KR20060081739A - Apparatus for security of heater control device in the radiant type cooker - Google Patents

Abstract

The present invention relates to a heater control safety device for an electric cooker capable of protecting the system circuit against burnout of the relay for the heater control and congestion of the microcomputer.

To this end, the present invention is an electric cooker using an electric heater as a heating source, the microcomputer for outputting the first and second control signals for controlling the driving of the electric heater, connected to a power supply terminal to the first control signal A main relay for switching a power output to the electric heater and a switching according to the second control signal such that power connected to the main relay is supplied to the electric heater to be output by the on operation of the main relay. Provided is a heater control safety device for an electric cooker including a sub relay.

Cooker / Heater / Microcomputer Runaway / Relay Burnout

Description

Apparatus for Security of Heater Control Device in The Radiant type Cooker}

1 is a circuit diagram showing a heater control device of an electric range according to the prior art

2 is a circuit diagram showing a heater control safety device of the electric cooker according to the present invention.

* Explanation of symbols for main parts of the drawings

10: microcomputer 20: malfunction prevention circuit

RY11; Main relay RY21, RY22, RY23: sub relay

C1: capacitor

Q1, Q2, Q3: first, second, third transistor

The present invention relates to a heater safety device for an electric cooker, and more particularly, to a heater control safety device for an electric cooker capable of protecting a system circuit against burnout of a relay for controlling a heater and congestion of a microcomputer.

In general, electrothermal appliances that convert electrical energy to obtain thermal energy are freely controlled, hygienic, and remotely controlled, compared to other types of heat sources. Has been developed as a product.

Among them, an electric range is a cooking apparatus for cooking food using a halogen lamp or an electric heater as a heat source. Such an electric range may be mounted and used on a cook-top of an electric oven or the like.

In this case, an induction heater using an induction heating method and a radiant heater using an electric resistance method may be used as the electric heater.

Among the induction heaters, as power is applied, a high frequency voltage having a predetermined magnitude is applied to the working coil to generate a magnetic field around the working coil.

At this time, the magnetic force line of the induced magnetic field passes through the bottom of the cooking vessel including the iron component placed on the burner top plate, and an eddy current is generated inside the bottom of the cooking vessel, and the cooking vessel is heated by the eddy current to cook. You lose.

On the other hand, the radiant heater is a predetermined power is applied to the heating coil (Heating Coil) to emit high-temperature radiant heat by the self-heating of the heating coil. In other words, cooking is performed while radiated heat is transferred directly to the cooking vessel.

In this way, the electric range using the radiant heater as a heat source is composed of a plurality of burner assemblies, each having a burner assembly in the front space and the rear space in the main body case and controlling the heater of the corresponding burner selected by the user. Cooking will be performed.

Referring to FIG. 1, a conventional control apparatus for a plurality of heaters constituting a burner assembly is as follows.

As shown in the drawing, the heater control apparatus of the prior art comprises a heater (Heater 1, 2, 3) constituting each burner, a microcomputer for controlling the driving of the heater, and 1: 1 for each heater. It is composed of relays (RY1, RY2, RY3) for driving the heater according to the control signal output from the microcomputer.

That is, one relay is configured for each heater and the microcomputer is configured to control on / off of the relay connected to the heater to drive the heater of the burner according to the user's selection.

For example, when driving of the heater 3 is required, the microcomputer outputs a corresponding control signal to switch the relay 3 RY3 corresponding to the heater 3. At this time, when the relay 3 (RY3) is turned on under the control of the microcomputer, the power supply Vcc is started to the heater 3, and the heater 3 is driven.

However, the conventional heater control device controls the power supply of the heater through a relay configured to correspond to each heater, so that when the heater control relay is burned out, continuous power supply is made to the heater due to a relay malfunction.

In other words, if power is continuously supplied to the heater due to the breakage of the relay, a safety accident such as fire may occur.

In addition, the control signal for relay operation is directly output from the microcomputer. If the microcomputer congestion occurs due to the internal error of the microcomputer, the microcomputer not only causes abnormal operation of the relay but also a malfunction of the heater.

The present invention is to solve the above problems, it is an object of the present invention to provide a heater control stabilizer that can prevent the risk situation due to burnout of the heater control relay in advance.

Another object of the present invention is to provide a heater control safety device for preventing malfunction of the relay and the heater due to the microcomputer runaway.

In order to achieve the above object, the present invention is an electric cooker using an electric heater as a heating source, the microcomputer for outputting the first and second control signals for controlling the driving of the electric heater, is connected to a power terminal A main relay switching a power output to the electric heater according to a control signal, and the second control connected to the main relay so that power output by an on operation of the main relay is supplied to the electric heater Provided is a heater control safety device for an electric cooker including a sub relay that switches according to a signal.

