JPH0320388Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention is a control circuit for a sanitary cleaning device that squirts warm water into private parts such as the anus to clean the private parts, and more specifically, a temperature sensor that detects the temperature of a heater and hot water. Regarding things that are equipped with.

<Conventional technology> Conventionally, this type of sanitary cleaning equipment has been equipped with an instant heating type heat exchanger, which can discharge water at an appropriate temperature for a long time even when the water supply temperature is low, especially in winter, and can be used by the next person immediately after use. We are using equipment.

<Problem that the invention aims to solve> However, with such conventional sanitary washing devices, the amount of washing water spouted is larger than necessary depending on the user's preference, or when the water temperature is extremely low such as in winter. The drawback is that washing water at an appropriate temperature cannot be supplied.

To eliminate this drawback, it is possible to increase the heater capacity of the heat exchanger, but as is well known, in ordinary households, the contract current (for example, 10A, 15A, 20A contract, etc.)
Based on this, a so-called safety breaker is installed for protection, and if the heater capacity of the heat exchanger is increased, the current exceeds the contract current when the device is in use. flows and trips the safety breaker, making it unsuitable for general home use.

From this point of view, the selection of the heater capacity of the heat exchanger is naturally subject to restrictions.

However, on the other hand, it is also necessary to heat the washing water discharged from the heat exchanger to a temperature suitable for use in order to obtain a comfortable feeling of use.

Considering these points, if the heater capacity is selected to the maximum allowable value, the heater conductor resistance value will have a product tolerance so-called variation (for example, ±10%).
If a heat exchanger heater with a conductor resistance value at the upper limit is used, the equipment will be used under the worst conditions in relation to the contracted current in each household and the usage conditions of various household electrical devices. In some cases, there is a problem that the safety breaker may trip.

In order to solve this problem, it may be possible to equalize the conductor resistance values of the heaters incorporated in the heat exchangers of all devices, but this would require measuring and selecting the conductor resistance values of many heaters one by one. There was a problem in that it required a lot of effort and made the device expensive.

Therefore, it is conceivable to stop the operation of the entire circuit and break the circuit when the household current flows through the heating element, as disclosed in Japanese Patent Application Laid-Open No. 49-65485, but this method does not allow the circuit to Since it does not have a return function that automatically enables the power to be reenergized after it has been cut off, it is necessary to manually reenergize the circuit every time the household current flows through the circuit, which is troublesome and requires a lot of cleaning water. There is a problem in that it takes a long time to heat up to the set temperature, so it cannot be used in sanitary cleaning equipment.

In view of such conventional circumstances, the present invention aims to maintain the contracted current by rapidly raising the cleaning water to a set temperature while suppressing the maximum energization to the heater.

<Means for solving the problem> The technical means taken by the present invention to solve the above problem is that the heater is connected to the power source via a switching element, and the gate of this switching element is connected to the detected value of the temperature sensor. A circuit that compares and outputs a reference value corresponding to the heating set temperature of hot water, a gate drive circuit that is connected to this circuit and outputs a gate signal to the switching element, and a current that is connected to the heater and detects the current. A control device is provided that includes a detection circuit and a current control circuit that compares the value output from the current detection circuit with a specified value corresponding to the maximum power consumption and outputs it to the gate drive circuit, and detects the temperature sensor. Forcibly blocks the gate signal of the switching element when the value reaches the reference value or when the heater current exceeds the specified value, and causes the gate signal of the switching element to flow when the heater current returns to the specified value. It is characterized by this.

<Operation> According to the above-mentioned technical means, the present invention cuts off current when a current exceeding a specified value flows through the heater, and then resumes energization when the current of the heater returns to within the specified value, thereby turning the temperature sensor on. The heater is intermittently energized until the detected value reaches the reference value.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the figure, 1 is a power supply terminal connected to an AC power source (not shown) of AC100V, for example. 2 is heating device K
A heater installed together with a temperature sensor S ₁ inside the
It is also connected to the power supply terminal 1 through a switching element 4 consisting of a triax or the like.

