JPH0345855A - Temperature control device of hot water feeding device - Google Patents

Abstract

PURPOSE:To enable all the setable temperatures to be set irrespective of a presence of scattering in a variable resistance value by a method wherein in the case that the set resistance value is more than a specified resistance value, it is set to a minimum temperature of settable temperature and as the set resistance is lower, its target temperature is set high. CONSTITUTION:When a user sets a hot water feeding temperature by a variable resistance circuit 51 (61) of a remote controller 50 (60) selected, voltages at the terminals 36, 37 (38, 39) corresponding to the resistance values in the variable resistance circuit are read as set temperature signals. At this time, in the case that the resistance value of the variable resistor VR1 (VR2) is more than the specified resistance value, the minimum temperature becomes a set temperature and in turn in the case that it is less than that, as the resistance value is lower in response to each of the resistance values, a higher temperature is set. At this time, as to a hot water temperature thermistor 25, its detected temperature signal is also read and then an amount of combustion is determined with the signal being applied as a heating information. After this, as a hot water feeding plug is opened, an ignition is carried out at a predetermined sequence and then an ignition is carried out at a group of burners 11.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a water heater that includes a variable resistor for setting the hot water temperature, and sets a target temperature according to the resistance value of the variable resistor. The present invention relates to a temperature control device for a water heater.

[Prior Art] A temperature control device for a water heater that sets the hot water temperature according to the operating state of a variable resistor is designed to set the temperature at a location away from the main body of the water heater. Some devices are equipped with a remote control section (hereinafter referred to as the "control section") that is connected with a main wire.

In such a control device, for example, a variable resistor is provided in the operation section, and a constant voltage is applied from the control device to the variable resistor, and the voltage changes depending on the resistance value of the variable resistor.
The control device detects this and determines the target temperature of the hot water.

In this case, in many water heaters, the temperature can be freely set between about 35°C and about 70'C depending on the operating state of the variable resistor.

[The problem that the invention tries to solve! ! By the way, variable resistors etc. have a tolerance of about ±10% for the total resistance value of the variable resistor, so generally speaking, if the resistance value of the variable resistor is set to a large value, the error will be The value increases.

Therefore, considering the error when the resistance value is set to the large side in the water heater temperature control device, the error is ±10
%, in order to be able to set the target temperature, the resistance value of the variable resistor must be 90% of the standard resistance value.
%, it is necessary to ensure that the target temperature can be set.

On the other hand, water heaters are used to supply hot water for filling baths, showers, kitchens, washrooms, etc., and the operating temperature for these is around 40℃, which is safe for the body, or around 35℃, which is lower than that. In many cases.

As a result, when setting the target temperature by moving the contacts of the variable resistor, 35
If the display part, such as a sketch to indicate the setting position of ℃ or 40℃, is biased to a part of the movable range of the contact or to one side, the aesthetic appearance will be spoiled, and the contact point when changing these temperatures will be damaged. Since the range of movement of the contacts is narrowed, the operation must be performed carefully when moving the contacts, and there is a problem in that the temperature cannot be set easily.

The present invention provides a temperature control device for a water heater that sets the temperature using a variable resistor, in which the target temperature can be reliably set even if there are variations in the variable resistor, and sketches indicating the target temperature are arranged in a well-balanced manner. The purpose is to be able to easily set each temperature.

[Means for Solving the Problems] The present invention includes a variable resistor that indicates a resistance value according to the contact position of a contact point to a resistor, and sets a target temperature according to the set resistance value of the variable resistor. In the temperature control device for a water heater, when the set resistance value is equal to or higher than a certain resistance value, the temperature is set to the lowest temperature that can be set, and the smaller the set resistance value is, the higher the target temperature is set. technical means to do so.

