KR910006844Y1 - 100v/200v free voltage control device for heating system - Google Patents

Abstract

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Description

110V / 220V combined thermostat

1 is a block diagram showing the basic configuration of the present invention.

2 is a detailed circuit diagram according to one embodiment of the present invention.

3A is a perspective view showing the structure of a heat generating unit.

Figure 3b is a graph showing the resistance-temperature of the thermosensitive ts.

4A and 4B are explanatory diagrams showing the relationship between the detection voltage V _S , the reference voltage V _R , and the trigger point P _L (P _H ).

* Explanation of symbols for main parts of the drawings

1: heat generating unit 2: temperature sensing circuit

3: voltage variable circuit 4: voltage detection circuit

5: comparison and trigger circuit 6: output circuit

7, 8: safety circuit 9: lamp

11 heater 12 sensing wire

13: heat-sensitive layer V _S : detection voltage

V _R : reference voltage V _E : power supply voltage

SF, TF: Fuse SCR: Silicon Controlled Rectifier

The present invention relates to a thermostat for both 100V and 220V, and more particularly, to a thermostat configured to always consume a constant power even if any power supply voltage is input in an electric blanket or an electric yaw. .

As is known, two types of voltages, 100V and 220V, are currently used as household voltages. Therefore, in order to use a certain electric appliance for both of these two types of voltages, a method in which a power supply voltage switching switch is used to set a predetermined voltage before use of the electric appliance is often used. However, in this case, it is not only inconvenient to set the changeover switch manually by human hands, but if the changeover switch is misaligned and excessive voltage or voltage is supplied, the parts may be damaged or the device may not operate. there was.

In addition, although an electric appliance (particularly a television) which is intended to be used at both 100V and 220V by using a relay without using such a switching switch is also known, the relay driving circuit is complicated in such a conventional apparatus. Not only could not be miniaturized, but the manufacturing cost was expensive.

The present invention is to solve the conventional problems as described above, the main purpose of the present invention is to adopt a half-wave phase controlled intermittent constant voltage circuit to minimize the change in power consumption to the change in power supply voltage to the voltage change between 90V to 240V The company intends to provide a thermostat in which the load always delivers constant power without a separate voltage change switch or relay.

Another object of the present invention is to provide a thermostat for use in an electric blanket or electric yaw, which provides a constant temperature by using only a constant power even if any power supply voltage between 90V and 240V is applied. Is to provide.

Another object of the present invention is to provide a thermostat of the type described above, which is simple in structure and inexpensive to manufacture.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a block diagram showing the basic configuration of the present invention, as shown in the circuit configuration of the present invention, the heater is a heating element and the temperature control unit for controlling the temperature of the heater, the heating unit ( 1), a voltage variable circuit 3 including a temperature sensing circuit 2, a reference voltage selection circuit, a voltage detection circuit 4, a comparison and trigger circuit 5, an output circuit 6, It can be divided into safety circuits (7) and (8).

As will be described in detail later, the heat generating unit 1 has a heater for providing heat required by an electric blanket or an electric yoke, and the voltage variable circuit 3 has a predetermined reference voltage V _R regardless of the power supply voltage. It includes a reference voltage selection circuit for maintaining this.

The voltage variable circuit 3 is a circuit for changing the trigger point according to the variable amount by varying the applied reference voltage V _R. Such a reference voltage selection circuit preferably uses one or more zener diodes, which are known in the art for the characteristics of the zener diodes. The temperature sensing circuit 2 detects the temperature variation of the thermal line, which is also located in the heat generating unit 1, and serves to transfer it to the comparison and trigger circuit 5. On the other hand, the voltage detection circuit 4 is a circuit for detecting a change in the power supply voltage, and the voltage detection circuit 4 measures the half wave detection voltage V _S at a specific point. The comparison and trigger circuit 5 accepts all of the above-described reference voltage and detection voltage, compares them, and generates a trigger pulse only when the reference voltage is higher than the detection voltage to trigger the output circuit 6. The output circuit 6 finally serves to energize the heater, and preferably includes an SCR.

FIG. 2 is a circuit according to an embodiment of the present invention shown in block diagram in FIG. 1, in which FIG. 2 specifically shows electrical elements for realizing each block of FIG.

