JPS586171B2 - Denki Danbouki - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses the temperature characteristics of a thermistor to automatically
To provide an electric heater in which conduction of a second heater is controlled to effectively generate heat within a range of total calorific value.

Recently, a radiant heating system known as an electric stove and a fast heating type heating system known as an electric warm air fan have been incorporated into a single device.
A so-called composite electric heater that effectively utilizes the advantages of each heating method has been proposed.

The total power of such a combined electric heater is determined as the sum of the wattage of the radiant heater and the hot air heater.

For example, if the wattage of each heater is 600W, when both heaters are used at the same time, the output is 1.2KW, and when only one heater is used, the output is 600W.

Therefore, for example, even if it is desired to perform rapid heating using only a hot air heater, the heater can only be used at a low wattage of 600W, even though the total wattage of this heater is 1.2KW, and the heater cannot be used effectively.

Furthermore, even when using both heaters, the heater switching is done manually, so even though there is a heating power method depending on the room temperature, it is usually used with both heaters turned on due to the inconvenience. This is not desirable in terms of power consumption.

In view of this, the present invention sets the wattage of each heater to be equal to or close to the total wattage of this heater (for example, 1.2KW), and when both heaters are used at the same time, the wattage of each heater is By halving the conduction time of the rectifying elements with control poles connected in series, the heat generation amount of each heater is halved (600
W), the total wattage is kept within the allowable wattage of the heater, and when only one heater is used at low temperatures, the energization of the other heater is suppressed.
Moreover, the switching of the heaters is automatically performed using a thermistor.

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

Figure 1 is a front view of the electric heater.The first heater H1, which serves as two radiant heaters, is placed in front of the reflector plate at the top of the front, and the first heater H1, which serves as a hot air heater, is located at the bottom of the main body. 2 A hot air generating device consisting of a heater H2 and a blower M is housed, and a hot air generating device consisting of the hot air fan M is housed therein, and the warm air is discharged from an outlet provided at the lower front. There is.

FIG. 2 is a circuit diagram of FIG. 1, and the same components as in FIG. 1 are denoted by the same reference numerals.

In the figure, each heater H17H2 is connected in series to separate bidirectional rectifiers with control poles (hereinafter referred to as first and second triacs) TR1 and TR2 to form first and second series circuits 2 and 3. The first and second series circuits 2 and 3 are connected to an AC power source E.

The control poles of the first and second triaxes TR1 and TR2 are the first
, a second constant voltage conduction element (hereinafter referred to as diac) D1,
It is connected to the first and second control signal circuits 4 and 5 via D2.

The first control signal circuit 4 includes positive and negative thermistors TH1, T
The second control signal circuit 5 consists of a series circuit of a thermistor TH2 and a capacitor C2, and both circuits 4 and 5 are connected to a fixed resistor H.

Next, before explaining the operation of the first and second control signal circuits 4 and 5, the operation of a series circuit of a resistor and a capacitor will be considered.

It is generally well known that when alternating current is supplied to a series circuit consisting of a resistor and a capacitor, a current flows through the circuit.

This leading current causes the counter electromotive voltage generated across the resistor to lead in comparison to the phase of the power supply voltage.

For example, in FIG. 2, an AC voltage is applied via a fixed resistor R to a first control signal circuit 4 consisting of thermistors TH1 and TH3 and a capacitor C1, and a second control signal circuit 5 consisting of thermistor TH3 and a capacitor C2. When applied, a back electromotive force is generated as shown in the vector diagram of FIG.

If the resistance of the thermistors TH1 and TH3 of the first control signal circuit 4 is RltR3, and the combined resistance is R13, the back electromotive force vR13 advances by a phase angle ψ13 with respect to the voltage e of the AC power supply E, and the back electromotive force generated in the capacitor C1 The voltage VCI is (
The phase is delayed by 1/2-ψ13).

Similarly, if the resistance of the thermistor TH2 of the second control signal circuit 5 is R2, the back electromotive force VR2 advances by a phase angle ψ2 with respect to the voltage e of the AC power supply E, and the back electromotive force V of the capacitor C2
C2 is delayed by (T/2-P2).

If ψ2 is R13=R for ψ13, and +R3>R2, the relationship becomes ψ2>ψ13 as shown in Figure 3, and R13=R1
If +R3 - R2, the relationship becomes ψ2 - ψ13 and R13
=R1+R3〈If R2, contrary to Fig. 3, ψ2〈ψ1
There will be a relationship of 3.

Thermistors THr, TH2, and THs have resistance values that change depending on the temperature, and each thermistor TH1tTH2t
The temperature characteristics of TH3 change as shown in FIG.

In the figure, the horizontal axis shows the temperature T, and the vertical axis shows the resistance RTH.

Since the resistances RltR3 of thermistors TH1 and TH3 exhibit positive and negative temperature characteristics, their combined resistance R13 is high at low temperatures T1, decreases once at medium temperatures T2 and T3, and decreases once at high temperatures T4, as shown in the figure. will rise again.

On the other hand, since the resistance R2 of the thermistor TH2 exhibits positive temperature characteristics, its resistance value also increases as the temperature rises.