[Function] According to the present invention, when the set resistance value is equal to or higher than a certain resistance value, the lowest temperature is set, and the smaller the set resistance value is, the higher the target temperature is set. In this case, for example, as shown in FIG. 12, there are variations in the variable resistor, and the actual resistance value provided by the variable resistor is at the limit of the allowable range.
Assuming that the maximum resistance value is a resistance value r1 that is smaller than the standard maximum resistance value r0, if a smaller resistance value r2 is set as a constant resistance value for setting the minimum temperature, there will be variations in the variable resistor. When using any variable resistor, including a variable resistor whose maximum resistance value is larger than the standard maximum resistance value r3, this can be achieved by placing the contact at the end on the maximum resistance value side. Since it exhibits a value greater than a certain resistance value, the lowest temperature can be set no matter which variable resistor is used.

Furthermore, if the contacts of the variable resistor are moved to reduce the resistance value, the set temperature will increase.

In this case, the smaller the resistance value, the smaller the error.
When the contact point is moved to the end so as to have the minimum resistance value, the resistance value of the variable resistor becomes almost zero regardless of variations in the variable resistor. Therefore, any variable resistor can provide a minimum resistance value close to zero. Therefore, the maximum temperature can be set according to this minimum resistance value.

As a result, even if there are variations in the individual variable resistors, it is possible to set each temperature from the lowest temperature to the highest temperature while moving the contact point from the maximum resistance value side to the minimum resistance value side.

On the other hand, normally, the minimum temperature that can be set for a water heater is around 35℃, and the temperature that can be set by the user is
Most temperatures are around 35°C and around 40°C.

Here, when setting the minimum temperature, as mentioned above,
Since the contact point of the variable resistor can be moved to the end where the resistance value increases, the lowest temperature can be displayed near the end, and it is also the lower limit of the resistance value set at the lowest temperature. A position exhibiting a resistance value smaller than a certain resistance value is always provided at a location away from the end.

Therefore, the display indicating around 40° C. can be provided at an appropriate distance from the display indicating the lowest temperature toward the side where the highest temperature is set. As a result, when setting these temperatures individually, it is necessary to move the contacts reliably, so that they can be set clearly.

[Effects of the Invention] According to the present invention, even if there are variations in the variable resistors, all settable temperatures from the lowest temperature to the highest temperature can be set without fail.

In addition, the frequently used setting temperature is 35℃ or 40℃.
When providing sketches or the like to indicate the contact points, they can be dispersed without being too close to each other with respect to the moving range of the contact points. Therefore, the display is balanced, and when changing the set temperature, each setting is clearly distinguished, making it easy to change the setting.

[Example code] Next, the present invention will be explained based on embodiments shown in the drawings.

Inside the combustor case 10 of the gas water heater 1 shown in FIG.
A burner group 11 including a plurality of burners is arranged, and a blower 12 for supplying combustion air to the burner group 11 is provided below the combustor case 10. A wood-tube heat exchanger 13 is provided above the burner group 11 in the combustor case 10, and water passing through the interior is heated by combustion heat from the burner group 11. A sparker 14 for igniting the burner group 11 is provided near the burner group 11 in the combustor case 10, and a flame rod 15 for detecting ignition of the burner group 11 is provided to confirm the operation of the gas water heater 1.
is provided. An exhaust port 2 for discharging combustion exhaust gas to the outside is provided above the combustor case 10.

A nozzle pipe 16 for supplying fuel gas is provided below the burner group 11.
A plurality of fuel injection ports 16a for ejecting fuel gas are provided corresponding to each burner.

The fuel pipe 20 that guides the fuel gas to the nozzle pipe 16 includes two electromagnetic valves 21 and 22 that allow the fuel gas to pass when energized, and a governor that adjusts the amount of fuel gas supplied by controlling the supply pressure according to the energized current. Proportional valves 23 are provided in order from the upstream side.

