CN2557845Y - Digital program controller for flexible electric heater - Google Patents

Abstract

The utility model is a digital program controller for flexible electrical heaters, comprising a power supply, a sensor circuit and an executive circuit (7) which are connected with a control circuit (3); the executive circuit (7) is connected with an electric heating layer (8) of an electric heater (2); the control circuit (3) is a single chip microcomputer (IC1); the single chip microcomputer (IC1) and a temperature-setting input circuit (12) and a time-setting input circuit (11) are connected with a memory (5). The memory (5) is an integrated circuit (IC2).The digital program controller is of simple structure and convenient operation, which can memorize the temperature that is selected by the operator and assume time and can realize accurate measurement and control.

Description

Flexible electric heating digital process controller

Technical field:

The utility model is relevant with the digital process control device of the flexible electric heating that adopts double-deck (or three layers) spiral heating line and temp.-sensing wire.

Technical background:

Existing multifunctional electro-heating blanket fuzzy controller, by the working power part, control circuit, peripheral sensing and power driving circuit are formed.Sort controller does not have the numeral of operating temperature and working time to set, do not have the function of numeral demonstration and data-storing, automatically the temperature selected of memory operation person and regularly, the operational data that is not easy to feed back to producer's electric blanket is beneficial to pinpoint the problems and electric blanket is made improvements.And the temperature that sort controller detects is the temperature of some point of electric blanket, can not accurately measure and control whole temperature rise of electric blanket all sidedly, is difficult to carry out safeguard protection when too high when abnormal operating state local temperature rise appears in electric blanket.

The content of utility model:

The purpose of this utility model provide a kind of can be in extended menory the temperature selected of memory operation person and regularly automatically, be convenient to the user and set and observed data, be convenient to producer and take out the flexible electric heating digital process controller that memory is analyzed the electric heater duty.

Another purpose of the present utility model is to make controller can accurately measure and control whole temperature rise of electric blanket.

The utility model is achieved in that

The utility model flexible electric heating comprises power supply with the digital process controller, sensing circuit that is connected with control circuit (3) and executive circuit (7), and executive circuit (7) is connected with the heating wire layer (8) of electric heater (2), and control circuit (3) is single-chip microcomputer (IC ₁), single-chip microcomputer (IC ₁) set input circuit (12) with temperature, time set input circuit (11) is connected with memory (5).Memory (5) is integrated circuit (IC ₂), be the EEPROM memory of expansion.

Integrated circuit (IC ₂) pin (1,2,3,4,7) all connect the negative terminal of direct voltage source (14), pin (8) connects the anode of direct voltage source (14), pin (5,6) connects single-chip microcomputer (IC respectively ₁) pin (1,2), resistance (R ₁₀, R ₁₁) an end connect the anode of direct voltage source (14), the other end connects single-chip microcomputer (IC respectively ₁) pin (2,1) constitute single-chip microcomputer (IC ₁) extended menory (5).

Sensing circuit comprises constant current source (13), the temp.-sensing wire (R of the temp.-sensing wire layer (9) of electric heater (2) _f) be connected the positive-negative output end of constant current source (13) and single-chip microcomputer (IC with the positive and negative output of constant current source (13) ₁) pin (3,5) connect.

Power control circuit (15) has a utmost point, the resistance (R of fuse (Fu) and bipolar power supply switch (SA) ₁) series connection back and resistance (R ₂) and electric capacity (C ₁) parallel circuit serial connection, again with the rectifier bridge (VD of direct voltage source (14) ₁-4) a input connects, the other end of bipolar power supply switch and rectifier bridge (VD ₁-4) another input connects, and direct voltage source (14) has three terminal regulator (IC ₄) and stream bridge (VD ₁-4) positive-negative output end connects, electric capacity (C ₄) be connected to three terminal regulator (IC ₄) 2 pin and 3 pin between, C ₄Two ends respectively with single-chip microcomputer (IC ₁) pin (16,5) connect.

