CN2053420U

CN2053420U - Electromagnetically inductive heater

Info

Publication number: CN2053420U
Application number: CN 89205302
Authority: CN
Inventors: 周志伟
Original assignee: Individual
Current assignee: Individual
Priority date: 1989-08-09
Filing date: 1989-08-09
Publication date: 1990-02-21

Abstract

The utility model discloses an electromagnetic induction heater mainly for cooking food in family, hotel, etc. The utility model is composed of a main circuit, a control circuit and a range body. An induction heating coil in the main circuit and a capacitor compose a parallel resonance circuit. After the parallel resonance circuit is connected in series with a static thyristor and an inductor, the parallel resonance circuit is connected to a direct current power supply. The utility model has the advantages of simple structure, low power consumption and high thermal efficiency, and the utility model can be cooperated with ferromagnetic heating utensils of various specifications and shapes.

Description

Electromagnetically inductive heater

The utility model relates to a kind of electromagnetic induction heater, mainly is applicable to non-industrialness heating object and cooking foods such as family, restaurant.

Existing electromagnetic induction heater utilizes the conducting of large power triode usually and ends, and periodically to load coil and capacitances to supply power, forms alternating magnetic field and comes heating object.Specially permit out hope as Japan and announce clear 63-25473 and specially permit out hope and disclose the disclosed electromagnetic induction heater of clear 61-45591, be direct mode of heating, than the heat efficiency height of indirect mode.But because of large power triode two ends Fan Xiang the diode of And connection when triode bears reverse voltage with the conducting consumed power, the whole time that needs conducting at triode, its base stage all need consume certain power, and the conducting of triode and by being subject to the influence of external circuit, these all will increase the power consumption of circuit.

Task of the present utility model provides a kind of electromagnetic induction heater, and it can further reduce the power consumption of induction heater, carries high thermal efficiency And and makes structure more simple.

Task of the present utility model is finished with the following method: with the large power triode in the alternative main circuit of controllable silicon.Load coil and Dian Rong And connection ， Ci And connection circuit one end is connected with power supply, the other end is received the silicon controlled negative electrode, the silicon controlled anode with receive on the power supply after inductance is connected.By load coil with the frequency of the resonance frequency of And connection electric capacity decision controllable silicon triggering and conducting, make power cycle ground by controllable silicon to load coil power supply And Xing Cheng And connection resonance between load coil and electric capacity, produce the high frequency alternating flux thus and pass heating vessel and come heating object.

Because itself has positive feedback effect controllable silicon, after it was triggered conducting, its negative electrode and the pressure drop of anode two ends were stabilized in about 1 volt, made external circuit not prolong its opening process, and along with the controllable silicon shortening of service time, the institute of controllable silicon wasted work rate own will reduce.Because of the controllable silicon in this heater bears reverse voltage, electric current is zero and turn-off naturally, does not also need extra power during shutoff, and the controllable silicon two ends do not need instead to join diode to And, so it is low that circuit power of the present utility model consumes, structure is also simpler.

Below with reference to accompanying drawing the utility model is described in further detail.

Fig. 1 is a kind of electrical schematic diagram of the utility model.

Fig. 2 is the electric circuit diagram of a kind of control circuit of the utility model.

With reference to accompanying drawing, the utility model mainly is made up of several parts of main circuit, control circuit and stove.220 volts of alternating currents become DC power supply after rectification, filtering.Load coil L in the main circuit (1) ₄And capacitor C ₂The negative electrode K that And connection ， Ci And connection circuit one end links to each other with DC power supply, the other end is received controllable silicon KK, the anode A of controllable silicon KK and inductance L ₃Receive on the DC power supply after the series connection.

Starting circuit and phase detecting circuit are arranged in the control circuit of the present utility model.Starting circuit of the present utility model is by voltage transformer L ₃, reverser (2) and pulse generator (3) form.Inverter (2) is by bridge rectifier D ₁～D ₄, capacitor C ₆, voltage-stabiliser tube DW ₁With switch triode T ₁Constitute.As voltage transformer L ₅When both end voltage is zero, inverter (2) output high level, pulse generator (3) sends positive pulse, makes silicon controlled toggle system generation trigger impulse, controllable silicon KK conducting, resonant circuit is started working; As voltage transformer L ₅When there was an alternating voltage at two ends, this alternating voltage was through D ₁～D ₄Bridge rectifier, capacitor C ₆, resistance R ₁Filtering, voltage-stabiliser tube DW ₁Slicing output high level is again through switch triode T ₁Output low level oppositely, pulse generator (3) stops to send pulse.

Phase detecting circuit of the present utility model is used to control controllable silicon KK at load coil L ₄And capacitor C ₂The opportunity of conducting during resonance is mainly by voltage transformer L ₆, diode D ₅, voltage-stabiliser tube DW ₂, resistance R ₇And Schmidt trigger (4) is formed.Work as capacitor C ₂With load coil L ₄When resonance takes place, voltage transformer L ₆Two ends will induce alternating voltage.Work as capacitor C ₂When the polarity of both end voltage is identical with electric power polarity, diode D ₅Export corresponding half-wave voltage, through voltage-stabiliser tube DW ₂Slicing is by resistance R ₇, R ₈Capacitor C ₇Lag behind and export the input of forward voltage, Schmidt trigger (4) output positive pulse to Schmidt trigger (4).Change resistance R ₇Resistance just can change the opportunity that controllable silicon KK triggers, change the power of induction heater thus.Monostable trigger (5) and power amplifier (6) constitute the trigger system of controllable silicon KK.Positive pulse by starting circuit or phase detecting circuit output inputs to monostable trigger (5), the pulse And that is sent the required triggering width of controllable silicon KK by monostable trigger (5) adds between the control utmost point G and negative electrode K of controllable silicon KK through power amplifier (6), makes controllable silicon KK be in conducting state.When controllable silicon KK is subjected to reverse voltage, it will be in off state.Load coil L ₄And capacitor C ₂Determined the frequency of controllable silicon KK triggering and conducting.With reference to Fig. 1, controllable silicon KK can select fast controllable silicon for use, and its on-state average current is 10～30 amperes, oppositely ceiling voltage is 450～1000 volts.Load coil L ₄With multiply copper cash or enamelled wire coiling, its inductance value is 1.56～0.021 milihenries.Inductance L ₃Inductance value be load coil L ₄1/4～1/10, comparatively desirable.Capacitor C ₂Adopt the polypropylene metal film electric capacity of 15.2～0.15 microfarads.With reference to Fig. 2, switch triode T ₁, T ₂, T ₃, T ₄, T ₅, T ₆Model select 3DK5A type, T for use ₇Adopt the 3DA15A type.BT in the pulse generator (3) adopts BT33 type unijunction transistor.The output signal of starting circuit and phase detecting circuit be " or " state, by D ₆And D ₇Two diodes constitute, and select 2CK73 type diode for use.The utility model can have protective devices such as overload, zero load with the ferromagnetism heating vessel adapted ， And of all size, shape.

Claims

1, a kind of electromagnetic induction heater is made up of several parts of main circuit, control circuit and stove, it is characterized in that the load coil L in the main circuit ₄And capacitor C ₂The negative electrode K that And connection ， Ci And connection circuit one end is connected with power supply, the other end is received controllable silicon KK, the anode A of controllable silicon KK and inductance L ₃Receive on the power supply after the series connection.