A water supply pipe 17 that leads water from a water supply source (not shown) to the heat exchanger 13 is equipped with an electric water flow control device 18 for adjusting the amount of hot water supply, and a water flow switch 19 for detecting the amount of water passing through the heat exchanger 13. A hot water temperature thermistor 25 for detecting the hot water temperature of hot water flowing out from the heat exchanger 13 is installed in a hot water supply pipe 17a which is provided sequentially from the 1-stream side and leads the hot water flowing out from the heat exchanger 13 to a hot water supply port (not shown). It is equipped.

The gas water heater 1 having the above configuration is controlled by a control section W30 shown in FIG.

The control device 30 is mainly a microcomputer that has a sequence control section 31, a temperature control section 32, a combustion control section 33, a water control section 34, and a display control section 35 using 70 grams of ROM. main remote controllers (hereinafter referred to as "main remote controllers") 5 each driven by remote controller drive circuits 40 and 40a.
0 and a sub-remote controller (hereinafter referred to as "sub-remote controller") 60.

The control device 30 is provided with terminals 36, 37 for connecting the main remote controller 5o, and terminals 38, 39 for connecting the sub remote controller 6°.

The main remote control 50 has a terminal 36.3 of the control device 30.
Terminals 50A and 50B are provided for connection between the control device 30 and the main remote controller 50, and two electric wires 40A and 40B are used to connect each terminal of the control device 30 and the main remote controller 50. In this case, since the polarity is not particularly determined, the terminals 50A and 50B of the main remote controller 50 are connected to the terminal 3 of the control device 30.
6.37 may be reversely connected.

Similarly, the sub remote controller 60 has terminal 3 of the control device 30.
Terminals 60A and 60B are provided for connection between the terminals 8 and 39, and the terminals are connected by two wires 1i40C540D. Similarly, the sub remote controller 6
0 terminals 60A and 60B are terminals 38.0 of the control device 30.
39 may be connected in reverse.

First, the configuration of the main remote controller 50 will be explained.

The main remote controller 50 has a terminal 5 as shown in FIG.
A variable resistance circuit 51, an operation switch circuit 52, and a display circuit 53 are provided in parallel between 0A and 50B.

The variable resistance circuit 51 includes variable resistors VR1 connected in parallel.
and a resistor R1 are connected in series with a resistor R2, and the set temperature is determined according to the resistance value of the variable resistance circuit 51 which changes when the user operates the variable resistor VR1.

The operation switch circuit 52 consists of an operation switch SWl for instructing the start and stop of operation of the gas water heater I, and a resistor R3 connected in series with this, and the operation switch SW1 has a normally open push button. A button switch is used,
The circuit is closed only during operation.

The display circuit 53 has terminals 50A and 50B connected to the control device 30.
A bridge circuit 54 consisting of six diodes D1 to D6 forming a full-wave rectifier circuit and a switching circuit 55 are connected to the output side of the bridge circuit 54 so that the terminals 36 and 37 may be reversely connected. It consists of a combustion lamp circuit 56 and an operating lamp circuit 57 which are provided in parallel.

In the bridge circuit 54, the voltage applied between the terminals 50A and 50B is connected to the switching circuit 55 and the combustion lamp circuit 5.
6 and the operation lamp circuit 57, and the diode D3 and the diode D4,
Further, by connecting the diode D5 and the diode D6 in series, the rise voltage of the display circuit 53 is set high, and the current flowing to the display circuit 53 is reduced when the drive voltage to the display circuit 53 is not supplied.

The switching circuit 55 is a circuit for supplying lamp lighting power to the combustion lamp circuit 56 and the operating lamp circuit 57 when the voltage supplied from the bridge circuit 54 is equal to or higher than a predetermined voltage. transistor Q
When the voltage applied to Zener diode ZDI connected to the base of Zener diode ZDI exceeds the breakdown voltage of Zener diode ZDI, transistor Q1 and transistor Q2 are both turned on, and power is supplied to each lamp circuit 56, 57.

