KR19990061436A - Micro-Crystal Drive Circuit of Microwave Oven - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro-clit rod driving circuit of a microwave oven, comprising four diodes D3, D4, D5, and D6 connected in a bridge form to which commercial power is input, and the bridge diodes D3, D4, D5, A bridge double voltage rectifier circuit composed of two series connected capacitors C3 and C4 connected in parallel with the output terminal of D6) or a capacitor C5 connected to the positive output side of a commercial power supply, and a parallel connection with the capacitor C5. And a cockcroft back pressure rectifying circuit comprising a diode D7, a diode D8 connected in parallel with the diode D7, and a capacitor C6 connected in parallel with the diode D8.

Therefore, in the present invention, in the driving circuit of the micro-crust rod, it is possible to reduce the breakdown voltage of the diode constituting the circuit and to simplify the insulation structure, thereby reducing the cost.

Description

Micro-Crystal Drive Circuit of Microwave Oven

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a micro-clystride drive circuit used as a microwave oscillation tube in a microwave oven, and more particularly, to a micro-klystrode that can drive a micro-klystrode with a simpler structure and a stable voltage. It relates to a clad rod driving circuit.

As is known, conventional microwave ovens have been used by employing a magnetron driven at a high voltage of 4KV as an ultra-high frequency oscillation tube. Such a magnetron is a kind of two-pole vacuum tube that generates microwaves, that is, ultra-high frequencies, and as shown in FIG. 1, when power is applied to an input unit composed of a condenser 11, a choke coil 12, and the like, the filament 1 of the cathode portion The hot electrons emitted by the are discharged into the working space 4 between the ends of the plurality of vanes 3 and the filament 1 extending on the inner wall of the cylindrical anode 2 to form an electric field in the working space 4. In addition, a magnetic field is applied to the working space 4 by a magnetic circuit composed of a magnet 5 and a magnetic pole 6 so that hot electrons undergo a cycloid movement, and the energy of the movement is taken into the vane 3 and the strap 8. By heating the foodstuffs by radiating the microwaves to the cooking chamber (not shown) through an antenna 7 connected to the vane 3 and an output unit composed of the A ceramic 9 and the A seal 10, etc. And cooked.

However, such a conventional microwave oven using a magnetron requires a high voltage transformer and a high pressure diode according to the high pressure driving, so there is a safety problem, and a magnet employing a resonance method by electromagnetic movement in an electromagnetic field is required. This was a heavy and expensive manufacturing problem.

Therefore, in order to solve this problem, a microwave oven using Klystron as an ultra-high frequency oscillation tube has been developed. As shown in FIG. 2, the chrystron 40 has an input terminal 42 for receiving a power source, and a Klystron body that generates microwaves, that is, ultra-high frequencies in response to the supply of power to the input terminal 42. 41, an antenna 32 for transmitting microwaves from the Klystron body 41, a cooling unit 43 for dissipating heat generated in the Klystron body 41 to the outside, and to receive electrons. It consists of an installed electron beam concentrator 49, the cooling unit 43 supports the cooling fin 44 and the cooling fin 44 arranged to disperse heat generated by the reception of electrons, and the electron beam collector A cooling rod 46 arranged to transfer heat from the shorthand 49 to the cooling fins 44, and a closure 48 surrounding the cooling fins 44, and further comprising an input terminal 42 An electron gun 50, an electron gun 50, and an electron beam that receive power through the power source and generate electrons by the received power source. A pair of magnets 52 provided around the shorthand 49, a yoke 54 acting as a guide constituting a closed loop by the magnets 52, and a plurality of cavities are sandwiched between the mark 52. Tube 56.

However, the microwave oven employing Klystron is still driven by a high voltage power supply, so the input terminal must be insulated from the Klystron body with a separate insulating member, and a high voltage transformer is needed to boost the commercial power to high voltage, thus making the product heavy. In addition, since the motion of the electrons is complicated, excessive noise is generated, the cooling structure is complicated, and the structure has a plurality of cavities. A magnet is required for focusing the electron beam, and a filter is required, so the structure is complicated. There was a downside.

Therefore, in order to overcome these disadvantages, a microwave oven using a micro-klystrode, which is operated at a low voltage and has a simple structure, eliminates the risk of high voltage and achieves a light weight, has been developed.

3 is a cross-sectional view showing the structure of the micro-clist as described above.

