the current flowing through meter coil L, that is, the meter deflection, does not change.

Figure 8 shows a variable resistor VR connected in series with resistance element A of _R4 .
The basic operation is the same as that shown in Fig. 4. Since there are variations in the base-emitter voltage V _BE of the temperature sensor 6, resistors R ₄ and R ₅ , and transistor Q ₁ , if these are left as they are, the meter swing will change depending on the remaining water display circuit. It ends up. Therefore, by adjusting the variable resistor VR, the voltage applied to the base-emitter of the transistor _Q1 and the series circuit of the resistor _R5 is adjusted, and the current flowing through the meter coil L is adjusted, so that when all the water in the hot water container 7 is hot, the meter The maximum runout is kept constant.

Figure 9 shows a variable resistor VR in series with resistance element B of _R5 .
are connected, and the basic operation is the same as that in FIG. Similar to Figure 8, this circuit is also used to adjust the fluctuation of the meter due to variations in each circuit component, and is connected to a variable resistor VR.
is adjusted so that the maximum deflection of the meter remains constant when all of the water in the hot water container 7 is hot.

In Fig. 10, a diode D and a variable resistor VR having the same polarity as the transistor _Q1 are connected in series with the resistance element A of _R4 , and its basic operation is the same as that in Fig. 4. This circuit has the effects of both the circuits shown in FIGS.

FIG. 11 shows a circuit in which a diode D is connected in series with a resistor element A of _R4 so that it has the same polarity as the transistor _Q1 , and a variable resistor VR is connected in series with a resistor element B of _R5 . The basic operation of this circuit is the same as that of FIG. 4, and it combines the effects of both the circuits of FIG. 7 and FIG. 9.

FIGS. 12 and 13 show other configuration examples of the temperature sensitive body 6. FIG.

In FIG. 12, 11 is a flat substrate made of polyester or the like, 12 is two electrodes, and 13 is a temperature-sensitive coating film, which is attached to the hot water container 7 as shown in FIG. A similar effect can be obtained by connecting to points A and B in the figure.

In FIG. 13, 14 is an insulating layer made of polyester, polyvinyl chloride, etc., 15 is a sheet-like electrode made of copper, etc., 16 is a terminal of the two electrodes 15, and 17 is a temperature-sensitive layer. It is similar to that in the figure.

Figure 14 shows the NPN type transistor shown in Figure 4.
It goes without saying that this is a remaining water display circuit using a PNP type transistor _Q2 in place of _Q1 , and its operation is the same as that shown in FIG.

Effects of the invention As is clear from the above, according to the invention, the current flowing through the temperature sensing element is amplified by the transistor, and then the current flows through the meter coil, so the amount of remaining hot water can be continuously and accurately measured. This means that it can be displayed.

[Brief explanation of the drawing]

Fig. 1 is a diagram of a conventional remaining hot water display circuit, Fig. 2 is a diagram showing the relationship between the amount of remaining hot water and meter fluctuation in a conventional remaining hot water indicating circuit, and Fig. 3 is a diagram showing the amount of remaining hot water in the remaining hot water display circuit of the present invention. FIG. 4 is a diagram showing a remaining hot water display circuit in an embodiment of the present invention.
Fig. 5 is a diagram showing the structure of the temperature sensor of the remaining hot water display circuit according to the present invention, Fig. 6 is a diagram showing how the temperature sensor of the remaining hot water display circuit according to the present invention is attached to the hot water container, and Fig. 7 11 and 14 are circuit diagrams showing other embodiments of the remaining hot water display circuit of the present invention, and FIG.
13 are diagrams showing the structure of another temperature sensor used in the remaining hot water display circuit according to the present invention. 2, 4... Electrode wire, 3... Temperature sensitive layer with negative temperature resistance characteristics, 5... Insulating jacket, 6... Temperature sensitive body,
7...Hot water container, 8...Water inlet, 9...Hot water outlet, _R4 ...Resistance element A, _R5 ...Resistance element B, D
...Diode, VR...variable resistor.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A temperature sensing element in which two electrodes face each other via a temperature sensing layer having negative temperature resistance characteristics is disposed between the water inlet and the hot water outlet of a hot water container. The temperature sensitive body and resistance element A are connected in series to form a series circuit, and the midpoint of the connection is connected to the base of the transistor, and the emitter of the transistor is connected to resistance element B, and the collector is connected to the meter coil. are connected to each other to form a series circuit, these two series circuits are connected in parallel so that the temperature sensing element is on the collector side of the transistor, and a DC power source is connected to both ends of the parallel circuit with the series circuit. Remaining hot water display circuit. (2) The remaining hot water display circuit according to claim 1 of the utility model registration, which comprises a resistive element A and a diode connected in series with the resistive element A so as to have the same polarity as the transistor. (3) The remaining hot water display circuit according to claim 1 of the utility model registration claim, which comprises a resistive element A and a variable resistor connected in series with the resistive element A. (4) The remaining hot water display circuit according to claim 1 of the utility model registration claim, which comprises a variable resistor connected in series with resistance element B. (5) The remaining hot water display circuit according to claim 2 of the utility model registration, which is formed by connecting a variable resistor in series to any part of a series circuit of a diode and a resistive element A. (6) The remaining hot water display circuit according to claim 4 of the utility model registration, which comprises a variable resistor connected in series with resistance element B, and a diode connected to resistance element A.