The combustion lamp circuit 56 is supplied with power for lighting the lamp from the switching circuit 55, and at that time, the diode D7
The DC voltage applied to the resistor R5 via the AC component includes an AC component, and when the AC component is equal to or higher than a predetermined voltage, the combustion lamp L1 made of a light emitting diode (LED) is turned on.

Here, the AC component of the DC voltage applied to the resistor R5 passes through the capacitor C1, is voltage doubled and rectified by the diodes D8 and D9, and is then charged to the capacitor C2 via the resistor R6. When the charging voltage of the capacitor C2 is above a certain voltage, the charge of the capacitor C2 flows through the resistor R7 as a base current to the transistor Q3, and at this time, the transistor Q3 is turned on, and the combustion connected to the collector of the transistor Q3 is turned on. Lamp L1 lights up.

The operating lamp circuit 57 lights the operating lamp L2 made of a light emitting diode when power for lamp lighting is supplied from the switching circuit 55 and the effective value of the DC voltage at that time is equal to or higher than a predetermined voltage.

Here, the switching circuit F#r5 is connected via the resistor R8.
When the potential of the capacitor C3 is higher than a predetermined voltage, the capacitor C3 is charged by the supply voltage from the resistor R9 and discharged by the diode D10 when the supply voltage is lower than the charging voltage.
A base current flows through the transistor Q4 to turn on the transistor Q4, and the operating lamp L2 connected to the collector of the transistor Q4 lights up.

Next, the sub remote control 60 will be explained.

The sub remote controller 60 has a terminal 60 as shown in FIG.
A variable resistance circuit 61 and a display circuit 63 are provided in parallel between A and 60B.

Similar to the variable resistance circuit 51, the variable resistance circuit 61 includes a variable resistor VR2 and a resistor R11 connected in parallel.
12, and a rotary priority switch SW2 is further connected in series to these. The priority switch SW2 is a switch for performing temperature adjustment control in the control device 30 based on the set temperature of the sub-remote controller 60. In the control device 30, when the priority switch SW2 is in the on state, the sub-remote controller 60 is selected. , the main remote controller 50 is selected when it is in the off state.

The display circuit 63 has the same configuration as the display circuit 53 in the main remote controller 50, and includes a bridge circuit 64 and a combustion lamp circuit provided in parallel to the output side of the bridge circuit 64 via a switching circuit 65 and equipped with a combustion lamp L3. 66 and an operating lamp circuit 67 including an operating lamp L4.
Further, on the output side of the bridge circuit 64, a priority display circuit 68 is provided in parallel with the switching circuit 65.

The priority display circuit 68 includes a display switch SW3 and a resistor R1.
3. The 0 display switch SW3, which is made by connecting priority lamps L5 made of light emitting diodes in series, is a rotary switch that works in conjunction with the priority switch SW2. When giving priority to the sub remote control 60, the priority switch SW3
2, the circuit is closed and the priority lamp L5 is turned on.

In the control device 30, when the control device 30 is connected to a power line, a 5V power supply (not shown) is always operating, and the microcomputer is operating in a standby state.

In the sequence control unit 31, when the control device 30 is connected to the power line, it is always in a startup standby state, and the resistor 4
1.41a respectively detected terminals 36.37
, and each terminal voltage between terminals 38 and 39 V50. A predetermined operating mode is determined based on V2O.

In the sequence control section 31, each terminal voltage V'jO1V6
(For l, as shown in Figure 5 or Figure 6, respectively, 0.5 to 2.5 V is read as the set temperature voltage, 3.5 to 5 V is read as the disconnection detection voltage, and 0.0
5V or less is read as a short circuit detection voltage between terminals 36 and 37 and between terminals 38 and 39.

Also, the terminal voltage on the main remote controller 50 side. For this, a voltage of 0.05 to 0.3 V, which is lower than the lowest voltage of 0.5 V read as the set temperature voltage and higher than 0.05 V as the short circuit detection voltage, is read as the operation switch operation voltage.