Constant current source (13) has voltage-stabiliser tube (VW ₂), diode (VD ₈) and resistance (R ₃) be connected in series in the positive and negative end of direct voltage source (14), diode (VD ₈) and resistance (R ₃) tie point meet NPN triode (VT ₁) base stage, triode (VT ₁) collector series resistance (R ₄) connect the anode of direct voltage source (14), temp.-sensing wire (R _f) be connected (VT by binding post ₁) emitter stage and the negative terminal of direct voltage source (14) between, electric capacity (C in parallel ₅, C ₆) in parallel with temp.-sensing wire and meet single-chip microcomputer (IC ₁) and pin (3,5), electric capacity (C in parallel ₇, C ₈) the negative terminal of a termination direct voltage source (14), its other end meets single-chip microcomputer (IC respectively ₁) pin (17,18), ceramic resonator (H) is connected (IC ₁) pin (17,18) between.

Executive circuit (7) and single-chip microcomputer (IC ₁) between optical coupling isolator (6) is arranged, optical coupling isolator is integrated circuit (IC ₃), integrated circuit (IC ₃) input port 1 pin and single-chip microcomputer (IC ₁) 13 pin connect integrated circuit (IC ₃) delivery outlet 4 pin series resistance (R ₇) meet the anode and the diode (VD of controllable silicon (SCR) ₅), its 6 pin forward series diode (VD ₆) connect the control utmost point of controllable silicon (SCR), constituted executive circuit (7), the heater wire of the heating wire layer (8) of heater (2) is by binding post and diode (VD ₅) parallel connection, resistance (R ₉) and electric capacity (C ₉) series connection back is in parallel with controllable silicon (SCR), heater wire is connected with power control circuit (15).

Single-chip microcomputer (IC ₁) pin (15,14,20,19) be connected with digital display (4).

Parameter write circuit (10) and single-chip microcomputer (IC are arranged ₁) connect resistance (R ₁₂, R ₁₆, R ₁₃, R ₁₇, R ₁₄, IC ₁₈, R ₁₅, R ₁₉) respectively with switch (SB ₁, SB ₂, SB ₃, SB ₄) be serially connected with between the positive and negative end of direct voltage source (14), the tie point of two resistance respectively with single-chip microcomputer (IC ₁) pin (8,9,10,11) connect into time set input circuit (11), temperature is set input circuit (12) and parameter write circuit (10).

Single-chip microcomputer (IC ₁) be EM78P458, integrated circuit (IC ₂) be 24C02, integrated circuit (IC ₂) be the eeprom memory AT24C02 of expansion.

The utility model is simple in structure, and is easy to manufacture, easy to use.Because single-chip microcomputer is set with numeral, digital display circuit is connected, and has a memory of expansion, be convenient to the numeral that numeral is set and observation post sets that the user carries out operating temperature and time, controller can be stored temperature and the timing that the user selects automatically in the single-chip microcomputer extended menory, have online rewriting and power failure data hold function, easy to use, and be convenient to producer and reclaim the electric heater operational data and study.Because connecting stable constant-current source is added on the temperature-sensitive helix with the parallel coiling of spiral hot line, trickle temperature resistiveization can both be write by the single-chip microcomputer collection, carry out digitized processing, accurately the variations in temperature of whole of complete detection flexible electric heating tool and realize accurately measuring and control.Owing to adopted the constant-current source technology, the temperature resistance discretization error of the temperature-sensitive helix that brings owing to the reason of making can accurately be measured by single-chip microcomputer, realizes thermometric program compensation correcting process, thereby has simplified the debug process in producing, and reduces production costs.

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:

Digital process control circuit of the present utility model is by comprising single chip circuit, extended menory circuit; Light-emitting diode display circuit, optically-coupled buffer circuit, temperature are set input circuit, work timing input circuit, parameter write circuit, power drive executive circuit, power supply step-down control circuit, DC voltage source circuit and constant-current source circuit totally 11 element circuits compositions.Current fuse FU, 1 utmost point of bipolar power supply switch S A, resistance R ₁After the series connection again with R ₂With the parallel circuit serial connection of capacitor C 1, supply voltage is connected on rectifier bridge VD by another utmost point of this series circuit and SA _1-4On two inputs, constitute power supply step-down control loop.Voltage-stabiliser tube VW ₁, capacitor C ₂And C ₃Be parallel to rectifier bridge VD _1-4Output, rectifier bridge VD _1-4Positive output termination 5V three terminal regulator IC ₄1 pin, rectifier bridge VD _1-4Negative output terminal connect three terminal regulator IC ₄3 pin, capacitor C ₄Be connected on three terminal regulator IC ₄2 pin, 3 pin between constituted DC5V DC voltage source circuit.IC ₄2 pin be that the anode of DC5V connects single-chip microcomputer IC ₁16 pin, IC ₄3 pin be that the negative terminal of DC5V connects single-chip microcomputer IC ₁5 pin, constitute single-chip microcomputer IC ₁Current supply circuit.Voltage-stabiliser tube VW ₂, diode VD ₈And R ₃The DC5V DC voltage source circuit that is connected in series positive and negative terminal, VD ₈And R ₃Tie point meets PNP triode VT ₁Base stage, VT ₁Colelctor electrode series connection R ₄, meeting DV5V, temp.-sensing wire Rf is by binding post G ₁, G ₂Be connected VT ₁Emitter stage and the DC5V negative terminal between, and and capacitor C ₅, C ₆Formation constant current source circuit in parallel.VT ₁Emitter stage connect single-chip microcomputer IC ₁3 pin constitute thermometric Δ mv signal input circuit.Capacitor C ₇, C ₈A termination DC5V negative terminal, C ₇, C ₈The other end meet single-chip microcomputer IC respectively ₁17,18 pin, the IC that ceramic resonator H also is connected ₁17,18 pin between constitute the clock oscillation loop.Memory IC ₂1,2,3,4 and 7 pin all connect the DC5V negative terminal, 8 pin connect the DC5V anode, 5 pin are connected single-chip microcomputer IC respectively with 6 pin ₁1 pin and 2 pin, resistance R ₁₀And R ₁₁An end with connecing the DC5V anode, 1 pin and 2 pin that the other end connects single-chip microcomputer respectively constitute single-chip microcomputer IC ₁The extended menory loop.PNP triode VT ₂The former LED-1 charactron DIG.1 pin that connects of current collection, emitter stage connects the DC5V negative terminal, base stage series resistor R ₂₂15 pin that connect single-chip microcomputer constitute temperature demonstration tens position and select the loop.PNP triode VT ₃Colelctor electrode connects LED-1 charactron DIG.2 pin, and emitter stage connects the DC5V negative terminal, base stage series resistor R ₂₈Order sheet IC ₁14 pin of machine constitute temperature demonstration units position and select the loop.NPN triode VT ₃Colelctor electrode connects LED-2 charactron DIG, 1 pin, and emitter stage connects the DC5V negative terminal, base stage series resistor R ₂₉Meet single-chip microcomputer IC ₁20 pin constitute and to show that regularly the tens position selects the loop.PNP triode VT ₅Colelctor electrode connects LED-2 charactron DIG.2 pin, and emitter stage connects the DC5V negative terminal, base stage series resistor R ₃₀Meet single-chip microcomputer IC ₁19 pin constitute and to show that regularly the units position selects the loop.Single-chip microcomputer IC ₁4 pin connect resistance R ₂₀, R ₂₀Another termination