In addition, the present invention performs the switching operation of the main relay for the first control signal which is a frequency signal connected to the input terminal of the main relay having a predetermined delay time, the predetermined voltage level due to the micom congestion The continuous first control signal provides a heater control safety device for an electric cooker, further comprising a malfunction prevention circuit unit that does not perform a switching operation of the main relay.

Here, the malfunction prevention circuit unit has one end connected to a capacitor C1 having a first end connected to an output port of a microcomputer to which the first control signal is output, and one end connected to a predetermined constant voltage terminal 5V and connected to one end of the capacitor C1. A resistor R1 having the other end connected thereto, a first transistor Q1 having a base connected to the other end of the capacitor C1, and an emitter connected to the constant voltage terminal 5V, and a base having the first transistor Q1. The second transistor Q2 is connected to the collector and the emitter is connected to the ground terminal, the base is connected to the collector of the second transistor Q2, and the emitter is connected to a predetermined constant voltage terminal 12V. Is composed of a third transistor Q3 connected to an input terminal of the main relay.

In this case, the first and third transistors Q1 and Q3 may be pnp type transistors, and the second transistor Q2 may be npn type transistors.

When the first control signal output from the microcomputer is output as a constant frequency signal having a delay time corresponding to the capacitance of the capacitor C1, the first to third transistors may be charged or discharged by the capacitor C1. It is preferable that Q1) Q2 and Q3 are sequentially turned on to perform the switching operation of the main relay.

Therefore, according to the present invention, by additionally configuring a separate relay for supplying power to the heater, it is possible to prevent a dangerous situation due to damage of the heater control relay.

In addition, according to the present invention, the malfunction of the heater can be prevented by automatically turning off the relay drive during the micom congestion.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described.

Referring to Figure 2, when describing the heater control safety device of the electric cooker according to the present invention.

As shown, the heater control safety device of the present invention, in an electric cooker using an electric heater (not shown) as a heating source, the microcomputer for outputting the first and second control signals for controlling the driving of the electric heater ( 10) is connected to a power terminal (Vcc) is connected to the main relay (RY11), the main relay (RY11) for switching the power output to the electric heater according to the first control signal (main relay RY11) And a sub relay RY21, RY22, and RY23 which switch in accordance with the second control signal so that power output by the on operation of RY11 is supplied to the electric heater.

In addition, the microcomputer 10 performs a switching operation of the main relay RY11 with respect to a first control signal, which is a frequency signal connected to an input terminal of the main relay RY11 and having a predetermined delay time. The control circuit 20 further includes a malfunction prevention circuit unit 20 that does not perform the switching operation of the main relay RY11 with respect to the first control signal at which the constant voltage level is maintained due to congestion.

Here, the malfunction preventing circuit unit 20 is configured between the output port of the microcomputer 10 to which the first control signal is output and the main relay RY11.

In detail, the malfunction prevention circuit unit 20 has one end connected to a capacitor C1 having one end connected to an output port of the microcomputer 10 through which the first control signal is output, and a predetermined constant voltage terminal 5V. A resistor R1 having the other end connected to one end of the capacitor C1, a base connected to the other end of the capacitor C1, and an emitter connected to the constant voltage terminal 5V, that is, one end of the resistor R1. It consists of a 1st transistor Q1.

And a second transistor Q2 having a base connected to the collector of the first transistor Q1 and an emitter connected to the ground terminal, and a base connected to the collector of the second transistor Q2 and the emitter being predetermined. The third transistor Q3 is connected to the constant voltage terminal 12V of and the collector is connected to the input terminal of the main relay.

In this case, the first and third transistors Q1 and Q3 use a pnp type transistor, and the second transistor Q2 uses an npn type transistor.

In addition, one end of the coil part of the main relay RY11 is connected to the collector of the third transistor Q3, and the other end thereof is connected to the ground terminal, and the main relay RY11 is switched by a current generated in the coil part. One end of the device is connected to the power supply terminal Vcc and the other end is connected to a switching device of the sub relays RY21, RY22, and RY23.

The sub relays RY21, RY22, and RY23 may include a coil part having one end connected to the collector of the third transistor Q3 and the other end connected to the output port of the microcomputer 10, in which the second control signal is output. In addition, one end is connected to the switching element of the main relay (RY11) and the other end is composed of a switching element connected to the electric heater.

Such a sub relay is configured to correspond 1: 1 with an electric heater configured in an electric cooker. For example, when three electric heaters are configured (Heater 1, 2, 3) as shown, for each electric heater The second control signal output port of the microcomputer 10 and the sub relays RY21 (RY22) and RY23 are respectively required.

