JPH10225245A - Warmer for water in water tank - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a safer entitled appliance capable of preventing the change of water temperature caused by the breakage and the destruction of a heater, etc., and preventing an accident resulting in injury or death caused by a short circuit, a fire, etc., by detect and storing a current at the time of feeding power and control-stopping power feeding to the heater with respect to the optical change of the current by the value. SOLUTION: This appliance warms and heats water in a water tank by feeding power to the heater A from a commercial power source B. In the case, a power feeding control stopping circuit C providing a current detector (p) detecting a current flowing to the heater A for a power feeding circuit and provided with a power feeding interruption device (e) measuring the change of a current value, detecting the fixed change of the current value and control- stopping power feeding to the heater A, a current at the time of feeding power such as a rush current value, the current value after the lapse of a fixed time e.g. is detected by the detector (p) and stored in a computer unit (y) through an analog/digital converter (x) by way of an amplifier (q) to control-stop power feeding to the heater A with respect to the optional change of the current from the value.

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the field of instruments for keeping tank water and circulating water warm.

[0002]

2. Description of the Related Art Japanese Patent Application No. 8-278535 discloses a heater device using a heating element whose resistance value changes with temperature, in which a current flowing through the heater is detected by a current detector and the power is cut off based on the change. . In this apparatus, when the resistance value of the heating element for each product is non-uniform, when the power supply is stopped at the same current value, the power supply stop surface temperature varies from product to product.

[0003]

SUMMARY OF THE INVENTION In a device for detecting a current with a conventional current detector and stopping power supply to a heater at a specified current value, each individual resistance value is measured, and a current matching the resistance value is detected. If a circuit for stopping power supply is added, safe control at the heater surface temperature is possible. However, determine the resistance value of each heater, inspect the specified current value at which power supply to each heater is stopped at a safe surface temperature,
Producing the power supply control stop circuits individually has problems in terms of mass production and cost.

Japanese Patent Application Laid-Open No. 8-172977 discloses a commercially available fine ceramic heater using tungsten as a heating element for ornamental fish. Approximately ± 10% when 30Ω is used as a reference.
Therefore, even if the power supply stop current value is determined by the power supply stop circuit using individual heating elements, the power supply stop temperature for each product will vary, and some products will have a high heater power supply stop surface temperature setting product. , Part of the heater from underwater,
Or, when the whole was exposed, even if it did not lead to fire, it touched the water, and the heater was destroyed by the thermal shock.

[0005]

The object of the present invention is to provide an aquarium water warming device which has been developed in view of the problems of the prior art. By providing a safer product that detects the current value that can become the temperature and stops the power supply to the heater, preventing the water temperature from dropping due to the breakage or destruction of the heater, and preventing human injury due to electric leakage or fire. Aim.

[0006]

In order to achieve the above object, a water tank water warming device according to the present invention is provided with a device for detecting and storing a current value when power is supplied from a power supply circuit to a heater, and a device for detecting and storing a current value based on the value. When a change in the current value is recognized, that is, when the specified surface temperature is reached, the power supply to the heater is stopped.

[0007]

With the above arrangement, even if the same power supply control stop circuit is used for heaters having different resistance values, the temperature does not rise to an arbitrary heater surface temperature or higher. As a result, even if the heater is exposed from the water and power is supplied to the heater, an arbitrary power supply stop temperature is set, and if a current that can be judged to have reached the temperature flows through the heater, power supply stops and an accident occurs. It does not occur.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing an embodiment of an aquarium water warming device according to the present invention. FIG. 1 is a view showing an embodiment of an aquarium water warming device according to the present invention, in which A is a heater, B is a commercial power supply, and C is a circuit for controlling and stopping power supply to the heater. Power supply to the heater is started directly from a commercial power supply or via a circuit such as a temperature controller or a timer. The rush current at that time and the current after a certain period of time are detected by a current detector p such as a shunt, and are stored in a computer unit (CPU) y via an analog / digital (A / D) converter x via an amplifier q. The current detector p detects an arbitrary current change from the stored current value, the CPU recognizes the current change, and issues a command to stop the power supply to the semiconductor relay e such as the SSR.