LED charactron D section constitutes section and selects the D loop.Single-chip microcomputer IC ₁6 pin connect resistance R ₂₁, R ₂₁Another termination LED charactron E section constitutes section and selects the E loop.Single-chip microcomputer IC ₁7 pin connect resistance R ₂₂, R ₂₂Another termination LED charactron C section constitutes section and selects the C loop.Single-chip microcomputer IC ₁8 pin connect resistance R ₂₃, R ₂₃Another termination LED charactron A section constitutes section and selects the A loop.Single-chip microcomputer IC ₁9 pin connect resistance R ₂₄, R ₂₄Another termination LED charactron F section constitutes section and selects the F loop.Single-chip microcomputer IC ₁10 pin connect resistance R ₂₅, R ₂₅Another termination LED charactron G section constitutes section and selects the G loop.Single-chip microcomputer IC ₁11 pin connect resistance R ₂₆, R ₂₆Another termination LED charactron B section constitutes section and selects the B loop.Resistance R ₁₂, R ₁₆Touch-switch SB ₁Be serially connected between the DC5V positive and negative terminal resistance R ₁₂, R ₁₆Tie point and single-chip microcomputer IC ₁8 pin connect and compose with section and select the timing input circuit of the shared I/O mouth in A loop.Resistance R ₁₃, R ₁₇With touch-switch SB ₂Be serially connected in DC5V positive and negative between, resistance R ₁₃, R ₁₇Tie point and single-chip microcomputer IC ₁9 pin connect and compose with section and select the temperature of the shared I/O mouth in F loop to set (subtraction) input circuit.Resistance R ₁₄, R ₁₈And touch-switch SB3 is serially connected between the DC5V positive and negative terminal resistance R ₁₄, R ₁₈Tie point and the IC of single-chip microcomputer ₁10 pin connect and compose with section and select the temperature of the shared I/O mouth in G loop to set (addition) input circuit.Resistance R ₁₅, R ₁₉And touch-switch SB4 is serially connected between the DC5V positive and negative terminal resistance R ₁₅, R ₁₉Tie point and 11 pin of single-chip microcomputer connect and compose the temperature sensor parameter input selection circuit that selects the shared I/O mouth in B loop with section.Diode VD ₉, VD ₁₀, VD ₁₁And VD ₁₂Negative pole connect touch-switch SB respectively ₁, SB ₂, SB ₃And SB ₄, its positive pole all connects the negative pole of news Chinese percussion instrument HA, the positive pole serial connection R of HA ₃₁And C ₁₀Parallel circuit and DC5V anode join and constitute button sound equipment prompting loop.Single-chip microcomputer IC ₁PWM delivery outlet 13 pin series resistor R ₆With photo-coupler IC ₃Input port 1 pin join IC ₃2 pin connect the DV5V negative terminal and constitute PWM control output loop.Resistance R ₅With light emitting diode LD series connection at single-chip microcomputer IC ₁PWM delivery outlet 13 pin and the DC5V negative terminal between constitute PWM output show circuit.Diode VD ₅Oppositely with the series connection of unidirectional controllable silicon S CR forward between bipolar power supply switch S A the two poles of the earth, the heating line of family expenses flexible electric heating tool passes through binding post H ₂, H ₁With diode VD ₅Parallel connection, resistance R ₉With capacitor C ₉The serial connection back is in parallel with controllable silicon SCR, resistance R ₈Connect the control utmost point and the negative electrode of SCR, photo-coupler IC respectively with two ends after the diode V7 parallel connection ₃Delivery outlet 4 pin series resistor R7 connect the controllable silicon SCR anode, 6 pin forward series diode VD6 connect the SCR control utmost point, have constituted the power drive executive circuit.Wherein, photo-coupler IC ₃Isolated～potential difference of 220V forceful electric power and DC5V light current.