Hereinafter, each component of the present invention will be described in detail. The heating unit 1 may include a primary winding (ie, heater) 11 and a secondary winding (ie, a sensing line) as shown in FIG. 3A. (12) and the heat-sensitive layer (13).

The heat-sensitive layer 13 is made of a conventional nylon thermistor. The thermosensitive layer 13 has a negative temperature coefficient characteristic in which the resistance Rz decreases as the temperature increases, and the resistance Rz increases when the temperature decreases (see also 3b). Reference numeral 14 denotes an outer shell.

The temperature change in the heat generating unit 1 is sensed by the temperature sensing circuit 2, that is, the temperature detecting circuit 2 senses the rise or fall of the temperature in the heat generating unit 1 and compares and triggers the circuit. (5) serves to deliver. Referring to FIG. 2, the temperature sensing circuit 2 includes the resistors R104 and R105 connected to the heater 11 and the sensing line 12, the diodes D201, and the capacitors C307 and C308. It can be considered that it consists of.

In addition, as described above, the temperature change of the heat generating unit 1 sensed by the temperature sensing circuit 2 is transmitted to the voltage variable circuit 3. That is, for example, when the temperature rises, the resistance of the heat sensitive layer 13 decreases accordingly, thereby increasing the amount of current flowing out from the sensing line 12 to the heater 11. At this time, since the voltage drop V ₁ across the variable resistors VR101 and VR102 and the resistor R104 in FIG. 2 increases, the reference voltage V _R at the point A decreases. As such, when the reference voltage V _R decreases, as shown in FIG. 4, the trigger point of the comparison and trigger circuit 5 (to be described later) is lowered, and thus the power supplied to the heater is reduced to reduce the temperature. It will prevent the rise. On the contrary, the temperature is lowered, and thus the power supplied to the heater is reduced to prevent the temperature from rising. On the contrary, when the temperature is lowered, the voltage drop V ₁ decreases as the resistance of the heat-sensitive layer 13 increases, thereby increasing the reference voltage V _R , thereby increasing the trigger point, thereby increasing power consumption. And the temperature rises. The voltage variable circuit 3 including the reference voltage selection circuit is configured to perform such a role, and includes a resistor R103, a variable resistor VR102, a VR101, a diode D202, and a D203. At this time, the diode D203 is composed of a control diode. Therefore, the reference voltage selection circuit always supplies a constant voltage to the circuit by the zener diode D203 even when the power supply voltage changes, so that the trigger point can be kept constant. The voltage variable circuit 3 adjusts power and temperature by varying the reference voltage V _R by the variable resistors VR101 and VR102 so that the trigger point moves as shown in FIG.

On the other hand, the voltage detection circuit 4 is a circuit for detecting a change in the power supply voltage, and is composed of capacitors C306 and C305 and resistors R112, R111, and diode D207 in FIG. The sinusoidal alternating current input (V) applied to the point (B) of FIG. 2 is advanced by the capacitor (C306) and then divided by the resistors (R111) and (R112), and both ends of the resistor (R111). Shows the voltage advanced by the capacitor C305. At this time, the voltage V _S detected at the point C is applied to the comparison and trigger circuit 5.

The comparison and trigger circuit 5 is composed of transistors TR1, TR2, resistors R107, R108, R109, R110, diode D206, and capacitor C303 in FIG. And the voltage V _R at the point A and the voltage V _S at the point C are supplied as described above in the trigger circuit 5.

At this time, the comparison and trigger circuit 5 compares the voltage V _S and the voltage V _S to generate a trigger pulse only when V _R > V _S.

This relationship is shown in FIG. 4A and FIG. 4B, where FIG. 4A shows a case where the variable reference voltage V _S is relatively low and FIG. 4B shows a case where the reference voltage V _S is relatively high. . In FIGS. 4A and 4B, the half-wave sine wave represents the detection voltage V _S and the square wave represents the reference voltage V _R , respectively. As is apparent from FIGS. 4A and 4B, the trigger point P _L when the reference voltage V _S is low is slower than the trigger point P _H when the reference voltage V _R is high. In other words, as described above, when the temperature rises and the amount of current flowing into the sensing line 12 becomes large, and thus the reference voltage V _R is changed to decrease, the trigger of the comparison circuit as shown in FIG. Since the point is delayed, the amount of electric power (area of the portion hatched in the fourth portion) that is supplied to the heater is reduced, thereby preventing the temperature from increasing. On the contrary, when the temperature is lowered, the resistance of the heat-sensitive layer is increased, so that the reference voltage (V _R ) is increased, so that the trigger point is fastened, the power consumption (hatched portion of FIG. 4b) is increased, and the temperature is raised, thereby always maintaining a constant voltage. You can do it.