On the other hand, regarding the terminal voltage V6° on the side of the sub-remote controller 60, since 0.5 to 2.5V as the set temperature voltage is detected only when the priority switch SW2 is closed, the set temperature voltage The time when is detected is the time when the sub remote control 60 is used preferentially.

Conversely, when the priority switch SW2 is in the open state, the terminal voltage ■6° is higher than the set temperature voltage of 0.5~2.5■, so when 3.5~5V is detected, the main remote controller 50 When used.

In this way, when a voltage of 3.5 to 5V is detected for the terminal voltage V60, it cannot be determined whether it is due to a disconnection or the like or because the priority switch SW2 is in the open state, but in either case. Also, sub remote control 6
Since the setting state of the variable resistance circuit 61 of 0 has no bearing on control, there is no problem in practice.

The operation mode is determined by determining the connection state, conduction state, or short circuit state of each terminal voltage V, o, V6o, based on whether it is the disconnection detection voltage or the set temperature voltage set respectively as described above. It is determined by discrimination.

The operating modes include a multi mode in which the main remote controller 50 and sub remote controller 60 are both connected, an automatic mode in which neither remote controller is connected, and a single mode in which only the main remote controller 50 is connected. be.

In cases other than automatic mode, the sequence control unit 31
When an operation signal from the operation switch SWI is detected, the device enters a standby state, and in the automatic mode, the device is always in a standby state.

In the case of multi-mode, when the operation signal of the operation switch SWI is detected and the operation signal becomes standby, the priority switch S
Based on the terminal voltage V6° on the side of the sub-remote controller 60 equipped with W2, it is determined which remote controller is to be controlled based on the set temperature information, and the set temperature from the selected remote controller is transmitted to the temperature control controller 32. do.

In addition, in the operation standby state, the operation standby state and
The selected remote controller selection information is transmitted to the display control unit 35.

In the standby state, the power to the drive circuits for driving the blower 12 and multiple valves of the gas water heater 1 is turned on.
When water flow to the heat exchanger 13 is detected by the water flow switch 19, combustion is started by performing predetermined ignition sequence control, and when water flow stop is detected, combustion is stopped by fire extinguishing sequence control.

On the other hand, each terminal voltage V,. , ■6°, if a short circuit between each terminal is detected, it is assumed to be an abnormality detection state, and an abnormality display signal is sent to the remote controllers for which no short circuit has been detected. is selected, it operates as automatic mode.

When the temperature control unit 32 enters the operation standby state and the operation state, the temperature control unit 32 reads the set temperature voltage from the selected remote controller before the water flow is detected, and starts heating based on the temperature information detected by the outlet hot water temperature thermistor 25. The amount is determined and transmitted to the combustion control section 33.

Here, as shown in FIG. 12, the actual resistance value r of the variable resistor in the variable resistance circuit of the remote control is smaller than the standard maximum resistance value r0, and the resistance value rt ( Even if the resistance value r = standard maximum resistance value r. ' min is determined as the limit resistance value for setting, and as shown in FIG. The set temperature is set higher as the resistance value r of the variable resistor becomes smaller than the constant resistance value r2.

That is, when the resistance value r of the variable resistor is a constant resistance value r2, the constant voltage V given as the terminal voltage of the remote control
In the case of 2 or more, the set temperature is set as the lowest temperature Train, and as the terminal voltage becomes lower than the constant voltage 2, the set temperature is set higher.

Note that this constant voltage V2 is 2, which is shown as the highest voltage as the set temperature voltage in FIGS. 5 and 6.
The voltage is lower than 5V, and the terminal voltage becomes 2.5V when the resistance value is r. Further, the maximum temperature TlaX of the set temperatures is set when the terminal voltage is 015v.

As a result, as shown in Fig. 14, in the remote control,
Slide-type variable resistor ■Out of the movement range E of the knob B that moves with the contact of R, the end F on the side with a larger resistance value
In the side part e, the lowest temperature Tm1n (35℃
) is set, and in areas other than this portion C, the set temperature gradually increases as the temperature moves away from the end F and toward the other end G.