Whole units, device that above-mentioned digital process control circuit adopts are installed on the printed circuit board, and device is in controller housing.The outer casing frontispiece top has the position of transparent window over against LED charactron and light emitting diode LD.The push button of power switch SA and touch-switch SB ₁, SB ₂, SB ₃Knob be installed in outer casing frontispiece.

Its operation principle is when power switch SA connects, and～220V 50Hz alternating voltage promptly puts on the circuit of controllable silicon SCR and heating line EH series connection, at this moment, and single-chip microcomputer IC ₁The output of triggerless voltage, controllable silicon is conducting not.Simultaneously ,～220V 50Hz alternating voltage also has been added in by R ₁, R ₂, R ₃With rectifier bridge VD _1-4On the step-down rectifying circuit that is composed in series.R ₁At filter capacitor C ₂When not setting up, terminal voltage plays the peak limiting electric current.R ₁And C ₁Step-down in parallel makes rectifier bridge VD _1-4Input voltage pact～12V.The rectification output dc voltage is through voltage-stabiliser tube VW ₁, C ₂And C ₃Behind the limit filtration DC9V.Through three terminal regulator IC ₄, capacitor C ₄1 exports the direct voltage source of stable DC5V voltage as this circuit again after width of cloth filtering.Voltage-stabiliser tube VW ₂, diode VD ₈And R ₃Series circuit is to triode VT ₁Provide a stable base voltage, from triode VT ₁Colelctor electrode flows to temp.-sensing wire R _FElectric current I R _FBe constant, therefore at R _FThe voltage VR that two ends form _FOnly and R _FResistance relevant.When the temperature of heating line EH rises or descends when changing, temp.-sensing wire R _FThe size of the resistance value variations in temperature of also following heating line EH.At R _FThe voltage that two ends form is V _RF+ Δ mv is by single-chip microcomputer IC ₁Collection writes, through regulating behind the sequential operation from the occupation efficiency of the controllable silicon SCR trigger voltage of 13 pin output, need that constant temperature is just kept current dutyfactor value, needs heat up or cooling just the result data change dutyfactor value by computing is big or little, through one by one to V _RF+ Δ mv gathers and to write computing and constantly to regulate the occupation efficiency of controllable silicon SCR trigger voltage, progressively forces the temperature that the step author sets and moves constant temperature output.Thermometric, temperature-controlled precision depend on single-chip microcomputer IC ₁The A/D conversion accuracy.This circuit uses EM78P458 type single-chip microcomputer, its 8 A/D converters and temp.-sensing wire R _FThe adaptive back of temperature resistance rate of change resolution reaches 0.3 ℃.Satisfy the requirement of family expenses flexible electric heating tool temperature control technique fully.Single-chip microcomputer IC ₁The follow procedure instruction writes V from 3 pin collections _RF+ Δ mv, from the PWM voltage of the adjustable amplitude 4.5V of 13 pin output duty cycles as the controllable silicon SCR trigger voltage.The PWM voltage duty cycle is followed the difference size of design temperature and observed temperature, changes within 0-100%, and PWM voltage is through photo-coupler IC ₃After change into the time scale functional switch of following PWM voltage, through R ₇And VD ₆Connect the controllable silicon SCR anode and the control utmost point.Regulate the time scale of the turn-on and turn-off of controllable silicon SCR, also just regulated the heating power of heater wire EH, thereby the realization temperature is controlled automatically.R ₇Be the current-limiting protection SCR control utmost point, VD ₆Blocking-up～220V backward voltage plays protection IC ₃Effect.R ₉, C ₉And R ₈, VD ₇All are the improper voltage effects of restriction.VD ₅Effect be to form the big current loop of half-wave when imitating when SCR punctures to change, fusing protective tube FU finishes the protection of cutting off the electricity supply.IC ₂Be the eeprom memory of expansion, this circuit uses model ATZ4C02, finishes online rewriting and power failure data hold function in circuit, R ₁₀, R ₁₁It is its data wire pull-up resistor.The frequency of ceramic resonator H is got 3.58M, can satisfy this circuit computing sequential.The luminous demonstration of conducting of this circuit LED charactron is finished with position, section ordering circulation energising.R among the figure ₂₇And VT ₂Circuit is selected in the position that is temperature demonstration LED tens, works as IC ₁Programmed instruction when choosing this, 15 pin output high potential, VT ₂Conducting, this selected section is all luminous.Other is by R ₃₀And VT ₅, R ₂₈And VT ₃, R ₂₉And VT ₄The position of forming selects the circuit working principle identical.Seven of four LED sections are connected in parallel R in circuit ₂₀～R ₂₆It is respectively the current-limiting resistance of seven sections.Work as IC ₁Programmed instruction when choosing this section, corresponding I/O mouth output high potential, luminous when at this moment four LED correspondent section choosings all on the throne are chosen.Timing input circuit R ₁₂, R ₁₆With touch-switch SB ₁Series connection, SB ₁The attitude attitude is disconnected, and it is that high potential is represented not have timing data and write that single-chip microcomputer detects I/O mouth 8 pin.Work as SB ₁During connection, I/O mouth 8 pin are limited to electronegative potential, and it is that electronegative potential promptly writes and regularly adds " 1 " that single-chip microcomputer detects I/O mouth 8 pin.All the other 3 Data In-Line principles are all imported identical with timing in the circuit.4 Data In-Lines select the shared I/O mouth in loop with 4 sections respectively, be to be to write data by SCM program instruction difference, or deferent segment select current potential.Single-chip microcomputer IC ₁The temperature that writes is set and the timing setting data are deposited in memory, as temperature control, timing computing parameter and LED video data.HA is miniature news Chinese percussion instrument, works as SB _1-4When having one to connect arbitrarily, C ₁₀Even charging current HA sends clear melodious sound equipment, prompting operation success, R ₃₁Be C ₁₀Discharge resistance.

