JPS6337735Y2 - - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a floor heating system.

As shown in FIG. 1, a conventional floor heating device such as an electric heating board has a main body 1 containing a surface heating element 2, a plurality of thermostats 3, and a plurality of temperature fuses 4. A plurality of distributed thermostats 3 and a plurality of temperature fuses 4 are connected in series, and both ends of this series circuit are connected to a corner 1a of the main body 1.
The power cord 5 is connected in series with the surface heating element 2, and the power cord 5 is drawn out from the corner 1a.

Specifically, as shown in FIG. 2, the main body 1 has a surface heating element 2 attached to the bottom surface of an insulating sheet 6 using an aluminum foil pattern, etc., and a plurality of thermostats 3 and a plurality of thermostats 3 on the top surface of the insulating sheet 6. A plurality of thermostats 3 and a plurality of temperature fuses 4 are arranged in a distributed manner, and an insulating sheet 7 is attached to the lower surface of the insulating sheet 6 so as to sandwich the surface heating element 2, and a plurality of thermostats 3 and a plurality of temperature fuses 4 are arranged on the upper surface of the insulating sheet 6. A steel plate 8 is attached so as to sandwich the , a backing material 9 is attached to the lower surface of the insulating sheet 7, and a surface material 1 is attached to the upper surface of the iron plate 8.
0 is pasted.

Note that 11 in FIG. 1 is a power switch, and 12 is a power plug.

This floor heating system controls the temperature by turning the power on and off using multiple thermostats 3, and
A plurality of temperature fuses 4 are used to prevent excessive rise, and an iron plate 8 placed directly below the surface material 10 prevents conductive pins (not shown) from piercing the surface heating element 2 to prevent electric shock. ing.

However, temperature control using the thermostat 3 has a large temperature difference between on and off times, making it impossible to perform precise temperature control. Further, the set temperature is also uniquely determined by the operating temperature of the thermostat 3, and the variation thereof is large. In addition, a plurality of temperature fuses 4 are provided in the main body 1.
Since overheating is prevented by incorporating a built-in device, assembly work such as wiring is not easy, which causes an increase in costs. In addition, since the iron plate 8 etc. was interposed directly under the surface material 10 to prevent electric shock,
It became heavy and could not provide cushioning properties.

Therefore, the object of this invention is to provide a floor heating device that can prevent electric shock, be lightweight, and provide cushioning properties.

An embodiment of this invention will be explained based on FIGS. 3 to 5. In other words, this floor heating system is
As shown in FIG. 3, a metal foil such as aluminum foil is pasted on the upper surface of the insulating film 14, and this metal foil is etched to form a surface heating element 15, and an NTC thermistor etc. is formed on the lower surface of the insulating film 14. A plurality of temperature sensors 16 are arranged in a distributed manner, an insulating film 17 is pasted on the top surface of the insulating film 14 so as to sandwich the surface heating element 15, and the top surface of the insulating film 17 is further coated with an insulating film 18. Metal foil 19 with a thickness of about 20 μm such as foil
The surface material 20 is pasted on the top surface of the insulating film 18.
The main body 13 is constructed by attaching a back material 21 to the lower surface of the insulating film 14 so as to sandwich the temperature sensor 16 therebetween.

In addition, this floor heating system has a fourth electrical circuit.
As shown in the figure, connect the power switch SW to the AC power source E.
The secondary output of the step-down transformer T is rectified and smoothed by the power supply circuit EE to obtain a DC voltage V _DD , and this DC voltage V _DD
Switching the relay through transistor _Q1
In addition to RY, the voltage of AC power source E is applied between terminals H ₁ and H ₂ of surface heating element 15 from the load side of power switch SW via relay contacts ry ₁ and ry ₂ of relay RY. Note that _D1 is a diode for surge absorption.

