KR19980031218A - Microwave combined high voltage drive device - Google Patents

Abstract

The present invention relates to a high-voltage control panel of a microwave oven capable of using a power source frequency used in a microwave oven (Micro Wave Oven) as 50/60 Hz. By eliminating the High-Voltage Condenser and the High Voltage Relay, you can set the tap to compensate for the lowered output compared to 60Hz when the 50Hz power is selected, and the same condenser. It is possible to drive high voltage driving device with only and relay, and by installing a relay terminal that detects power frequency from Micom and selects 60Hz power or 50Hz power. As a device to obtain a high frequency, the high frequency capacitor and the high voltage condenser according to the use of the combined frequency can be used. Reducing the cost and wiring process according to the deleted relay (High Voltage Relay) will allow you to reduce the assembling steps.

Description

Microwave combined high voltage drive device

The present invention relates to a microwave oven, and more particularly, to a high-pressure driving apparatus of a microwave oven, which can be used as a power source frequency used in the microwave as 50/60 Hz.

In general, a microwave oven may be broadly divided into an oscillation unit, a high pressure unit, a control unit, and a heating chamber.

The oscillator consists of a magnetron that generates high frequency, a waveguide that leads the high frequency to the heating chamber, and a cooling fan that cools the magnetron. The control part is a time switch or a control circuit for controlling the heating time. Finally, the heating chamber is composed of a heating chamber, a turntable and a door for taking in and out food, which are closed at high frequency.

Therefore, the microwave oven generates high-frequency electromagnetic waves by applying high voltage electricity to an ultra-high frequency oscillator tube called magnetron, and heats food by using frictional heat caused by billions of rotational motions generated when the electromagnetic waves hit and absorb the food. to be.

As shown in FIG. 1, a conventional 60 Hz frequency-only microwave high voltage driving device includes a power relay 20, a high voltage capacitor 40, a high voltage diode 50, a magnetron 60, and a high voltage transformer 70. Consists of Such microwave ovens are designed not to be used at different power frequencies, eg 50 Hz and 60 Hz.

If a frequency of 50 Hz is input to the high voltage driving device, additional use of a high voltage relay and a high voltage capacitor is necessary to compensate the output drop at 50 Hz as a voltage to the high voltage transformer 70 based on 60 Hz.

Such a conventional high pressure drive device not only increases the cost burden due to the additional use of an expensive high voltage relay and a high pressure capacitor, but also increases the number of assembly operations due to the addition of wiring.

Accordingly, the present invention has been made to solve the above problems, to provide a high-voltage driving device of a 50 / 60Hz combined frequency microwave oven to operate the high-voltage driving device using the same capacitor and relay used in a 60-Hz dedicated microwave oven. Has its purpose.

In order to achieve the above object, the present invention, in the microwave 50 / 60Hz high-frequency driving device, a magnetron for generating a high frequency, providing a high voltage to the magnetron, a transformer having one intermediate tap in the primary coil and 50/60 Hz of a microwave oven comprising a relay switch for selectively switching between a primary coil and an intermediate tap of a transformer, and a control means for sensing a frequency of an input power source and providing a switching control signal to the relay switch. Provides a dual frequency high pressure drive device.

1 is a detailed view showing a high-pressure driving device of a microwave oven using a conventional 60 Hz dedicated frequency.

Figure 2 is a detailed view showing a high-pressure driving device of a 50 / 60Hz combined frequency microwave oven as a preferred embodiment of the present invention.

3 is a flowchart showing a state step according to a frequency change as an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: microcomputer 20: power relay

30: relay optional 40: high voltage condenser

50: high voltage diode 60: magnetron

70: high pressure transformer

The above and other objects and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings by those skilled in the art.

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

Referring to Figure 2, a circuit diagram of a high-voltage drive device of a 50 / 60Hz combined frequency microwave oven according to the present invention is shown. The high-voltage driving device of the present invention detects the frequency of the AC power input to the microcomputer 10 to provide a relay switching signal (switching), and the power relay 20 for switching the high-voltage driving circuit regardless of the frequency magnitude And a selection relay 30 for selectively switching according to the frequency magnitude sensed by the microcomputer 10, a high voltage capacitor 40 for obtaining a capacitance (capacitance to accumulate charge), and a current in a forward direction. It includes a high voltage diode (50) for flowing a, a magnetron (60) for outputting energy in the rotational motion of electrons, and a transformer (70) for amplifying the input power to provide a high voltage to the magnetron (60).