When the thermistors TH1, TH2, TH3 change with temperature as described above, the back electromotive voltages C1, VC2 of the capacitors C1, C2 of the first and second control signal circuits 4 and 5 change, and the first and second diamonds DI change. ? Through D2, the conduction periods of the first and second triaxes TR1 and TR2 are controlled, and the amount of heat generated by the first and second heaters H1 and H2 is controlled.

First, when examining the operation at low temperature T1, the thermistor TH
1, the combined resistance R13 of TH2 is large, and the thermistor TH
2, the resistance R2 is small.

Therefore, the back electromotive force VC1 of the capacitor C1 of the first control signal circuit 4 is small and has a phase lag (7/2-ψ13).
is large (Fig. 5 A).

Assuming that the breakdown voltage of the first and second dials D1tD2 is VD, as shown in FIG. conduction between the two.

(Figure 5c). On the other hand, thermistor TH2 has low resistance,
Back electromotive force VC2 of capacitor C2 of second control signal circuit 5
is large and the phase lag (7/2 - ψ2) is small, so the second diode D2 breaks down at point b due to the back electromotive voltage vc2, making the second triac TR2 conductive between 11 and 13 (see Figure 5).

As described above, at low temperatures, the conduction period of the second triac TR2 is longer than that of the first triac TR1, so the calorific value of the second heater H2 is greater than the calorific value of the first heater H1, resulting in rapid heating due to hot air. suitable for doing.

When the room temperature rises to medium temperature T2, T3, thermistor T
The combined resistance R13 of H1 and TH3 becomes smaller and the resistance of thermistor TH2 becomes larger and equal or thermistor T
Conversely, the resistance R2 of H2 becomes higher.

For this reason, the amount of heat generated by the first and second heaters HltH2 is the same, or the amount of heat generated by the first heater H1 increases, and the heat generated by the first heater H1, which is a radiant heater, is also observed by the user, so it looks warmer. It feels large and has a high visual heating effect.

When the temperature T4 becomes higher, both the combined resistance R13 of the thermistors TH1 and TH3 and the resistance R2 of the thermistor TH2 become higher, so the amount of heat generated by the first and second heaters HltH2 decreases.

In the above example, the first control signal circuit 4 controls the operation of the second heater H2, and the second control signal circuit 5 controls the operation of the second heater H1, but the operation can also be reversed.

In this case, at low temperature T1, the first heater H1, which is a radiant heater, is operated by the second control signal circuit 5, so the visual heating effect is high, but the second heater H2, which is a warm air heater, is operated by the second control signal circuit 5.
Rapid heating is difficult because the system stops working.

In the above example, the back electromotive voltages Vc1 and Vc2 of the capacitors C1 and C2 of the first and second control signal circuits 4 and 5 are taken out and used as control signals, but the fixed resistor R is used as a capacitor, and the capacitors C1 and C2 are used as resistors. Although it is also possible to use the back electromotive force of the resistor, it is necessary to note that the phase relationship is different from the above example.

Further, in the above example, a bidirectional rectifying element with a control pole is used, but it goes without saying that the same effect can be achieved even if a unidirectional rectifying element with a control pole is used.

As described above, the present invention connects the first series circuit of the first heater and the rectifier with a first control pole to an AC power supply, and connects the first constant voltage element to the control pole of the rectifier with the first control pole. A first control circuit consisting of a positive and negative thermistor and a capacitor is connected through the AC power source, and a second series circuit of a second heater and a rectifying element with a second control pole is also connected to the AC power supply. A second control signal circuit consisting of a positive thermistor and a capacitor is connected to the control pole of the rectifying element via a second constant voltage element to automatically control conduction of the first and second heaters according to temperature changes. By appropriately determining the thermistor and the capacitor, only one heater will primarily generate heat at low temperatures within the range of the heater's total heat output, increasing the heating effect.
At medium temperatures, both heaters generate heat in a well-balanced manner to enhance the visual heating effect, and at high temperatures, both heaters stop generating heat to prevent unnecessary power consumption.The thermistor automatically selects and controls the heaters depending on the temperature. There is no need to switch.

[Brief explanation of the drawing]

Fig. 1 is a front view of the electric heater of the present invention, Fig. 2 is the circuit diagram of Fig. 1, Fig. 3 is a vector diagram for explaining operation, Fig. 4 is a diagram showing the temperature characteristics of the thermistor, Fig. 5 A, C and A are waveform diagrams for explaining the operation. H1 is a first heater, H2 is a second heater, TR1 is a rectifier with a first control pole, TR2 is a rectifier with a second control pole, 4 is a first control signal circuit, and 5 is a second control signal circuit.

Claims (1)

[Claims] 1 A first series circuit of a first heater and a rectifying element with a first control pole is connected to an AC power supply, and positive and negative voltages are connected to the control pole of the rectifying element with a first control pole through a first constant voltage element. A first control signal circuit consisting of a thermistor and a capacitor is connected, and a second series circuit of a second heater and a rectifier with a second control pole is also connected to an AC power supply, and the rectifier with a second control pole is connected. A second control signal circuit consisting of a positive thermistor and a capacitor is connected to the control pole via a second constant voltage element to automatically control conduction of the first and second heaters according to temperature changes. An electric heater.