In addition, the DC voltage V _DD is divided by resistors R ₁ and R ₂ and the voltage V _C across the resistor R ₂ is applied as a power supply voltage to a temperature control comparator CP ₁ and an over-rise prevention comparator CP ₂ . A voltage V ₁ obtained by dividing the DC voltage V _DD by the resistor R ₃ and the temperature sensor ₁₆ is applied to the positive input terminal of the comparator CP ₁ and the negative input terminal of the comparator CP 2, and the DC voltage V is applied to the negative input terminal of the comparator CP ₁ . _DD to resistor R ₄ and variable resistor for temperature adjustment
VR, voltage V ₂ divided by resistors R ₅ to _{R 7} is applied to the positive input terminal of comparator CP ₂ , and voltage V ₂ input to the negative input terminal of comparator CP ₁ is applied to resistor R ₆ and resistor R ₇ . The output voltage V ₄ of the comparator CP ₁ is applied to _the positive input terminal of the comparator CP ₁ via the feedback resistor R ₈ to provide hysteresis in the operation of the comparator CP ₁ .

The output voltage V ₄ of the comparator CP ₁ is applied via the resistor R ₉ to the base of the aforementioned switching transistor Q ₁ , and the output voltage V ₅ of the comparator CP ₁ is applied via the resistor R ₁₀ to the gate of the thyristor SCR _1. It is being This thyristor SCR ₁ is a heating resistor
R ₁₁ is connected in series to the anode side, and a resistor R ₁₂ is connected between the gate and cathode, which is connected in parallel to the surface heating element 15. The temperature fuse TF, which is thermally coupled to the heating resistor R ₁₁ , is connected from the AC power source E. It is inserted in series in the power supply path to the load.

Also, connect a diode to one terminal _H2 of the surface heating element.
Connect one end of resistor R ₁₃ through D ₂ and
One end of a resistor R ₁₄ is connected to the other terminal H ₁ of the surface heating element 15 via a diode D ₃ , the other ends of the resistors R ₁₃ and R ₁₄ are commonly connected, and this common connection point is connected to the metal foil 19 .
between the primary winding of the pulse transformer PT and the resistor
Connect the parallel circuit with R ₁₅ and pulse transformer PT
The secondary winding of thyristor SCR 2 is connected between the gate and cathode of thyristor SCR ₂ via resistor R ₁₆ . This thyristor SCR ₂ is connected in parallel to resistor R ₂ with resistor R ₁₇ connected between the gate and cathode.

Next, the operation of this floor heating system will be explained.

When the power switch SW is turned on, a DC voltage V _DD appears on the output side of the power supply circuit EE, and the comparator
A voltage V _C is applied to CP ₁ and CP ₂ to enter the operating state. A voltage V ₁ obtained by dividing the DC voltage V _DD by the resistor R ₃ and the temperature sensor 16 is applied to the positive input terminal of the comparator CP 1, and a voltage V ₁ obtained by dividing the DC voltage V _DD by the resistor R ₃ and the temperature sensor 16 is applied to the negative input terminal. and variable resistance VR and resistance R ₅
A voltage V ₂ divided by ~R ₇ is applied, but since the temperature of the main body 13 is low immediately after turning on the power switch SW, the resistance value of the temperature sensor 16 is high, and V ₁ > V ₂
, the output voltage V ₄ of the comparator CP ₁ becomes high level, the switching transistor Q ₁ is turned on, the relay RY is energized, and the relay contacts ry ₁ ,
ry ₂ is closed, the AC power source E energizes the surface heating element 15, the surface heating element 15 generates heat, and the temperature of the main body 13 gradually rises.

As the temperature of the main body 13 rises due to energization of the surface heating element 15, the resistance value of the temperature sensor 16 decreases, and when V ₁ > V ₂ , the output voltage V ₄ of the comparator CP ₁ becomes a low level and switches. Transistor Q ₁ is turned off, excitation of relay RY is stopped, relay contacts ry ₁ and ry ₂ are opened, and current flow from AC power source E to surface heating element 15 is stopped, and heating of surface heating element 15 is stopped. , the temperature of the main body 13 gradually decreases. At this time, the feedback resistor _R8 is connected in parallel to the temperature sensor 16, and the comparator
The input voltage to the positive input terminal of CP ₁ is from voltage V ₁ to resistance
The voltage drops to a voltage V' ₁ (V' ₁ <V ₁ ) divided by R ₃ , the temperature sensor 16, and the feedback resistor R ₈ .