The transformer 70 is composed of taps T1, T2, and T3 mounted on the coil and using a rate of change of voltage according to the number of turns of the coil (the number of turns of the coil). The taps T3 and T2 are respectively connected to the contacts a and b of the relay 30 for supplying the input power, and the tap T1 is connected to the other end of the input power.

The operating principle of the high-pressure driving device of the 50 / 60Hz combined frequency microwave oven according to the present invention will be described in detail with reference to FIG. 3.

First, when AC power is input to the microcomputer 10, the microcomputer 10 switches the power relay 20 to provide the input power to the magnetron 60, and adjusts the magnitude of the frequency of the input AC power. Detect (step 100). If it is determined that the sensed signal is a 60Hz frequency, the microcomputer 10 sends a first relay control signal to the selection relay 30. In response to the relay control signal from the microcomputer 10, the selection relay 30 switches to the relay contact a corresponding to the frequency magnitude at 60 Hz (step 200). When the relay contact is made, a high voltage is formed from the high voltage transformer 70 and accumulated in the high voltage condenser 40. The magnetron 60 outputs energy due to the vibration of the coil with the applied voltage. Through this process, constant power can be obtained at 60 Hz.

Similarly, when AC power is input to the microcomputer 10, the microcomputer 10 switches the power relay 20 to provide the input power to the magnetron 60, and adjusts the magnitude of the frequency of the input AC power. Detect (step 100). If it is determined that the sensed signal is a 50Hz frequency, the microcomputer 10 sends a second relay control signal to the selection relay 30. In response to the relay control signal from the microcomputer 10, the selection relay 30 switches to a relay contact b corresponding to a frequency magnitude of 50 Hz (step 300). When the relay contact is made, a high voltage is formed from the high voltage transformer 70 and accumulated in the high voltage condenser 40. The magnetron 60 outputs energy due to the vibration of the coil with the applied voltage. Through this process, a constant power can be obtained at 50 Hz.

On the other hand, since the 50Hz power frequency is used for the high-voltage drive device based on 60Hz, the high-voltage transformer of the high-voltage drive device for the 50Hz power supply to compensate for the output degradation due to the removal of the high-voltage relay and the high-voltage capacitor described in FIG. The intermediate tap T2 is set in the coil of the geoformer 70. The relationship between the number of turns of the coil and the voltage magnitude according to the tap T2 setting is described as follows.

If the number of windings of the left coil (primary coil) of the high voltage transformer 70 is N1 and the voltage is V1, and the number of windings of the right coil (secondary coil) is N2 and the voltage is V2, A relationship in which the turn ratio α = N1 / N2 = V1 / V2 indicating the number of turns of the coil is established. If N1 and N2 are set to 30 and V1 is set to 10 (V), a voltage of 10 (V) flows through V2. However, when N1 is 20 and N2 is 30 and V1 is 10 (V), the voltage flowing through V2 is 15 (V). Therefore, it can be seen that when the intermediate tap T2 is set to reduce the number of coils of the high voltage transformer 70 for the 50 Hz power supply, the voltage flowing to V2 increases.

In this way, when the 50 Hz power frequency is input to the high-voltage driving device based on 60 Hz, the intermediate tap T2 is set to compensate for the output drop as the voltage, and then, at 50/60 Hz according to the frequency selection of the selection relay 30. Constant power and static characteristics can be obtained.

As described above, the present invention uses the same condenser and relay as used in a 60-degree microwave oven, and the high-voltage drive device is used in a high-voltage drive device of a microwave oven, which uses a power source frequency that can be driven at 50/60 Hz. Regarding this, it is possible to obtain the constant output and the static characteristics with only the same capacitor and the relay, thereby reducing the cost and wiring process of eliminating the high voltage capacitor and the high voltage relay, thereby reducing the assembly labor.

Claims (2)

In the microwave and 50 / 60Hz frequency combined high pressure drive device, Magnetron generating high frequency; A transformer providing a high voltage to the magnetron and having one intermediate tap in the primary coil; A relay switch for selectively switching between a primary coil and an intermediate tap of the transformer; 50 / 60Hz combined frequency high voltage drive of the microwave oven, characterized in that the control means for sensing the frequency of the input power to provide a switching control signal to the relay switch. According to claim 1, wherein the relay switch 50/60 Hz frequency combined high voltage drive of the microwave oven, characterized in that the switching to the intermediate tap when the frequency sensed by the control means is 50 Hz.