In automatic mode, the system is always on standby, and when water flow is detected, the temperature is set to a certain level (e.g. 60'C or 75'C).
℃〉 as the set temperature, and in the single mode, it is in a startup standby state, and operates only in response to the operating state of the main remote controller 50, similar to when the main remote controller takes priority in the multi-mode described above.

The combustion control section 33 controls the blower 12 and the governor proportional valve 23 according to the heating amount determined by the temperature control section 32 to control the combustion amount of the burner group 11 .

The display control unit 35 controls each lamp of each remote controller 50, 60 in three types: on, off, and blinking based on the information of the selected remote controller and the combustion information detected by the flame rod 15, depending on the respective operating conditions. Control signals for controlling each of these are sent to remote control drive circuits 40 and 40a, respectively.

Before explaining the control contents of the display control section 35, the remote control drive circuit 40.40 controlled by the display control section 35 will be described.
The configuration of a will be explained.

In the remote control drive circuit 40.40a, the supply voltage from the 5V power supply is applied to each terminal 36.38 via a resistor 42.42a.
and is constantly supplied as a detection voltage v rem to each remote control 50 , 60 connected to each terminal 36 , 38 .

The remote control drive circuit 40.40a has a detection voltage v r
In addition to em, 5V@, DC voltage from the source is applied to each terminal 36.
Switching transistors 43.43 to directly supply voltage to each remote control 50.60
a is connected to each terminal 36.38 through a diode 44.44a.
is connected to.

Furthermore, in order to directly supply DC voltage from a 12V power supply (not shown) to each remote controller 50, 60, switching transistors 45, 45a are connected to each! ? It is connected to 36.38.

Note that a switching transistor 46.46a is provided before the transistor 45.45a, and each transistor 43.43a, 46.46a is connected to the display control unit 35.
each controlled by

In the remote control drive circuit 40, each switching transistor 43.45 applies a respective voltage to the terminal 36 only when turned on by a control signal, and when both transistors 43.45 are turned off, voltage is applied from the 5V power supply. Only the voltage V rate is applied to the terminal 36 via the resistor 42 as the detection voltage v rate.

When the transistor 43 that directly supplies power from the 5V power source and the transistor 45 that directly supplies power from the 12V power source are both off, the detection voltage v re + a from the power source is determined by the variable resistance in the main remote controller 50. It is applied to a series circuit consisting of the parallel circuit of the circuit 51 and the operation switch circuit 52 and the resistor 42, and the voltage is applied to the terminal 36.
Depending on the operating state of the variable resistance circuit 51 in the main remote controller 50, the terminal voltage V is determined according to the combined resistance.
,. Appears as.

Similarly to the remote control drive circuit 40, when the respective voltages are applied to the remote control drive circuit 40a and both the transistors 43a and 45a are off, the terminal 7-
38, a voltage corresponding to the operating state of the remote controller 60 appears as a terminal voltage V66.

The display control section 35 controls each remote control 5O160 according to the control state of the sequence control section 31 via the remote control drive circuit 40.40a configured as described above.

The lighting, blinking, and extinguishing of each lamp is controlled depending on the operating status of the gas water heater 1: whether it is in standby mode, whether it is in combustion mode, and whether an abnormality is occurring. Further, a separate display is performed for each remote controller 50, 60 depending on whether or not that remote controller is in a priority state.

The relationship between the display state on each remote controller 50, 60 and the operating state of the gas water heater 1 is summarized in Table 1.

From Table 1 onwards, the control of the remote control drive circuit 40 by the display control section 35 will be explained. Note that the remote control drive circuit 40a is described in parentheses (>).

■When lighting only the operation lamp L2 (L4) without lighting the combustion lamp LX (L3), turn on the transistor 45 (45a) and
Power from the 2V power supply is supplied almost continuously.