As shown in FIG. 3, the micro-clist rod 100 includes a power input unit 110 that receives a low voltage, a heater 120 that generates power by receiving power from the power input unit 110, and the heater ( Input cavity including a ring-shaped cathode 132 sequentially installed at a predetermined interval on the upper portion of the 120, and a blocking capacitor 136 having a choke structure provided on the side of the first grid 134 and the cathode 132 130, the cathode 132 is heated to a predetermined operating temperature by the heat of the heater 120 to emit hot electrons, and the first grid 134 is applied with a bias voltage to the cathode 132. Electrons emitted from the capacitor, and the blocking capacitor 136 energizes the surface current due to the formation of microwaves in the input cavity 130, and the cathode 132 and the first grid 134 are insulated from each other. To radiate heat An anode 146 in which several cooling fins 148 are arranged radially and an electron passing through the first grid 134 of the input cavity 130 pass through the second grid 142 to induce surface current. And the output cavity 140 in which the electrons accumulated in the input cavity 130 are density-modulated, and the microwaves are formed by the surface current induced by accelerating the modulated electrons, and the microwaves formed in the output cavity 140. And a feedback means 160 provided between the radiating antenna 150 and the input / output cavities 130 and 140 to feed back a portion of the microwaves formed in the output cavity 140 to the input cavity 130. do.

On the other hand, as described above, since the micro-clit rod can be driven at a relatively low voltage of 500 to 700 Vdc, it is possible to simply use a back-pressure rectifier for commercial power without using a transformer. Used as a circuit to drive the furnace.

Fig. 4 is a circuit diagram showing a conventional micro-clist drive circuit for driving a micro-crust rod.

As shown in FIG. 4, the conventional micro-clithide driving circuit is formed by combining diodes D1 and D2 and capacitors C1 and C2 in the form of a bridge.

The commercial power input is rectified at the diodes D1 and D2 during the positive and negative half-wave cycles, and then charged to the capacitors C1 and C2. Back voltage is obtained by connecting the two capacitors C1 and C2 in series. Diode D1 and capacitor C1 rectify and charge during a standing wave cycle, while diode D2 and capacitor C2 rectify and charge during a short wave cycle. At this time, the breakdown voltages of the diodes D1 and D2 are 2√2 times the input voltage, and the breakdown voltages of the capacitors C1 and C2 are √2 times the input voltage.

As shown in FIG. 3 of the micro-clist rod configured as described above, the output is connected to the anode 146 of the micro-crust rod, and the negative side is connected to the cathode 132. Drive power to the micro-clides.

In addition, when the micro-clit with the driving circuit configured as described above grounds one output terminal of the driving circuit, the capacitor C1 and the capacitor C2 are shorted because of the ground at the commercial power supply input terminal. When mounted in a microwave oven, the anode of the micro-clist must be insulated mechanically from the main chassis of the microwave oven.

Therefore, the conventional micro-clithlide driving circuit as described above has a problem that the breakdown voltage of the diode constituting the circuit is large and the insulation structure is complicated and expensive.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems described above, and an object of the present invention is to reduce the breakdown voltage of the diode constituting the circuit and to simplify the insulation structure in constructing a driving circuit for driving the micro-clit. It is to provide a micro-crust rod driving circuit of a microwave oven.

According to a preferred embodiment of the present invention for achieving this object, a heater that generates heat by a predetermined AC power source, a cathode that is heated to a predetermined operating temperature by the heat of the heater to emit hot electrons, and from the cathode A first grid for accumulating emitted electrons, a second grid for generating microwaves by inducing surface currents as electrons passing through the first grid pass, and an anode for outputting microwaves generated in the second grid; In the micro-clide drive circuit for rectifying the input commercial power, and boosting the voltage to a low voltage of a predetermined level in order to drive the micro-crust rod to provide to the cathode and the anode, the circuit is a commercial Four diodes (D3, D4, D5, D6) connected in the form of a bridge to which power is input, and the It is characterized in that the bridge double voltage rectifier circuit consisting of two capacitors (C3, C4) in series connected in parallel with the output terminal of the ridge diode (D3, D4, D5, D6).

According to another preferred embodiment of the present invention for achieving this object, a heater that generates heat by a predetermined AC power source, a cathode that is heated to a predetermined operating temperature by the heat of the heater to emit hot electrons, and from the cathode A first grid for accumulating emitted electrons, a second grid for generating microwaves by inducing surface currents as electrons passing through the first grid pass, and an anode for outputting microwaves generated in the second grid; In the micro-clide drive circuit for rectifying the input commercial power, and boosting the voltage to a low voltage of a predetermined level in order to drive the micro-crust rod to provide to the cathode and the anode, the circuit is a commercial The capacitor C5 is connected in parallel with the positive output side of the power supply, and is connected in parallel with the capacitor C5. It characterized in that odd (D7), and the cock loft back pressure rectifier circuit consisting of the diode (D7) and a diode connected in parallel (D8) and a diode (D8) connected in parallel with the capacitor (C6).

1 is a schematic cross-sectional view showing the structure of the mark netron used as an ultra-high frequency oscillation tube for a microwave oven,

2 is a schematic cross-sectional view showing the structure of Klystron used as a microwave microwave tube for microwave oven,

Figure 3 is a cross-sectional view showing the structure of the micro-clides used as a microwave microwave oscillation tube,

4 is a view showing a conventional micro-crust rod driving circuit,

5 is a view showing a microclid rod driving circuit according to an embodiment of the present invention;

FIG. 6 is a diagram illustrating a microclidean driving circuit according to another exemplary embodiment of the present invention. FIG.

