JPS6331708B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion control circuit in which temperature control for both hot water supply and space heating can be performed using one temperature sensing element.

In conventional combustion control circuits of this type, water temperature control during hot water supply is affected exponentially by the resistance-temperature characteristics of the thermosensor, and the water temperature does not change proportionally to the control. That is, as shown in FIG. 2b, the temperature of the hot water changes little in the X region due to the rotation of the knob, but changes rapidly in the Y region. On the other hand, this temperature sensing element also controls the temperature of hot water for heating.

Therefore, it is necessary to improve the characteristics of the temperature sensing element so that the hot water temperature can be changed proportionally to the hot water temperature control during hot water supply. It was necessary to take care not to adversely affect the temperature of the hot water used for heating.

The present invention makes it easy to use during hot water supply and space heating by making the hot water temperature control using a variable resistor during hot water supply proportional to the change in the temperature of the hot water being dispensed. It is intended to improve

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

1 is a DC power source consisting of a power transformer, a rectifier circuit, and a power capacitor; 2 is a switch that operates by detecting pilot flame combustion; 3 is a heating switch; 4 is a heating switch;
The hot water switch 4 and the hot water tap are linked so that when the hot water tap is opened with the hot water tap, the hot water tap 4 is closed, and when the hot water tap is closed, the hot water tap is opened. Reference numeral 5 denotes a solenoid valve configured to control the amount of gas passing by using an energized current, 6 a temperature sensing element (thermistor) that senses the temperature of the hot water, and 7 a current applied to the solenoid valve 5 in response to a signal from the temperature sensing element 6. 8 is a fixed resistor for making the hot water temperature change of the variable resistor into an equal scale with the parallel resistance of the temperature sensing element 6; 9 is a fixed resistor for adjusting the hot water temperature. The variable resistor 10 is a fixed resistor that determines the O ohm (minimum water temperature) of the variable resistor 9. 11 is a diode for preventing malfunction. 12, 13,
Fixed resistors 14, 15, 16, 17, and 18 provide bias to transistors 19 and 20 for operating the next transistors 19 and 20. 19 and 20 are transistors that perform a switch operation.

In the proportional control circuit 7, 21 is a diode for preventing reverse voltage of the solenoid valve 5, 22 and 23 are fixed resistors, 24 and 25 are diodes, 26 is a transistor, 27, 28, 29, and 30 are fixed resistors, and 31
is a transistor, 32 and 33 are fixed resistors, and 34
is a transistor, 35 is a fixed resistor, 36 is a fixed resistor, 37, 38 are transistors, 38, 3
9, 40 are fixed resistors, 41 is a capacitor, 42
is a transistor, 43 is a fixed resistor, 44 is a transistor, 45 is a fixed resistor, and 46 is a return resistance. 47 is a diode. The proportional control circuit 7 is configured as described above.

48 is a constant voltage diode. 49 is a diode.

Next, the operation will be explained.

By using the DC power supply 1 as a power source and igniting the pilot flame by some means by operating the gas stove,
Upon detection of pilot flame combustion, switch 2 is turned on, and the combustion device becomes ready for operation.

Next, when the heating switch 3 is turned on, power is supplied to the constant voltage diode 48 through the resistor (fixed resistor) 22, and constant voltage power is supplied to both ends of the diode 48.

To explain the operation of the proportional control circuit 7, the resistance 23 is
and diodes 24, 25, temperature sensing element 6 and its parallel resistance 8 and resistance 12 (transistor 19 is biased by resistances 13, 14 and 15 and operates as a switch and its emitter-collector voltage is approximately zero).transistor 20 Since no voltage is applied to the base and it is in the off state, its emitter-collector voltage is equal to the voltage of the constant voltage diode). The transistor 26 is turned on and off by changing the resistance value of the temperature sensing element 6, which is one side of the bridge circuit made up of resistors 28, 29, and 30. Therefore, the resistance value of the temperature sensitive element 6 increases until the set point at which transistor 26 turns on, turning on transistor 26 and turning off transistors 31 and 34. Further, the current flowing through the transistor 26 increases through the resistor 27 depending on the resistance value of the temperature sensing element 6, and the current amplified by the resistor 27 is passed through the resistors 29 and 3.
flows to

Transistors 37 and 38 provided in the bridge circuit of resistors 28, 29, 30 and 39, 40 constitute a differential amplifier, and as the voltage across resistors 29 and 30 increases, transistor 37 is turned off. At the same time, transistor 38 turns on and resistor 3
The current flowing through 8a increases. When the voltage V _BE of transistors 42 and 44 is exceeded, transistors 42 and 4
4 is turned on, the solenoid valve 5 is energized, and the return resistor 46 is turned on.
detects the current flowing through the solenoid valve 5, and connects the resistor 40
Detects fluctuations in the voltage across the transistor 38 and controls the current flowing to the resistor 38a through the transistor 38. Therefore, the current flowing to the resistor 38a is controlled in proportion to the rise and fall of the resistance value of the temperature sensing element 6, and the current flowing through the transistor 4 is controlled.
2 and 44 to control the current to the solenoid valve 5.