As the temperature of the main body 13 decreases, the resistance value of the temperature sensor 16 increases, and when V' ₁ > V ₂ ,
The output voltage V ₄ of the comparator CP ₁ becomes high level and the switching transistor Q ₁ is turned on.
Relay RY is energized, relay contacts ry ₁ and ry ₂ are closed, energization to surface heating element 15 is resumed, and main body 1
3 temperature rises again.

Thereafter, the same operation is repeated, and the temperature of the main body 1 is maintained at the temperature set by the variable resistor VR.

Also, voltage V ₁ is applied to the negative input terminal of comparator CP _2.
is applied and a voltage V ₃ is applied to its positive input terminal.
(V ₃ < V ₂ ), but if temperature control by comparator CP ₁ is performed normally, the voltage
Since the control set temperature by V ₂ is lower than the overrise prevention set temperature by voltage V ₃ , the state of V ₁ > V ₃ continues,
The output voltage V ₅ of the comparator CP ₂ is at a low level, the thyristor SCR ₁ does not conduct, the heating resistor R ₁₁ does not generate heat, and the temperature fuse TF does not blow out.

However, due to welding of the relay contacts ry ₁ and ry ₂ or a short circuit of the switching transistor Q ₁ , temperature control becomes impossible, and the temperature of the main body 13 falls below the voltage V _{2 .}
The resistance voltage V ₂ rises higher than the set temperature due to
When the overrise prevention set temperature, which is set a certain temperature higher than the control set temperature by voltage division with R ₆ and R ₇ , is exceeded and V ₁ < V ₃ , the output voltage V ₅ of comparator CP ₂ becomes high level, and the thyristor A gate voltage is applied to the SCR ₁ to make it conductive, and the heating resistor R ₁₄ is energized to blow the thermally coupled temperature fuse TF, thereby blocking power supply from the AC power source E and preventing the temperature of the main body 13 from rising excessively.

Furthermore, the metal foil 19 and the surface heating element 15 are connected from the AC power source E through a series circuit of a diode D ₂ and a resistor R ₁₃ or a series circuit of a diode D ₃ and a resistor R ₁₄ and the primary winding of the pulse transformer PT. Usually, an insulating film 17 with high impedance is interposed between the metal foil 19 and the surface heating element 15, so one of the pulse transformers PT
No current flows through the secondary winding and no voltage is induced in the secondary winding of the pulse transformer PT, so thyristor SCR ₂ shuts off and the voltage is applied to comparators CP ₁ and CP ₂ .
V _C is added.

However, as shown in FIG.
5 is short-circuited, terminal H ₂ - diode D ₂ → resistor R ₁₃ → primary winding of pulse transformer PT → metal foil 19 → conductive pin 22 → surface heating element 15 → terminal H ₁
path or terminal H ₁ → diode D ₃ → resistor R ₁₄ →
A current flows through the path of the primary winding of the pulse transformer PT → metal foil 19 → conductive pin 22 → surface heating element 15 → terminal _H2 , and a pulse voltage is induced in the secondary winding of the pulse transformer PT, causing the thyristor SCR. ₂ , the thyristor SCR ₂ becomes conductive and short-circuits both ends of the resistor R ₂ , and the voltage V _C drops to 0 [] to stop the operation of the comparators CP ₁ and CP ₂ , and the comparator CP ₁ By setting the output voltage V ₄ to a low level, the switching transistor Q ₁ is forcibly cut off, the excitation of the relay RY is stopped, relay contacts ry ₁ and ry ₂ are opened, and the surface heating element 15 is energized. to prevent electric shock. In this case, one half-wave current of the AC power source E is caused to flow through the primary winding of the pulse transformer PT via a path passing through the diode _D2 , and the other half-wave current of the AC power source E is caused to flow through the path passing through the diode _D3 . Therefore, even if any part of the metal foil 19 and the surface heating element 15 with different potential distributions is short-circuited with the conductive pin 22, a pulse voltage is induced in the pulse transformer PT and the current supply to the surface heating element 15 is stopped. be able to.