The heating device K connects the water supply pipes 5 to the water inlet 3a and the water outlet 3b of the cylindrical case 3 to communicate with each other, and the heater 2 disposed inside the case 3 has a hollow It is formed by printing a resistor on the surface of a cylindrical ceramic, coating it with a ceramic insulation protective layer, and sintering it at high temperature.The heater 2 is connected to the water inlet 3a of the case 3.
The water that enters from the water inlet 3a passes through the hollow of the ceramic, contacts the surface of the ceramic, and is discharged from the water outlet 3b. 2 and is heated and discharged.

The temperature sensor _S1 is formed by printing a resistor on the surface of ceramic, coating the ceramic insulating protective layer on top, and sintering this at high temperature, and is located near the water outlet 3b in the case 3. The temperature of the water discharged from the water outlet 3b is detected. And the above temperature sensor S ₁
A material that exhibits a positive characteristic in which the resistance value increases as the temperature rises is used. Furthermore, even if the water supply is temporarily stopped, a certain amount of water remains in the case 3 to prevent so-called "dry boiling" caused by the heater 2, and this remaining water is removed by the heater 2. Main temperature sensor S ₁ above to avoid heating
is detected by the switching element 4.
It is designed to control opening and closing.

Next, the control device 7 will be explained. Reference numeral 8 denotes a resistor-to-voltage conversion circuit connected to the temperature sensor S ₁ and configured to convert the change in resistance value detected by the temperature sensor S ₁ into a voltage and output it. Reference numeral 9 denotes an amplifier circuit into which the output Vin of the resistor-voltage conversion circuit 8 is input, and the other input terminal of the amplifier circuit receives the temperature of the cleaning water jetted from the nozzle 6 (for example, 39
By inputting the output Vref of the reference value setting circuit 10, which sets the output corresponding to (°C) by voltage,
These two inputs are compared, and when both inputs have a relationship of Vin≦Vref, a signal _V1 with an output of zero is sent out.

Reference numeral 11 denotes a zero-cross detection circuit which receives the output of a full-wave rectified waveform from the diode bridge DB ₁ connected between the power supply terminal 1 and sends out a pulse signal at the zero point of the input waveform. Reference numeral 12 is connected to the output terminal of the zero-cross detection circuit 11, and the output is made zero by the pulse signal of the zero-cross detection circuit 11, and a sawtooth wave output V is synchronized with the half-wave of the AC power input to the power supply terminal 1. This is a sawtooth wave generation circuit that sends out ₂ . Reference numeral 13 denotes a comparison circuit connected to the output terminals of the amplifier circuit 9 and the sawtooth wave generation circuit 12, and these two inputs V ₁
and _V2 , and output an "H" or "L" level output signal.

Reference numeral 14 denotes a gate drive circuit connected to the output terminal of the comparator circuit 13, and is configured to send a gate signal to the switching element 4 in response to an input signal of "H" level.

A current detection circuit 15 is connected to the output end of the heater 2 and detects the current of the heater 2. 16
is a current control circuit which inputs the output _V5 of the current detection circuit 15, and when the current of the heater 2 exceeds a specified value, a signal to block the gate signal of the comparison circuit 13 is sent to the gate drive circuit 1.
It is set to be sent at 4.

To further explain with reference to FIG. 2 which embodies this control device 7, the resistor-voltage conversion circuit 8 includes a resistor R ₁ and a temperature sensor S ₁ inserted in series between the constant voltage power supply Vcc and the ground. ₁ and the temperature sensor S ₁ are connected to each other as the output terminal. And the resistance value and resistance R ₁ according to the temperature detected by temperature sensor S ₁
The output voltage divided by the above resistor-voltage conversion circuit 8
It is designed to be sent out from the output terminal as the output Vin. The reference value setting circuit 10 is a constant voltage power supply Vcc.
A variable resistor VR ₁ and a resistor R ₂ are inserted in series between the variable resistor VR 1 and the resistor R 2, and the connection point between the variable resistor VR ₁ and the resistor R ₂ is formed as an output terminal. The temperature of the water is the set temperature (e.g.
39℃}, and the voltage corresponding to this value is sent out as output.