Here, if the hot water tap is opened, hot water switch 4 is turned on. Since voltage is supplied to resistors 17 and 18, transistor 20 is turned on. Since the operation is a switch operation, the emitter-collector voltage of the transistor 20 is approximately ^Ov .

Therefore, the voltage between the base and emitter of transistor 19 becomes 0.6V or less, so transistor 19
9 turns off and at the same time the current flows through the temperature sensing element 6 and the resistor 8.
From variable resistor 9, resistor 10, diode 11
It flows. It flows from the single-point control for heating to the multi-point control transistor 20 for hot water supply.

Now, if variable resistor 9 is set to OΩ and shorted, this will be the voltage across resistor 10 and diode 11.
The sum of V _F and V _CE (sat) of transistor 20 is
Let it be _Vwnio . Let V _H be the sum of the voltage across the resistor 12 during heating, which is V _wnio , and V _CE (sat) of the transistor 19. V _wnio ≪Since V _H and resistor 10 are selected,
The temperature sensing element (thermistor) 6 has a large resistance value, that is, performs proportional control at low temperatures.

Next, to set the variable resistor 9 to the maximum resistance value, it is sufficient to add the voltage across the variable resistor to V _wnio , and this is set as V _wnax . Since the resistance value of the variable resistor is selected as V _wnax ≒ V _H , the temperature sensing element thermistor 6 performs proportional control with a small resistance value (high temperature).

FIG. 2a shows an example where a resistor 8 is present, and the water temperature changes uniformly by rotating the knob. FIG. 2b shows an example without the resistor 8, in which the temperature of the hot water changes little in the X region, but changes rapidly in the Y region.

In this way, hot water temperature control by the variable resistor 9 during hot water supply can be performed proportionally by connecting the resistor 8 in parallel with the thermistor 6, eliminating the exponential effect of the resistance-temperature characteristic of the thermistor 6. .

On the other hand, when controlling the warm water temperature, the thermistor 6 and the resistor 8 are connected in parallel to eliminate the exponential effect of the resistance-temperature characteristic of the thermistor 6, but the entire characteristic is at a low position, and the high temperature Heating hot water will no longer be available. Therefore, in the present invention, a resistor 1 whose resistance value is set so as to obtain high temperature hot water is used.
A transistor 19 serving as a switching element for heating is connected to the parallel circuit through the transistor 2. In this way, as mentioned above, the sum V _H of the voltage across the resistor 12 and the V _CE of the transistor 19 is
This becomes extremely larger than _Vwnio , and the current flowing to the proportional control circuit 7 becomes large, so that the solenoid valve 5 can be opened wide to increase the amount of gas supplied to the burner, and high-temperature heating hot water can be obtained.

With the above configuration, the present invention has the following effects.

(1) It is an energy-saving type that can adjust the temperature of hot water and only supplies the required temperature.

(2) The hot water temperature control circuit uses the switching characteristics of semiconductors, so it is highly reliable and has a long life.

(3) It is inexpensive because it uses one pipe and two channels, and one temperature-sensitive element controls heating and hot water supply.

(4) A single thermosensor is used to control the hot water temperature for heating and hot water supply, but the heating water can be heated to a high temperature, and the hot water temperature can be uniformly changed in proportion to the control of the variable resistor.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a combustion control circuit according to an embodiment of the present invention, and FIGS. 2a and 2b are diagrams showing the relationship between the temperature adjustment knob and temperature. 3... Heating switch, 4... Hot water switch, 5
... Solenoid valve, 6 ... Temperature sensing element, 7 ... Proportional control circuit.

Claims (1)

[Claims] 1. In a device that controls the temperature of both hot water supply and heating with one temperature sensing element, a solenoid valve that controls the fuel supplied to the burner, the above-mentioned temperature sensing element that senses the temperature of the heating water, and this temperature sensing element a proportional control circuit that controls the amount of energization of the solenoid valve to control the combustion amount of the burner in response to a signal; a switching element for hot water supply that operates in response to a hot water supply signal; and a switching element for heating that operates in response to a heating signal; In this heating switching element, a resistor is connected in parallel to a temperature sensing element whose one end is connected to the proportional control circuit, and a fixed resistor is connected in series to this parallel circuit. is a combustion control circuit comprising a variable resistor for regulating hot water temperature connected in series to the parallel circuit.