As described above, in the floor heating system of this embodiment, the temperature of the main body 13 is detected by the temperature sensor 16, and the detected temperature and the control set temperature are compared by the comparator CP ₁ having a certain hysteresis. Since the temperature of the main body 13 is maintained at the control set temperature by on-off control of the electricity supply to the surface heating element 15, the temperature difference between on and off times can be reduced, and the control set temperature can be arbitrarily adjusted without variation. The temperature of the main body 13 can be precisely controlled. In addition, the temperature sensor 16
Comparator CP ₂ compares the detected temperature with the over-rise prevention set temperature, and when the detected temperature exceeds the over-rise prevention set temperature, the heating resistor R ₁₁ is energized and the temperature fuse TF is blown. The temperature fuse TF does not need to be built into the main body 13 as in the conventional example, and lead wiring inside the main body 13 is no longer necessary, making wiring work easier. Also, only one temperature fuse TF is required, reducing costs. be able to. Further, a metal foil 19 is arranged above the surface heating element 15, and a voltage is constantly applied between the metal foil 19 and the surface heating element 15, so that when the conductive pin 22 is inserted into the main body 13, the metal foil 19 The surface heating element 15 is short-circuited, and the short-circuit current is used to conduct the thyristor SCR ₂ through the pulse transformer PT, and the comparator CP ₁ ,
Electric shock is prevented by stopping the power supply to CP ₂ , stopping the excitation of relay RY, and opening relay contacts ry ₁ and ry _2. Therefore, the iron plate 8 to prevent conductive pins from piercing is used instead of the conventional one. etc., and only the thin metal foil 19 is required, making it possible to reduce the weight of the main body 13 and provide cushioning properties to the main body 13. Further, the heat of the surface heating element 15 is easily conducted to each part of the main body 13 by the metal foil 19, and the surface temperature of the main body 13 can be made almost uniform.

This invention can also be applied to small-area hot carpets.

As described above, the floor heating device of this invention includes a main body in which a planar electrode is arranged above a surface heating element via an insulating film, a temperature sensor is arranged near the surface heating element, and an output of the temperature sensor. a temperature control circuit that controls the temperature of the main body to be constant by intermittent energization to the surface heating element based on the above; and a voltage application circuit that applies a voltage between the planar electrode and the surface heating element; a pulse transformer that generates a pulse voltage with a current flowing through the voltage application circuit due to a short circuit between a plane electrode and the plane heating element;
Since it is equipped with a switch circuit that forcibly cuts off the electricity to the surface heating element in response to the pulse voltage generated from the pulse transformer, it is possible to prevent electric shock and to reduce the weight of the main body. This has the effect of being able to provide cushioning properties to the main body.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a conventional floor heating system, Fig. 2 is a sectional view of its main parts, Fig. 3 is a sectional view of main parts of a floor heating system according to an embodiment of this invention, and Fig. 4 is an electric circuit as well. 5 are sectional views of essential parts for explaining the operation. 13...Main body, 14...Insulating film, 15...
... Surface heating element, 16 ... Temperature sensor, 17 ... Insulating film, 19 ... Metal foil, E ... AC power supply,
EE...power supply circuit, _Q1 ...switching transistor, RY...relay, ry ₁ , ry ₂ ...relay contact,
CP ₁ , CP ₂ ... Comparator, SCR ₁ , SCR ₂ ...
Thyristor, _R11 ...Heating resistance, TF...Temperature fuse, PT...Pulse transformer.

Claims (1)

[Claims for Utility Model Registration] (1) A main body in which a planar electrode is arranged above a surface heating element via an insulating film, and a temperature sensor is arranged near the surface heating element, and a body based on the output of the temperature sensor. a temperature control circuit that controls the temperature of the main body to be constant by intermittent energization to the surface heating element; a voltage application circuit that applies a voltage between the planar electrode and the surface heating element; and a voltage application circuit that applies a voltage between the planar electrode and the planar heating element; and a pulse transformer that generates a pulse voltage with a current flowing through the voltage application circuit when the surface heating element is short-circuited, and a pulse transformer that forcibly cuts off current to the surface heating element in response to the pulse voltage generated from the pulse transformer. Floor heating system equipped with a switch circuit. (2) The floor heating device according to claim 1, wherein the switch circuit forcibly cuts off power supply to the surface heating element by stopping power supply to the temperature control circuit. .