Referring to the operation of the heater control safety device according to the present invention configured as described above in detail.

First, when the cooking operation is required, the microcomputer 10 for controlling the entire system simultaneously outputs the first control signal and the second control signal to control the operation of the electric heater.

At this time, when the first control signal output from the microcomputer 10 is output as a constant frequency signal having a delay time corresponding to the capacitance of the capacitor C1 of the malfunction preventing circuit unit 20, The charging / discharging is normally performed, which causes the first transistor Q1 to be turned on.

As the first transistor Q1 is turned on, the second and third transistors Q2 and Q3 are sequentially turned on, whereby a current is conducted to the coil portion of the main relay RY11 and a switching element is turned on.

Here, when the main relay RY11 is turned on, the power supply Vcc for driving the electric heater is supplied.

At this time, when the sub relays RY21, RY22, and RY23 are turned on according to the second control signal output from the microcomputer 10, the power Vcc supplied by the on operation of the main relay RY11 is supplied to the corresponding electric relay. Supply to the heater.

Therefore, the present invention can supply power to the electric heater only when the control is performed by the main relay RY11 as well as the sub relays RY21, RY22, and RY23 provided corresponding to the electric heater. That is, the sub relays RY21, RY22, and RY23 may be controlled while the main relay RY11 is turned on.

On the other hand, when the first control signal output from the microcomputer 10 is output as a signal that the high level (5V) or low level (0V) is sustained due to the microcomputer congestion, the capacitor (C1) of the malfunction prevention circuit unit 20 Since the charging / discharging is not performed normally, the first transistor Q1 is maintained in the off state.

That is, when the microcomputer 10 congestion occurs, the malfunction prevention circuit unit 20 does not operate, so that the main relay RY11 is automatically turned off to prevent the malfunction of the main relay RY11.

Therefore, according to the present invention, the main relay RY11 and the malfunction prevention circuit unit 20 are additionally configured to cause a heater that may be caused by breakage of the sub relays RY21, RY22, and RY23, which are heater control relays, or by the runaway of the microcomputer 10. To prevent malfunction.

The present invention is not limited to the above-described embodiments, and can be modified by those skilled in the art as can be seen from the appended claims, and such modifications are within the scope of the present invention.

Referring to the effect of the heater control safety device of the electric cooker according to the present invention described above are as follows.

First, by additionally configuring a separate relay to control the power supply of the heater, it is possible to prevent safety accidents such as fire as well as malfunction of the heater due to damage to the heater control relay.

Second, by preventing the malfunction of the relay and heater due to the microcomputer congestion, it is possible to improve the product reliability by protecting the system circuit.

Claims (5)

In an electric cooker using an electric heater as a heating source, A microcomputer for outputting first and second control signals for controlling driving of the electric heater; A main relay connected to a power terminal for switching a power output to the electric heater according to the first control signal; And a sub relay connected to the main relay and switching according to the second control signal so that power output by an on operation of the main relay is supplied to the electric heater. Heater control safety device. The method of claim 1, A first control signal, which is a frequency signal connected to an input terminal of the main relay and having a predetermined delay time, performs a switching operation of the main relay, and the first voltage maintains a predetermined voltage level due to the micom congestion. The control signal heater control safety device of the electric cooker, characterized in that it further comprises a malfunction prevention circuit unit that does not perform the switching operation of the main relay. The method of claim 2, The malfunction prevention circuit portion A capacitor C1 having one end connected to an output port of the microcomputer to which the first control signal is output; A resistor R1 having one end connected to a predetermined constant voltage terminal 5V and the other end connected to one end of the capacitor C1; A first transistor Q1 having a base connected to the other end of the capacitor C1 and an emitter connected to the constant voltage terminal 5V; A second transistor Q2 having a base connected to the collector of the first transistor Q1 and an emitter connected to the ground terminal; The base is connected to the collector of the second transistor (Q2), the emitter is composed of a third transistor (Q3) is connected to a predetermined constant voltage terminal 12V, the collector is connected to the input terminal of the main relay Heater control safety of the electric cooker. The method of claim 3, wherein And the first and third transistors (Q1) (Q3) are pnp type transistors, and the second transistor (Q2) is an npn type transistor. The method of claim 3, wherein When the first control signal output from the microcomputer is output as a constant frequency signal having a delay time corresponding to the capacitance of the capacitor C1, the first to third transistors Q1 may be charged or discharged by the capacitor C1. (Q2) (Q3) is sequentially turned on (Turn On) heater control safety device for an electric cooker, characterized in that the switching operation of the main relay is performed.

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