Hereinafter, the process of generating the trigger pulse will be described in detail. When V _R > V _{S, the} path from (a) in FIG. 2 (D204) to (emitter of TR2) to (base of TR2) to (D206) The current flows through the transistor TR2, and the transistor TR2 is turned ON. Also, from the point A, the transistor TR2 is turned on from D204 to the emitter of TR2 to the collector of TR2 to the base of TR1 to the emitter of TR1. The amplified current flows through the path of the transistor) so that the transistor TR1 is also turned on. When transistor TR1 is turned ON, the current charged in capacitor C303 is (C303)->(R107)-> (TR1 collector)-> (emitter of TR1)->(R109)-> (SCR). The SCR is triggered by a rapid discharge in the path of.

The output circuit 6 is a circuit including such an SCR, and finally serves to energize the heater, and serves as a half-wave relay as the SCR. On the other hand, power control and temperature control are not performed when certain parts of the regulator and the electric blanket (or electric yaw) main body are in a bad state, and it is inevitable that there is a function of a safety circuit that can prevent such a state. This becomes indispensable.

That is, when the SCR is short-circuited in the output circuit 6, excessive power is applied to the heater and the temperature is excessively increased. Under normal operating conditions, current flows through the path of the safety fuse (SF) → SCR → heater (11) of FIG. 2, but once the temperature rises, the radius of the diode (D208) → SCR → safety fuse (SF) A large current flows into the furnace, causing the safety fuse (SF) to disconnect momentarily, breaking the circuit. Such a safety circuit is indicated by reference numeral 7 in FIG.

On the other hand, the circuit is overheated when a voltage is applied to the circuit or the circuit becomes uncontrollable due to other reasons, and in such an overheated state, the thermal layer (nylon thermistor) 13 between the heater 11 and the sensing line 12 is overheated. Since the melt | dissolution melt | dissolves and the heater 11 and the sensing line 12 are short-circuited, electric current flows in the path of (heater) → (sensing line) → (R105) → (D201), and the resistance R105 is heated. When the resistor R105 is heated in this manner, the temperature fuse TF sealed together with the resistor R105 is disconnected and the circuit is cut off. Such an arc circuit is indicated by reference numeral 8 in FIG.

When the circuit is extremely shorted, the current fuse SF in the safety circuit 7 is momentarily disconnected to cut off the circuit, thereby preventing an extreme dangerous condition.

In FIG. 2, reference numeral SW denotes the number of power sources of the circuit, and reference numeral 9 denotes a lamp indicating that power is supplied to the circuit.

As described above, according to the present invention, even if any power supply voltage between 90V and 240V is applied, especially in an electric floor plate or an electric yaw, it consumes only a constant power without requiring a separate operation of a user, thereby maintaining a constant temperature. It is possible to achieve the practical effect that the provided thermostat can be provided in a simple structure and inexpensively.

Claims (2)

A heat generating unit 1 consisting of a heater 11, a sensing line 12, and a heat sensitive layer 13, a temperature sensing circuit 2 for sensing a temperature at both ends of the heat generating unit, and a power source voltage selected regardless of a power supply voltage. A reference voltage selection circuit for maintaining a reference voltage (V _R ), which is connected to the temperature sensing circuit (2) in response to a change in the temperature and thus a change in the resistance value of the thermosensitive layer and selected trigger. A voltage varying circuit 3 for varying the reference voltage V _R so that a point can be maintained, and a voltage detecting circuit for detecting a voltage V _S determined according to the power supply voltage by detecting a change in the power supply voltage. (4), the reference voltage V _R from the voltage variable circuit 3 and the detection voltage V _S from the voltage detection circuit 4 are received and compared, and the reference voltage V Trigger pulses only if _R ) is higher than the detected voltage (V _S ) A comparison and trigger circuit (5) for generating a switch, and an output circuit (6) triggered by the trigger pulse to finally energize the heater. 2. A thermostat according to claim 1, wherein safety circuits (7) and (8) are respectively added to block the flow of current in the event of overheating or short circuit of the heat generating section (1).