In this case, since the set temperature signal is read from the remote controller that receives this control, the power supply from the 12V power supply is stopped for a short period of time, and only the detection voltage v rem is supplied from the 5V power supply. The time is set at intervals of 30m5, each BmS.

■When only the operation lamp L2 (L4) blinks without lighting the combustion lamp LL (L3), turn on and off the transistor 45 (45a) according to the blinking cycle, and turn on the 12V power supply as shown in Figure 8. Provides intermittent power from the At this time, the blinking cycle is, for example, 2.7Sf.
IC is turned on and turned off for 2.7 seconds.

■Combustion lamp LL (L3) and operation lamp L2 (
When both transistors L4) are turned on, the transistor 43
(43a) is turned on to continuously supply power from the SVt source, and the transistor 45 (45a) is controlled to turn on for 5 mS and off for 5 mS, for example, with a continuous constant pulse with a pulse period of 10 m5. This is repeated, and as shown in FIG. 9, the power from the 12V power supply converted into pulses is supplied superimposed on the power from the 5V power source.

In this case as well, the time period during which both the power from the 5V power source and the power from the 12V power source are stopped and only the detection voltage vre- is supplied is provided at intervals of 30 m5, each BmS.

■If only the combustion lamp Ll (L3) is lit continuously and the operation lamp L2 (L4) is blinked,
For example, as shown in FIG. As shown in
5. Control the power from the power supply so that it changes according to the blinking cycle.

■If you want to blink only the combustion lamp LL (L3) without lighting the operation lamp L2 (L4), fix the transistor 43 (43a) to OFF and stop the power from the power source. As shown in , the pulse period is 10
The power from the 12V power source converted into continuous constant pulses of m5 is supplied intermittently in accordance with a blinking cycle in which, for example, I5eC is turned on and ISeC is turned off.

Transistor 43 that directly supplies power from the 5V power supply
(43a>) and the transistor 45 (45a) for directly supplying power from the 12V power supply are both off, and when only the detection voltage Vrel from the 5V power supply is continuously supplied, the combustion lamp Ll (L3 ) and operation lamp L2 (L4) do not light up.

In addition, in each of the cases of ■ to ■ above, even if each lamp is lit or blinking, the remote control 50
In order to be able to read the operating state of (60), as in the case of (2), the time during which only the detection voltage vrc- is supplied from the 5V power supply is increased by 3mS for 30m
They are provided at 5 intervals.

In this case, since the time during which only the detection voltage V rQl is supplied is a very short time of 3 mS, each lamp can be lit and blinked without any visual problem.

Note that in the sequence control section 31 described above, the terminal 36
．． If 0.05V or less is detected as the short circuit detection voltage between 37 and 37, control is performed so that each transistor 43.45 in the remote control drive circuit 40 is not turned on in order to protect each transistor 43.45 from damage etc. to stop power supply.

Similarly, the short circuit detection voltage between terminals 38 and 39 is 0.0.
If 5V or less is detected, the remote control drive circuit 40
The power supply by each transistor 43a, 45a in a is stopped.

The water flow control unit 34 controls the electric water flow control device 18 based on the temperature information detected by the outlet hot water temperature thermistor 25 to limit a flow rate exceeding the heating capacity from passing through the heat exchanger 13 .

Next, the temperature setting operation in the gas water heater 1 of this embodiment having the above configuration will be explained.

The operation mode is determined according to each terminal voltage, and when the operation switch SWI is operated to enter the operation standby state, the detection voltage V is sent to the selected remote controller at one research cycle as shown in FIG. When only REM is applied and each lamp is lit or blinking, if the user sets the hot water temperature using the variable resistance circuit of the selected remote control, the terminal voltage will change according to the resistance value of the variable resistance circuit. Read as set temperature signal.

At this time, if the resistance value of the variable resistor is greater than the constant resistance value r2, the lowest temperature becomes the set temperature, and if it is less than that, the lower the resistance value, the higher the temperature is set according to each resistance value. Ru.