FIG. 2 shows that control by a relay t instead of a semiconductor relay is also possible. In this way, any form can be used as long as it recognizes the inrush current to the heater and the current after a certain period of time, detects the current change of an arbitrary value with respect to that value, and then stops the power supply. Any one may be used.

[0010] Further, the CPU resumes power supply after water supply control due to water temperature control or heater resistance change, for example, a mechanism for starting energization when the resistance value change returns from an abnormal value, or a power supply control provided with a timer function by providing a timer function. After an elapse of an arbitrary time from the stop, any function such as returning the power supply to a normal state can be added.

The inrush current of a commercially available fine ceramic heater at the start of energization is 90 V in water at 25 ° C., 3.0 V
A was recorded, but the steady-state current value was about 2.6A.
In the case where the inrush current was 110 V and 4.0 A, it was about 3.4 A. Thus, a value obtained by subtracting about 0.4 and 0.6 A from the rush current value of a commercially available heater is the current value flowing through the heater. The temperature of the heater heating element at that time indicates a temperature higher than the surface temperature.
As a result, the inrush current was measured, and the
It is possible to estimate the resistance value at about the water temperature. The heater surface temperature in water at the time of power supply was about 100 ° C. for all products.

If the heater is exposed to the air and the power supply is stopped at a current value of 0.9 A below the inrush current, the heater surface temperature at that time is about 155 ° C., the resistance value is about 41Ω, and the heating element The linear temperature was around 160 ° C. Similarly, when the control was stopped, the heater surface temperature was about 150 ° C., the resistance value was 35.5Ω, and the heating element wire temperature was about 155 ° C. From this, 33Ω ±
For a product of about 10%, the inrush current is measured by a current detector, and a value obtained by subtracting 0.9 A from the value is set as a power supply control stop current value, and a device for storing the inrush current in a power supply cutoff portion is added. When the current value drops by a specified value from that value, if the power supply to the heater is stopped, even if the resistance value of the heater fluctuates by about ± 10%, the rough power supply control stop surface temperature is indirectly detected. However, the power supply control can be stopped with relatively high accuracy.

The inrush current value of a product of about 66 Ω in a 25 ° C., underwater energized state produced by the same production method having a significantly different resistance value is 100 V, about 1.8 A, and a steady current value of about 1.5 A. there were. The current value at a surface temperature of 150 ° C. was about 1.3 A, the resistance value was 79Ω, and the heating element wire temperature was about 160 ° C. For this reason, if a heater with a resistance value of one of these or a resistor with a different resistance value manufactured according to its specifications was randomly selected and connected to the power supply control stop circuit, the inrush current flowed to the current detector. The value is measured, and if the inrush current value is roughly 1.5 to 2.4 A, 0.71
If the multiplied value is 2.4 to 2.9 A, the value multiplied by 0.72 is 3.0 to 3.4, and if the multiplied value is 0.73, the value multiplied by 0.73 is 3.5 to 3.8 A. If the value multiplied by 0.75 is 3.9
If it is embedded in the CPU so that the value obtained by multiplying by 0.80 is the power supply control stop current value if it is up to 4.1 A, the power supply control of the heater having a resistance value of about 30 Ω to 70 Ω which is used this time in the energized state at a water temperature of 25 ° C. The stop surface temperature can be set to about 160 ° C. or less.

Next, an embodiment of a method of detecting and storing a current value after a predetermined time and stopping the power supply control will be described. In a 25 ° C water heater, the inrush current is stable and the steady current is 2.6A.
It takes about 1.3 seconds to stabilize,
In the case of (1), the time required to stabilize to a steady current of 3.4 A was about 1.7 seconds, and in the case of (1), the time required to stabilize to a steady current value of 1.5 A was within 1 second.