<Description of the code | symbol about the principal part of drawing>

100: micro climb rod 102: bracket

104: filter box 110: power input unit

120, 125: Heater 130: input cavity

132: cathode 134: first grid

136: blocking capacitor 140: output cavity

142: second grid 144: projection

146: anode 148: cooling fin

150 antenna 152 coupling end

154: antenna ceramic 156: antenna cap

160: feedback rod 170: slot-shaped rectangular opening

172: ceramic pin C: capacitor

D: Diode

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

FIG. 5 is a circuit diagram illustrating a micro-clith drive circuit according to an exemplary embodiment of the present invention.

As shown in FIG. 5, the micro-clystride driving circuit according to the present invention includes four diodes D3, D4, D5, and D6 connected in a bridge form, and output terminals of the bridge diodes D3, D4, D5, and D6. It consists of two series-connected capacitors C3 and C4 connected in parallel with each other, which is commonly referred to as a bridge double voltage rectifier circuit.

The input power source is full-wave rectified by the bridge diodes D3, D4, D5, and D6, and the potential difference across the capacitors C3 and C4 connected in series becomes an output voltage.

In addition, according to the present invention, when using a conventional diode, the breakdown voltage should be 2√2 times the input voltage rms, whereas the bridge diodes D3, D4, D5, and D6 are √2 times the input voltage. Only internal pressure of

In addition, the breakdown voltage of the capacitors C3 and C4 should be equal to or greater than the maximum value of the input voltage. When measuring the voltage charged to the capacitors C1 and C2 after the full-wave rectification by applying a commercial power of about 220V, a DC voltage of about 620V is measured, so that the stability of the voltage is used in order to use a DC voltage of about 500V to 700V. Since is related to the output efficiency, the capacitor (C1, C2) is about 820 kHz or more so that the ripple amount does not exceed 3.27%.

FIG. 6 is a circuit diagram illustrating a micro-clit rod driving circuit according to another exemplary embodiment of the present invention.

As shown in FIG. 6, the micro-clithrod drive circuit according to the present invention includes a capacitor C5 connected to a positive output side of a commercial power supply, a diode D7 connected in parallel with the capacitor C5, and a diode. A diode D8 connected in parallel with (D7) and a capacitor (C6) connected in parallel with the diode (D8), and the (-) side of the commercial power supply is grounded. It is called the slave voltage multiplier.

As described above, the micro-clystride drive circuit composed of the cockcroft back pressure rectifier circuit operates by dividing the operation cycle into a charge cycle and a pump up cycle.

In addition, the breakdown voltages D7 and D8 of the diode have a value of 2√2 times the input voltage rms, the breakdown voltage of the capacitor C5 is √2 times the input voltage, and the breakdown voltage of the capacitor C6 is the input voltage. It has an internal pressure of 2√2 times of, and the capacity of the capacitor C5 is about 1500 kW, and the capacitor C6 is about 820 kW.

And, as shown in Figure 6, the micro-clithrod drive circuit using the cockcroft back pressure rectifier circuit has a relatively insulated structure, that is, a ground structure is simple.

As described above, the present invention uses a bridge double voltage rectifier circuit or a cockcroft back voltage rectifier circuit to reduce the breakdown voltage of the diode constituting the circuit and makes the insulation structure relatively simple. As it can, the cost can be reduced.

Claims (2)

A heater that generates heat by a predetermined AC power source, a cathode that is heated to a predetermined operating temperature by heat generation of the heater to emit hot electrons, a first grid that accumulates electrons emitted from the cathode, and the first grid In order to drive a micro-clyst including a second grid for generating microwaves by inducing surface currents as the electrons passing through them and an anode for outputting the microwaves generated in the second grid, the commercial power input is rectified. And boosting the voltage to a low voltage of a predetermined level to provide the cathode and the anode to the cathode. The circuit includes four diodes D3, D4, D5, and D6 connected in a bridge form to which commercial power is input, and two series connected in parallel with the output terminals of the bridge diodes D3, D4, D5, and D6. A micro-clit rod drive circuit of a microwave oven, characterized in that it is a bridge double voltage rectifier circuit composed of capacitors (C3, C4). A heater that generates heat by a predetermined AC power source, a cathode that is heated to a predetermined operating temperature by heat generation of the heater to emit hot electrons, a first grid that accumulates electrons emitted from the cathode, and the first grid In order to drive a micro-clyst including a second grid for generating microwaves by inducing surface currents as the electrons passing through them and an anode for outputting the microwaves generated in the second grid, the commercial power input is rectified. And boosting the voltage to a low voltage of a predetermined level to provide the cathode and the anode to the cathode. The circuit includes a capacitor C5 connected to a positive output side of a commercial power supply, a diode D7 connected in parallel with the capacitor C5, a diode D8 connected in parallel with the diode D7, and the diode A micro-clit rod drive circuit of a microwave oven, characterized in that it is a cockcroft back pressure rectifier circuit composed of a condenser (C6) connected in parallel with (D8).