KR960001623A - Control circuit of high frequency heating device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency heating apparatus, and more particularly, to a control circuit which attempts to prevent damage to an inverter even in the case of external power supply noise (instantaneous blackout).

In the control circuit of the conventional high frequency heating device, since the falling edge signal does not appear on the secondary side of the transformer when the first device is driven, the synchronous detection unit cannot detect the synchronous signal. There is a problem such that the on, off switching device is broken because it is not detected when the short circuit.

According to the present invention, the control circuit of the high frequency heating apparatus is configured to apply the initial driving signal of the high frequency heating apparatus internally, and also to perform the forced switching only a few times during a momentary power failure, so that the switching element remains off during the power failure time, When recovering, it outputs the same signal as the initial drive signal to protect the switching element during a momentary power failure.

Description

Control circuit of high frequency heating device

As this is a public information case, the full text was not included.

1 is a control circuit diagram of a conventional high frequency heating apparatus,

(A) of FIG. 2 is a waveform diagram showing the waveform output from the left side of the transformer 2 of FIG. 1, (B) is a clock diagram showing the clock output from the falling edge detector of the synchronous signal detector of FIG. A clock diagram showing the clock of the signal, (d) is a clock diagram showing the clock output from the flip-flop of FIG. 1, (e) a clock diagram showing the clock output from the reference clock output unit of FIG. 1, (bar) Switching state of the switching element according to the clock output from each block,

4 is a control circuit diagram of the high frequency heating apparatus of the present invention.

Claims (2)

Bridge diode BD11 for rectifying the power voltage output from the power supply unit 1, choke coil L11 and condenser C11 for smoothing the voltage rectified in the bridge diode BD11, and the choke coil L11. And a relay RY1 for selectively outputting the voltage smoothed at the condenser C11 between the transformer T1 and the working coil 2, and a power supply voltage rectified by the bridge diode BD1. The transistor Q11 for switching on / off switching of the transformer T1 or the working coil 2 selected by the step and the rectified power supply voltage applied by the relay RY1 is stepped up to induce high voltage on the secondary side. The transcoil T1, the working coil 2 for heating the rectified power supply voltage applied by the relay RY1 to heat food contained in the container, and the high voltage induced by the trans T1 by half-wave voltage. Cone output to the magnetron (3) A high frequency wave composed of a denser C13 and a diode D12, and a magnetron 3 that generates a high frequency wave by receiving a power supply voltage half-doubled from the capacitor C13 and the diode D12 to generate a high frequency wave to heat food in the cavity. In a high-frequency microwave oven combined with an induction heating cooker, a current detector 4 for detecting a current input to the bridge diode BD11, an output setting unit 5 for outputting an output level set by a user, and the current A comparator 6 comparing the level of the signal detected by the detector 4 with the level output from the output setting unit 5, and a power supply voltage resonance resonating the power supply voltage supplied from the power supply 1 to output a clock. An up-down counter 8 that receives a clock from the power supply resonator 7 and adjusts a register value by up and down by a value set by a level value compared by the comparator 6; , Down counter ( 8) a set memory unit 8a for storing the set value of 8), a down counter 9 for lowering the register value by the value set in the up-down counter 8, and a reference clock to generate a reference clock. A reference clock output unit 10 outputting to the counter 9, an initial driver 11 outputting an initial driving signal, and the flip-flop 12 are controlled to turn on and off the transistor Q11. The driving unit 13, the falling edge detection unit 14 for detecting the falling edge signal of the signal output from the primary side of the urging coil or the boosting transformer, and the momentary power failure protection unit 15 for protecting the circuit in the case of a power failure. Control circuit of high frequency heating device composed of The clock generator of claim 1, wherein the reference clock generator 10 comprises a crystal X1 oscillating to generate a clock, and capacitors C14 and C15 smoothing a clock generated from the crystal X1. The initial driver 11 loads the register value counted by the down counter 9 and receives a counter output from the reference clock generator 10 to count the counter 11a and the set value of the counter 11a. And a set value key storage unit 11b for storing, and the instantaneous power failure circuit unit 15 loads a signal output from the power supply voltage notice unit 7 and receives a clock output from the falling edge detection unit 14 to down count. A down count 15a, a set memory 15b for storing the set value of the down count 15a, a signal output from the power supply voltage resonator 7, and a signal counted from the down count 15a. Consists of a flip-flop 15c that flips The control circuit of the high frequency heating device, characterized in that. ※ Note: The disclosure is based on the initial application.