The amplifier circuit 9 connects the inverting input terminal of the single power supply operational amplifier OP ₁ to the output terminal of the reference value setting circuit 10 through a resistor R ₃
The non-inverting input terminal is connected to the output terminal of the resistor-voltage conversion circuit 8 via the resistor _R4 , and the resistor is connected to the output terminal of this operational amplifier _OP1 and the inverting input terminal.
Insert R ₅ and R ₆ in series, and connect the connection point of resistors R _{5 and} R ₆ to the ground via resistor R ₇ to connect to the input Vref.
Compare Vin, and compare both inputs Vref and Vin is Vref≧
When the relationship is Vin, the output signal is zero, and
When the relationship is Vref<Vin, the difference Vref−Vin
is amplified by a degree of amplification (for example, several hundred times) determined by resistors R ₃ (R ₃ = R ₄ ), R ₅ , R ₆ , and R ₇ and output.

The zero cross detection circuit 11 connects the collector of a transistor _Q1 whose emitter is grounded to a constant voltage power supply Vcc via a resistor _R9 , and connects a resistor between the base and emitter.
_R11 is inserted, and the anode of the diode _D1 whose cathode is connected to the base is connected to the positive DC output terminal of the diode bridge _DB1 through the resistor _R10 , and the collector of the transistor _Q1 is used as the output terminal.
Transistor _Q1 that turns off at the zero point of the full-wave rectified voltage
A pulse signal is sent out from the output end (collector). Sawtooth wave generation circuit 12
Insert resistors _R13 and _R14 and capacitor _C1 in series between constant voltage power supply Vcc and ground, and connect the above resistor _R13 and
Diode D ₂ with anode connected to the connection point of R ₁₄
The cathode of is connected to the collector of a transistor Q whose emitter is grounded, and the zero cross detection circuit 1 is connected to the base of this transistor _Q2 via a resistor _R12 .
Connect the collector of the transistor Q ₁ of 1, and use the connection point of the above resistors R ₁₃ and R ₁₄ as the output terminal, and when the transistor Q ₂ is off, the capacitor C ₁ is the resistor.
It is charged through R ₁₃ and R ₁₄ and the voltage at the output terminal rises, and when transistor Q ₂ is turned on, the capacitor
C ₁ discharges in the circuit of resistor R ₁₄ → diode D ₂ → collector/emitter of transistor Q ₂ → C ₁ , so that the voltage at the output end rapidly drops to zero, and the half-wave of the AC power input to power supply terminal 1 is generated. It is designed to send out a sawtooth wave-like output V ₂ that is synchronized with. The comparator circuit 13 connects the output terminal of the operational amplifier OP ₁ of the amplifier circuit 9 to the inverting input terminal of the operational amplifier _{OP 2} , and connects the output terminal of the sawtooth wave generation circuit 12 to the non-inverting input terminal of the operational amplifier OP _2. Connect the output terminal of the amplifier circuit ₉ through the resistor R15 to output the amplifier circuit 9.
When the output V ₂ of the sawtooth wave generation circuit ₁₂ becomes larger than V 1 (V ₁ ≦V ₂ ), the “H” level output signal sent from the operational amplifier OP ₂ is sent as the output of the comparison circuit 13. ing. The gate drive circuit 14 connects the base of a transistor _Q3 whose emitter is grounded to the output terminal of the operational amplifier _OP2 , and connects the anode of a diode _DL6 whose cathode is connected to the collector of this transistor _Q3 via a resistor _R16 . The transistor Q3 is connected to the gate of the switching element 4, and when the input is an "H" level signal, the transistor _Q3 is turned on and the switching element 4 is turned on.

The current detection circuit 15 connects the primary side of the transformer T ₂ to the heater 2, connects the AC input terminal of a diode bridge DB ₂ in which diodes are formed into a bridge circuit to both ends of the secondary coil, and connects this diode to both ends of the secondary coil. A resistor R ₂₁ and a capacitor are connected to the DC output end of the bridge DB ₂ through a diode D ₉ inserted in the forward direction.
C ₇ is connected to send out an output voltage V ₅ corresponding to the average value of the current flowing through the heater 2.