As a result of examining the time required for several tens of commercially available fine ceramic heaters to be stabilized from a power supply at a voltage of about 90 V to 110 V until a steady current is obtained,
The longest one is about 2.6 seconds, and if the resistance value is larger than that of a commercially available product, the time required to stabilize to a steady current will be shorter than 2.6 seconds.

As described above, if the resistance value of the commercial product is higher than that of the commercial product, the current value after 2.6 seconds is detected and stored, so that the heater having the resistance value within the range is detected. It is possible to grasp the steady-state current value in the water, and when an arbitrary value changes from the current value, the power supply to the heater may be stopped.

The constant current value of the heater in water at 90 V and 25 ° C. is 2.6 A, and the surface temperature of the heater at that time is 99 ° C.
Met. When this heater is exposed to the air, the current flowing within 1 second drops to about 2.3 A or less and the surface temperature becomes 1
It was about 40 ° C. The steady-state current value of the heater in 110 V water at 25 ° C. was 3.4 A, and the heater surface temperature at that time was about 100 ° C. When this heater is exposed to the air, the current flowing within 1 second is less than 3.1 A and 150
° C. The constant current value of the heater in water at 100 V and 25 ° C. is 1.5 A.
It was about 9 ° C. When this heater is exposed to the air, the current flowing in about one second is 1.2 A or less and the surface temperature is 160
° C. In addition, each voltage of
When the voltage is 0 V, the steady-state current values are about 2.9 A and 3.1 A, and the surface temperature of the current value 0.3 A lower than the values is 145 ° C. and 1
It was about 60 ° C. As a result, the surface temperature is raised to about 160 ° C. or more in the case of the above-mentioned specification if the steady-state current in the water is detected and stored, and a value equal to or less than 0.3 A lower than that value is set as the power supply control stop current value. Never.

As described above, by detecting and storing the stable steady-state current in water, if the power supply is stopped at an arbitrary value according to a certain rule according to a certain rule, the surface temperature of a plurality of heaters can be adjusted to an arbitrary temperature in the same circuit. No more rise.

The heater A may be in any form as long as the resistance of the heating element changes with temperature change. The resistance change characteristics of the heating element may be examined. When we find a certain law, we call it C
The power supply control to the heater can be stopped in accordance with a certain rule by incorporating it into a storage control device such as a PU.

The heater A does not necessarily have to be put into water, but may be a type that keeps heat from outside the circulatory system.

[0021]

As described above, according to the aquarium water warming device according to the present invention, when the heater is exposed from the aquarium water, a safe aquarium water warming device that does not cause a personal injury, a fire accident, or damage to the heater. Succeeded in offering.

[Brief description of the drawings]

FIG. 1 is a view showing an embodiment of an aquarium water warming device according to the present invention.

FIG. 2 is a view showing an embodiment of an aquarium water warming device according to the present invention.

[Explanation of symbols]

 A heater B commercial power supply C power supply control stop circuit e power supply cutoff device p current detection device x analog / digital converter y computer unit

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[Procedure amendment]

[Submission date] February 25, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

As described above, by detecting and storing the stable steady-state current in water, if the power supply is stopped at an arbitrary value according to a certain rule according to a certain rule, the same circuit is randomly selected.
It does not cause the surface temperature of the heater is higher than any temperature.

Claims (2)

[Claims] 1. In the field of a water tank water warming device that heats and heats water in a water tank by supplying power to a heater from a power supply circuit, a current measurement function flowing to the heater is provided in the power supply circuit to measure a change in current value. And detects a constant current value change,
A device for controlling and stopping the power supply to the heater (Japanese Patent Application No. Hei 8-
278535), wherein a current at the time of power supply, for example, a rush current value or a current value after a certain time is detected and stored, and the power supply to the heater is stopped for any current change based on the detected value. Water warming equipment. 2. The apparatus according to claim 1, wherein after the power supply is stopped, the power supply is restarted by recognizing that any resistance or a resistance value has returned to a steady range value due to cooling, or automatically by a timer or the like. The water supply to the heater is started and the operation according to claim 1 is repeated. [0001]