CN2669032Y - Control device for electromagnetic stove - Google Patents

Abstract

The utility model discloses a control device for electromagnetic stove, respectively comprising a power-supply alternating direct current filter circuit, an alternating current power-supply voltage detection circuit, an alternating current power supply voltage transient state spike detection and protection circuit, an oscillation high voltage peak value detection and protection circuit, a load current detection circuit, an IGBT temperature detection circuit, a stove surface temperature detection circuit, an oscillation frequency and phase detection and protection circuit, an IGBT drive circuit, an LC oscillation circuit, a human-machine interface circuit, a single chip min-computer and a control circuit regulated power supply. Each part is connected electrically. It is characterized in that all keys of the human-machine interface circuit are divided into two groups; one end of each group of keys is a parallel common end; the two common ends are respectively electrically connected with the data end and the clock end of a serial code converter 74LS164; the other ends of all keys, after being connected with resistors in series, are respectively electrically connected with Q0-Q7 mouths of the serial code converter 74LS164 to realize 16 keys without increasing extra single chip min-computer interface resources; consequently, circuit design is simplified further and the cost is lowered.

Description

Electromagnetic oven control device

Technical field

The utility model relates to a kind of electromagnetic oven control device, belongs to electromagnetic stove.

Background technology

Electromagnetic stove circuit on the market adopts buffering and the expansion of serial decoding device 74LS164 as the single chip microcomputer interface at present.Usually, the common port of button will take mouth line of single chip microcomputer, circuit complexity, production cost height separately.

Summary of the invention

The purpose of this utility model designs at the problem that above-mentioned battery kitchen range exists, in this electromagnet kitchen range scheme, for saving the single chip microcomputer port cost, originally the common port of button is received data terminal and the clock end of 74LS164 respectively, make full use of the reading scan circuit resource, only using 6 single chip microcomputer I/O mouth lines, four triodes, a 74LS164 integrated circuit, scanning is lighted when reaching 34 luminous tubes, realize nearly 16 buttons, but additionally do not increase the single chip microcomputer interface resource, thereby circuit design is simplified more, reduce cost.

The purpose of this utility model is achieved in that a kind of electromagnetic oven control device; respectively by power supply alternating current-direct current filter circuit; the AC supply voltage testing circuit; the AC supply voltage transient peak detects and holding circuit; the vibration high-pressure peak detects and holding circuit; load current detection circuit; the IGBT temperature sensing circuit; the furnace surface temperature testing circuit; frequency of oscillation; phase-detection and holding circuit; the IGBT drive circuit; the LC oscillating circuit; the man-machine interface circuit; single chip microcomputer; the control circuit voltage-stabilized power supply is formed; each part is electrically connected; it is characterized in that: all buttons of man-machine interface circuit are divided into two groups; each is organized an end of button and connects and is common port; two common ports are electrically connected with data terminal and the clock end of serial decoding device 74LS164 respectively; behind the resistance, the Q0～Q7 mouth with serial decoding device 74LS164 is electrically connected respectively on the other end string of all buttons.

The utlity model has following advantage: only using 6 single chip microcomputer I/O mouth lines, four triodes, a 74LS164 integrated circuit, scanning is lighted when reaching 34 luminous tubes, realize nearly 16 buttons, but additionally do not increase the single chip microcomputer interface resource, thereby make circuit design simplify more, reduce cost.

Below in conjunction with the drawings and specific embodiments the utility model is described in further detail.

Description of drawings

Fig. 1 is a block diagram of the present utility model;

Fig. 2 is circuit theory diagrams of the present utility model.

The specific embodiment

As shown in Figure 1 and Figure 2; a kind of electromagnetic oven control device is detected by power supply alternating current-direct current filter circuit 1, AC supply voltage testing circuit 2, AC supply voltage transient peak respectively and holding circuit 3, that the vibration high-pressure peak detects is little with holding circuit 4, load current detection circuit 5, IGBT temperature sensing circuit 6, furnace surface temperature testing circuit 7, frequency of oscillation, phase-detection and holding circuit 8, IGBT drive circuit 9, LC oscillating circuit 10, man-machine interface circuit 11, monolithic

