CN2522764Y

CN2522764Y - Three-phase electromagnetic range using pulse power output transformer

Info

Publication number: CN2522764Y
Application number: CN 01268448
Authority: CN
Inventors: 沈亦飞; 宋立昆
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-11-14
Filing date: 2001-11-14
Publication date: 2002-11-27
Anticipated expiration: 2011-11-14

Abstract

The utility model discloses a three-phase electromagnetic oven by using of a impulse power output transformer; the utility model comprises a power output circuit; the power output circuit is a series-connecting normal syntony circuit; a peak value of a power tube collecting electrode is only an input electrical supply pressure; the situation that the voltage attacks the power tube does not happen; an assistant wiring is used for detecting whether a boiler is on or not on an oven surface so as to avoid the relationship between the detection of boiler and the frequency tracking; the detection for the boiler on or not is more accurate. The electromagnetic oven is suitable to be used for cooking in a train restaurant, hotel, restaurant and army and so on.

Description

Three-phase electromagnetic kitchen range with the pulse power output transformer

Technical field

The utility model relates to electromagnetic stove, specifically is the three-phase electromagnetic kitchen range that utilizes the pulse power output transformer.

Background technology

Up to the present, existing electromagnetic stove technology, the operation principle of its power output grade circuit are as shown in Figure 1: power transistor BG opens once under driving pulse, and electric current is got back to power cathode through heater coil L, power tube BG; After BG ended, electric current can not suddenly change among the L, and through resonant capacitance C2, high-frequency bypass capacitor C1 forms the loop; When electric current among the L reduced to zero, voltage was charged to the highest among the C2; This moment, C2 began discharge by L, C1, and when C2 voltage reduced to zero, electric current can not suddenly change among the L, and electric current is by C1 among the L at this moment, and sustained diode forms the loop; This mode of operation has two big drawbacks: the crest voltage that (1) power transistor bears is 3-4 a times of power supply amplitude Ec, and sharply raise along with the increasing of power output, the withstand voltage allowance of power tube is not almost had, if resonant capacitance C2 open circuit, electric current discharge off loop among the heater coil L produces current break, induce high high voltage, moment the breakdown power pipe.In case so input voltage has than great fluctuation process, or the C2 capacity diminishes, opens a way, immediately the breakdown power pipe.(2) maximum that terminates in electric current of power transistor, so pipe loss is very big, and the power tube heating is severe.

Summary of the invention

The purpose of this utility model is: solve the power tube heating severity that present electromagnetic stove exists, the problem that pipe easily punctures.A kind of three-phase electromagnetic kitchen range with the pulse power output transformer is provided.

The power output grade circuit of three-phase electromagnetic kitchen range of the present utility model, it is characterized in that, mate full bridge power pipe T1, T2, T3, T4 and heater coil L with pulse power output transformer B, wherein the elementary two ends of pulse power output transformer B are connected with the emitter stage of power tube T1, T3 respectively, the secondary two ends of pulse power output transformer B are connected with heater coil L, resonant capacitance C under the series connection respectively, the colelctor electrode of T1, T3 extremely links to each other with "+" of dc source, and the emitter stage of T2, T4 extremely links to each other with "-" of dc source.

Operation principle of the present utility model is: the 380V three phase mains is through the rectification of 50A three-phase bridge, behind the radio circuit capacitor filtering, output 530V DC voltage is given power tube, power tube is reverse into DC voltage the square voltage pulse of 25KHZ under driving pulse drives, export by the full-bridge circuit that T1, T2, T3, T4 form, behind pulse power transformer B transforming impedance, output low-voltage, high-current high-frequency impulse is given heater coil, makes the iron pan induction produce eddy-current heating.

Because the utility model has adopted the quasi-resonance circuit, the power tube collector peak voltage only is the input supply voltage amplitude, and irrelevant with the power output size, and the phenomenon of voltage breakdown power tube has not existed, even the resonant capacitance open circuit is also harmless.T1, T4; T3, T2 all open at the voltage zero-cross place and end, and therefore the pipe consumption is minimum.

Adopting the pulse power output transformer to come the impedance of conversion heater coil among the present invention is beyond example in electromagnetic stove, has solved the making of coil with electromagnetic stove power is big, the contradiction of coil dimension between greatly.And can recently obtain specified power, coil dimension and operating frequency by the flexible combination of change L, C and the transformation of B.

The present invention makes the power of electromagnetic stove no longer be subjected to the restriction of the withstand voltage allowance of power tube, and the designer can design the power of electromagnetic stove as required.The power of the utility model electromagnetic stove can be accomplished 8KW, and adjustable continuously from 1.5KW to 8KW, is fit to dining car, and hotel, restaurant, army's cooking are used, the gas range that has surpassed restaurant's use soon of its speed.Under the 8KW power output, because of the pipe consumption is little, can be during debugging without cooling device by the power output stage few minutes of operation.Add overcurrent, kinds of protect such as overheated, the dependability of power tube is guaranteed.

The electromagnetic stove power output grade circuit schematic diagram that description of drawings Fig. 1 is old.Fig. 2 electromagnetic stove power output grade circuit of the present utility model schematic diagram.

Specific embodiment embodiment 1: made a three-phase electromagnetic kitchen range that utilizes the pulse power output transformer, its power output grade circuit schematic diagram as shown in Figure 2, T1, T2, T3, T4 form full-bridge circuit, the elementary two ends of pulse power output transformer B are connected with the emitter stage of power tube T1, T3 respectively, the secondary two ends of pulse power output transformer B are connected with heater coil L, resonant capacitance C under the series connection respectively, the colelctor electrode of T1, T3 extremely links to each other with "+" of dc source, and the emitter stage of T2, T4 extremely links to each other with "-" of dc source.Electromagnetic stove power 8kw, power output is adjustable continuously from 1.5kw-8kw.T1, T2, T3, T4 adopt the IGBT module of withstand voltage 1200V, electric current 75A, and resonant capacitance C is the noninductive electric capacity of the big electric current of the high frequency of withstand voltage 1200V, and heater coil is that anti-500 ℃ high temperature wire coiling forms.During electromagnetic stove work, the full-bridge circuit that T1, T2, T3, T4 form is under driving pulse drives, output 25KHZ square-wave voltage is added to the elementary of pulse power output transformer B, after the impedance conversion, series resonant tank by the secondary drive of B is made up of heater coil L and resonance capacitor C has resonance current to pass through among the L, pass through electromagnetic induction, make the iron pan that is placed on the heater coil L induce eddy current, make the iron pan heating.

Claims

1, a kind of three-phase electromagnetic kitchen range that utilizes the pulse power output transformer, it is characterized in that, mate full bridge power pipe T1, T2, T3, T4 and heater coil L with pulse power output transformer B, wherein the elementary two ends of pulse power output transformer B are connected with the emitter stage of power tube T1, T3 respectively, the secondary two ends of pulse power output transformer B are connected with heater coil L, resonant capacitance C under the series connection respectively, the colelctor electrode of T1, T3 extremely links to each other with "+" of dc source, and the emitter stage of T2, T4 extremely links to each other with "-" of dc source.