In addition, the current control circuit 16 is a comparator whose output terminal is an oven collector transistor.
The above current detection circuit 16 is connected to the inverting input terminal of CMP ₁ .
The output end of is connected via variable resistor VR ₂ and resistor R ₂₂ , and a resistor R ₂₃ is connected between constant voltage power supply Vcc and ground.
and R ₂₄ in series, connect the connection point of the above resistors R ₂₃ and R ₂₄ to the non-inverting input terminal, and connect the comparator.
The output terminal of CMP ₁ is connected to the gate drive circuit 14.
is connected to the base of transistor _Q3 . Both inputs V ₃ and V ₄ of the comparator CMP ₁ become V 3 = V ₃ when the current flowing through the heater 2 reaches the maximum value determined from the maximum power consumption allowed by the device.
The voltage division ratio of the variable resistor VR ₂ that divides the output V ₅ of the current detection circuit 15, and the _voltage division ratio of the resistors R ₂₃ and R ₂₄ that divide the constant voltage power supply Vcc are set so that the relationship is V 4 . There is. In other words, this current control circuit 16 inputs V ₃ to the comparator CMP ₁ using the average value of the current flowing through the heater 2 as an effective value,
This is compared with the specified value VV ₄ , and when the current flowing through the heater 2 exceeds the specified value, the transistor whose output terminal is the oven collector is turned on and the current is supplied to the transistor Q ₃ of the gate drive circuit 14. By allowing a base current to flow into the transistor Q3, the transistor _Q3 is turned off, thereby blocking the gate signal of the switching element 4.

Next, its operation will be explained.

First, when the power terminal 1 is connected to an AC power source while water is flowing through the water supply pipe 5 into the heating device K,
The diode bridge DB ₁ outputs a full-wave rectified waveform (output of DB ₁ in Figure 3). In the initial state, the temperature detected by the temperature sensor S ₁ is low, so the resistance value is also low. Therefore, both inputs of the amplifier circuit 9 have a relationship of Vref≧Vin, so the output V ₁ is zero. The output signal of the comparison circuit 13 becomes "H" level, turning on the transistor _Q3 of the gate drive circuit 14, thereby turning on the switching element 4 and energizing the heater 2.

The water flowing through the heating device K is thereby heated. This heated water is discharged from the water outlet 3b of the heating device K, and a temperature sensor detects this.
The resistance value of S ₁ also increases as the detected temperature increases, which causes the output Vin of the resistor-voltage conversion circuit 8 to also increase, but both inputs Vref and
Since the output _V1 of the amplifier circuit 9 is zero until the relationship of Vin becomes Vref<Vin, the heater 2 continues to be energized. Then, the input Vin of the amplifier circuit 9
When Vref is larger than Vref and Vref<Vin, the amplifier circuit 9
outputs an output _V1 obtained by amplifying the difference between the two inputs, Vref-Vin, by a predetermined amplification degree.

Therefore, the output _V1 of the amplifier circuit 9 is between zero and Vcc volts.

Also, the zero-cross detection circuit 11 that receives the full-wave rectified voltage from the diode bridge DB ₁ is turned off while the base input of the transistor Q ₁ is lower than the base-emitter voltage (0M.6V), and the pulse signal is supplied from the collector. Since it is sent out in synchronization with the zero point of the power supply voltage input to terminal 1 (output in Figure 3, 11),
In response to this, the sawtooth wave generating circuit 12 turns on the transistor Q ₂ to discharge the capacitor C ₁ when receiving the pulse signal, and during the stop period of the pulse signal, the transistor Q ₂ turns off and discharges the capacitor C ₁ . A constant voltage power supply Vcc charges the battery through resistors R ₁₃ and R ₁₄ to generate a sawtooth wave output signal in synchronization with the zero point of the AC power supply. This sawtooth waveform output signal is repeatedly generated at a level that is higher than the zero level by the collector-emitter saturation voltage of the transistor Q ₂ and the forward voltage drop (0.6 V) of the diode D ₂ . (Figure 3
V ₂ ) at the input of OP ₂ ). Therefore, the lowest potential of the output _V2 of the sawtooth wave generating circuit 12 is 0.6V.

In this case, the comparison circuit 13 is the output of the amplifier circuit 9.
Since V ₁ is between zero and Vcc volts, the heater 2 can be energized via the gate drive circuit 14 with the control angle of the switching element 4 at zero degrees (output of OP ₂ in FIG. 8). In this case, the applied current increases for heaters with a large capacity and exceeds the maximum power consumption.