At this time, a detected temperature signal is also read from the outlet hot water temperature thermistor 25, and the combustion amount is determined using these as heating information. .

Thereafter, when a hot water tap (not shown) is opened, ignition is performed in a predetermined sequence, and the burner group 11 is ignited.

After ignition, when you operate the variable resistor on the remote control, a new hot water temperature is set according to the resistance value.

At this time, in the variable resistor VR of the remote control shown in FIG.
The minimum temperature Tn+in can be set within a predetermined range e from 1 to 2, and the set temperature can be increased when the range e is exceeded.

As a result, for example, when changing the lowest temperature Tm1n (35°C) to about 38°C, turn the knob B of the variable resistor VR from the end F to the opposite end G at about 38°C.
It is only necessary to move the temperature inward to the vicinity of the schematic diagram that indicates the movement, and the amount of movement is such that the degree of change can be easily adjusted manually, making it easy to change the set temperature. .

In addition, when using a remote control to display a specific temperature in numbers instead of a schematic diagram showing a shower or a diagram M showing a bath as shown in Figure 14, these displays are displayed at appropriate intervals. This arrangement is also aesthetically effective.

In this example, the supply voltage to the variable resistor was supplied through the resistor, and the voltage at the connection was detected and set as the set temperature voltage, but the voltage from the power supply section was directly supplied to the variable resistor. A resistor may be provided to allow the current that has passed through the variable resistor to flow to the ground circuit, and the voltage divided into this resistor may be used as the set temperature voltage.

In this embodiment, a sliding type variable resistor is shown, but a rotating type variable resistor may also be used.

In this embodiment, water flow is detected by the water flow switch, but water flow may be detected by a flow rate detection signal from a flow rate sensor.

In the above embodiments, a gas water heater is shown, but it may also be a water heater equipped with a combustor that uses other fuels such as oil, or a water heater that uses electric heating, or a water heater that is equipped with a variable resistor for temperature setting. Any temperature control device may be used.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the functional configuration of the control device for the gas water heater of this embodiment, Fig. 2 is a schematic configuration diagram showing the gas water heater of this embodiment, and Fig. 3 shows the main remote control of this embodiment. 4 is a circuit diagram showing the sub-remote controller of this embodiment, FIG. 5 is a voltage explanatory diagram showing the discrimination voltage for the main remote controller in the control device of this embodiment, and FIG. 6 is a control diagram of this embodiment. A voltage explanatory diagram showing the discrimination voltage applied to the sub-remote controller in the device, Figures 7 to 11 are voltage waveform diagrams for lighting the lamps of each remote controller, and Figure 12 is the contact position of the variable resistor in this example. FIG. 13 is a characteristic diagram showing the relationship between the resistance value and the resistance value of the variable resistor in this example, and the characteristic diagram showing the relationship between the terminal voltage and the set temperature.
FIG. 4 is a plan view showing an example of a variable resistor portion of the remote control. In the figure, 1... Gas water heater (water heater), 30... Control device (temperature control device for water heater), 50... Main remote control (operation unit), 51... Variable resistance circuit, R1 ...variable resistor. Agent Kenji Ishiguro Figure 5 Figure 6 Figure 14 Figure υ Figure 7 Figure 8 Figure 9 Sub-O figure Figure 11 Figure 12 rl! J Resistance Housework Movement Range Resistance Value Large Contact Location Figure 13 Resistance Value of Variable Resistor

Claims (1)

[Scope of Claims] 1) Temperature control of a water heater that is equipped with a variable resistor that shows a resistance value depending on the contact position of a contact point to a resistor, and that sets a target temperature according to the set resistance value of the variable resistor. In the apparatus, when the set resistance value is equal to or higher than a certain resistance value, the temperature is set to the lowest temperature that can be set, and the smaller the set resistance value is, the higher the target temperature is set. Water heater temperature control device.