Computer 12, control circuit voltage-stabilized power supply 13 are formed, each part is electrically connected, it is characterized in that: all buttons of man-machine interface circuit 11 are divided into two groups, each is organized an end of button and connects and is common port, two common ports are electrically connected with data terminal and the clock end of serial decoding device 74LS164 respectively, behind the resistance, the Q0 ~ Q7 mouth with serial decoding device 74LS164 is electrically connected respectively on the other end string of all buttons.Operation principle of the present utility model is such, and after the electromagnetic stove energising, single chip microcomputer promptly enters duty through the electrification reset process, and peripheral signal is detected, and the man-machine interface circuit is reacted.After single chip microcomputer detected start key presses, single chip microcomputer entered an inspection pot sequence immediately, and single chip microcomputer sends a pulse signal, by the IGBT drive circuit, drives IGBT, entered the free damping vibration after making oscillating circuit charging accumulation of energy.If pot is arranged or bigger Ferrious material is arranged, because the coil panel of oscillating circuit induces eddy current on pan, free oscillation must decay very soon, otherwise, if do not have pan or just the metal small articles is on the electromagnetic stove table top, free oscillation must decay slowly relatively.By detecting the power of attenuation degree, promptly whether decidable electromagnetic stove table top is placed with pan, if pot is arranged, single chip microcomputer then sends a little driving pulse, treats that attenuation oscillasion impulse experiences first vibration wave head, when oscillating to wave base (trough), promptly send second driving pulse ...So, go round and begin again, progressively strengthen (broadening) pulse, reach setting value up to power, and regulate according to load and mains voltage variations situation at any time, because the energy of electromagnetic induction and eddy current is bigger, the direct current waveform of supplying with oscillating circuit originally will become (the waveform that 20 ~ 30kHz) attenuation sinusoidal wave is compound about frequency 100Hz half-sinusoid and frequency 25kHz by straight.Because the variation of line voltage and frequency, environment temperature, load, all influence complex oscillation wave frequency, amplitude, phase place, therefore, single chip microcomputer must carry out real-time monitoring with microsecond level or above speed, accurately carry out real-time locking phase control, to suppress generating noise.Above-mentioned is the operation principle of battery kitchen range, for ease of understanding, each built-up circuit to the battery kitchen range is further detailed: AC supply voltage detects, directly alternating current 220V voltage is introduced with two 1N4007 diodes, behind electric resistance partial pressure and capacitance-resistance filter, send single chip microcomputer A/D input interface, detect AC supply voltage.The speed-up capacitor (102P/500V) in parallel at 200k/0.5W resistance two ends, introduce LM339 comparator (B) reverse input end (6 pin), detect the AC power transient peak, and pass through the output of comparator (B), block the IGBT drive circuit and send signal to single chip microcomputer.Load current detection circuit makes Current Transformer detect main circuit current, send single chip microcomputer A/D input interface after rectification, filtering, detects load current.The IGBT temperature sensing circuit is formed bleeder circuit with 100k/3990 thermistor and 6.2k metalfilmresistor, connects one 104 ceramic disc capacitor shapings, directly receives single chip microcomputer A/D input interface.The furnace surface temperature testing circuit is formed bleeder circuit with 100k/3990 thermistor and 6.2k metalfilmresistor, connects one 104 ceramic disc capacitor shapings, directly receives single chip microcomputer A/D input interface.High direct voltage detects and protection; take a sample from IGBT colelctor electrode (the c utmost point); through electric resistance partial pressure; the ceramic disc capacitor shaping; introduce LM339 comparator (D) reverse input end (8 pin); detect high direct voltage, and pass through the output of comparator (B), block the IGBT drive circuit and send signal to single chip microcomputer.Frequency of oscillation, phase-detection and holding circuit are benchmark with LC oscillating circuit dc power supply terminal, through electric resistance partial pressure, introduce LM339 comparator (C) input (9 pin), device reference voltage as a comparison in the same way; Simultaneously, use the 4.3V voltage-stabiliser tube, receive single chip microcomputer, as the detection reference commutation circuit by diode.From LC oscillating circuit charge switch end, i.e. IGBT colelctor electrode (the c utmost point) sampling through electric resistance partial pressure, is introduced LM339 comparator (C) reverse input end (8 pin).By resistance, the diode of comparator (C) output (14 pin),, constitute frequency of oscillation, phase-detection and holding circuit with single chip microcomputer interface and the coupling of IGBT drive circuit.The man-machine interface circuit adopts buffering and the expansion of 74LS164 serial decoding device as the single chip microcomputer interface.Usually, the common port of button will take mouth line of single chip microcomputer separately.But in the utility model scheme, for saving the single chip microcomputer port cost, originally the common port of button is received data terminal and the clock end of 74LS164 respectively, make full use of the reading scan circuit resource, only using 6 single chip microcomputer I/O mouth lines, four triodes, a 74LS164 integrated circuit, scanning is lighted when reaching 34 luminous tubes, realize nearly 16 buttons, but overhead single chip microcomputer interface resource not, thus make circuit design simplify more, reduce cost.

Claims (2)

1; a kind of electromagnetic oven control device; respectively by power supply alternating current-direct current filter circuit (1); AC supply voltage testing circuit (2); the AC supply voltage transient peak detects and holding circuit (3); the vibration high-pressure peak detects and holding circuit (4); load current detection circuit (5); IGBT temperature sensing circuit (6); furnace surface temperature testing circuit (7); frequency of oscillation; phase-detection and holding circuit (8); IGBT drive circuit (9); LC oscillating circuit (10); man-machine interface circuit (11); single chip microcomputer (12); control circuit voltage-stabilized power supply (13) is formed; each part is electrically connected; it is characterized in that: all buttons of man-machine interface circuit (11) are divided into two groups; each is organized an end of button and connects and is common port; two common ports are electrically connected with the data terminal and the clock end of serial decoding device respectively; on the other end string of all buttons behind the resistance, respectively with being electrically connected of serial decoding device.

2, electromagnetic oven control device according to claim 1, it is characterized in that described two common ports are electrically connected with data terminal and the clock end of serial decoding device 74LS164 respectively, behind the resistance, the Q0～Q7 mouth with serial decoding device 74LS164 is electrically connected respectively on the other end string of all buttons.

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