On the other hand, in the current detection circuit 15, an instantaneous value corresponding to the current supplied to the heater 2 is output as a voltage to the secondary side of the transformer _T2 (output of _T2 in Fig. 3), and is outputted by the diode bridge _DB2 . A full-wave rectified waveform is output (output of DB ₂ in Figure 3), and the output of this diode bridge DB ₂ is provided to an integrating circuit formed by a resistor R ₂₁ and a capacitor C ₇ through a diode D ₉ and a diode D 9. The output V ₅ is integrated by
The average value is obtained.

Therefore, a voltage V ₅ corresponding to the average value of the current flowing through the heater 2 is obtained.

The current control circuit 16 then applies the voltage obtained by the output _V5 of the current detection circuit 15 to a variable resistor.
The voltage supplied to the inverting input terminal of comparator CMP ₁ through VR ₂ resistor R ₂₂ is set to V ₃ , and the voltage V ₄ supplied to the non-inverting input terminal corresponds to the maximum value of the current flowing through heater 2. Therefore, the comparator CMP ₁ whose output terminal is an open collector transistor has an inverting input V ₃ > a non-inverting input
When V ₄ , this transistor turns on and the transistor of the gate drive circuit 14 is transferred from the comparator circuit 13.
When the transistor _Q3 is turned on, the base current supplied to Q3 flows through it and is no longer supplied, so that the transistor _Q3 is turned off, and the gate current does not flow to the switching element 4, so that the switching element 4 cannot be turned on. Conversely, when the inverting input V ₃ <non-inverting input V ₄ , the output transistor of the comparator CMP ₁ is turned off, so the gate drive circuit 14
The transistor Q ₃ is supplied with the base current from the comparator circuit 13, and the transistor Q ₃ is turned on, the switching element 14 is turned on, and the heater 2 is energized.

As described above, when a current exceeding a specified value flows through the heater 2, the inverting input _V3 becomes greater than the non-inverting input _V4 , and the switching element 4 is controlled so as not to be turned on, thereby limiting the current flowing through the heater 2.

<Effects of the Invention> Since the present invention has the above configuration, it has the following advantages.

When a current higher than the specified value flows through the heater, the current is cut off, and when the heater current returns to the specified value or higher, the current is restarted and the heater is energized intermittently until the detected value of the temperature sensor reaches the reference value. Therefore, the contract current can be maintained by quickly raising the cleaning water to the set temperature while suppressing the maximum energization to the heater.

Therefore, even when fully energized, the maximum current consumption can be kept constant regardless of the product, and the amount of cleaning water spouted can be increased more than necessary depending on the user's preference.
Even when the water temperature is extremely low, such as in winter, the safety breaker can supply cleaning water at an appropriate temperature in a short time without tripping.

Since it is not necessary to make the resistance values of the heaters uniform for all products, it can be handled at a low cost.

By detecting the maximum value of the current flowing through the heater using the average value of the current, it is possible to simplify the circuit configuration and reduce costs without using a complicated current effective value detection circuit.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing one embodiment of the control circuit of the sanitary cleaning device of the present invention, Fig. 2 is a block diagram showing a more specific configuration of the configuration of Fig. 1, and Fig. 3 is a time chart explaining the operation. be. 1...Power supply (power terminal), 2...Heater, 4...
...Switching element, 7...Control device, 9...Circuit for comparing the detected value of the temperature sensor and the reference value (amplification circuit), 14...Gate drive circuit, 15
...Current detection circuit, 16...Current control circuit, S ₁ ...
…Temperature sensor.

Claims (1)

[Scope of utility model registration request] In a sanitary cleaning device equipped with a heater and a temperature sensor that detects the temperature of hot water, the heater is connected to a power source via a switching element, and the gate of this switching element is connected to the detected value of the temperature sensor and the heating set temperature of the hot water. A circuit that compares and outputs a corresponding reference value, a gate drive circuit that is connected to this circuit and outputs a gate signal to the switching element, a current detection circuit that is connected to the heater and detects the current, and a gate drive circuit that is connected to this circuit and outputs a gate signal to the switching element. A control device is provided that includes a current control circuit that compares the value output from the detection circuit with a specified value corresponding to the maximum power consumption and outputs the result to the gate drive circuit, so that the detected value of the temperature sensor reaches the reference value. A sanitary device characterized in that the gate signal of the switching element is forcibly blocked when the heater current returns to within the specified value, and the gate signal of the switching element is made to flow when the heater current returns to within the specified value. Control circuit for cleaning equipment.