Claims (9)

1, flexible electric heating digital process controller comprises power supply, sensing circuit that is connected with control circuit (3) and executive circuit (7), and executive circuit (7) is connected with the heating wire layer (8) of electric heater (2), and control circuit (3) is single-chip microcomputer (IC ₁), single-chip microcomputer (IC ₁) set input circuit (12) with temperature, time set input circuit (11) is connected with memory (5), and memory (5) is integrated circuit (IC ₂), be the EEPROM memory of expansion.

2, controller according to claim 1 is characterized in that integrated circuit (IC ₂) pin (1,2,3,4,7) all connect the negative terminal of direct voltage source (14), pin (8) connects the anode of direct voltage source (14), pin (5,6) connects single-chip microcomputer (IC respectively ₁) pin (1,2), resistance (R ₁₀, R ₁₁) an end connect the anode of direct voltage source (14), the other end connects single-chip microcomputer (IC respectively ₁) pin (2,1) constitute single-chip microcomputer (IC ₁) extended menory (5).

3, controller according to claim 1, it is characterized in that sensing circuit comprises constant current source (13), the temp.-sensing wire (Rf) of the temp.-sensing wire layer (9) of electric heater (2) is connected the positive-negative output end of constant current source (13) and single-chip microcomputer (IC with the positive and negative output of constant current source (13) ₁) pin (3,5) connect.

4, controller according to claim 1 is characterized in that power control circuit (15) has a utmost point, the resistance (R of fuse (Fu) and bipolar power supply switch (SA) ₁) series connection back and resistance (R ₂) and electric capacity (C ₁) parallel circuit serial connection, again with the rectifier bridge (VD of direct voltage source (14) ₁-4) a input connects, the other end of bipolar power supply switch and rectifier bridge (VD ₁-4) another input connects, and direct voltage source (14) has three terminal regulator (IC ₄) and stream bridge (VD ₁-4) positive-negative output end connects, electric capacity (C ₄) be connected to three terminal regulator (IC ₄) 2 pin and 3 pin between, C ₄Two ends respectively with single-chip microcomputer (IC ₁) pin (16,5) connect.

5, controller according to claim 1 is characterized in that constant current source (13) has voltage-stabiliser tube (VW ₂), diode (VD ₈) and resistance (R ₃) be connected in series in the positive and negative end diode of direct voltage source (14), (VD ₈) and resistance (R ₃) tie point meet NPN triode (VT ₁) base stage, triode (VT ₁) collector series resistance (R ₄) connect stream voltage source (14) anode, temp.-sensing wire (R _f) be connected (VT by binding post ₁) emitter stage and the negative terminal of direct voltage source (14) between, electric capacity (C in parallel ₅, C ₆) in parallel with temp.-sensing wire and meet single-chip microcomputer (IC ₁) and pin (3,5), electric capacity in parallel ( _C7, C ₈) the negative terminal of a termination direct voltage source (14), its other end meets single-chip microcomputer (IC respectively ₁) pin (17,18), ceramic resonator (H) is connected (IC ₁) pin (17,18) between.

6, controller according to claim 1 is characterized in that executive circuit (7) and single-chip microcomputer (IC ₁) between optical coupling isolator (6) is arranged, optical coupling isolator is integrated circuit (IC ₃), integrated circuit (IC ₃) input port 1 pin and single-chip microcomputer (IC ₁) 13 pin connect integrated circuit (IC ₃) delivery outlet 4 pin series resistance (R ₇) meet the anode and the diode (VD of controllable silicon (SCR) ₅), its 6 pin forward series diode (VD ₆) connect the control utmost point of controllable silicon (SCR), constituted executive circuit (7), the heater wire of the heating wire layer (8) of heater (2) is by binding post and diode (VD ₅) parallel connection, resistance (R ₉) and electric capacity (C ₉) series connection back is in parallel with controllable silicon (SCR), heater wire is connected with power control circuit (15).

7, controller according to claim 1 is characterized in that single-chip microcomputer (IC ₁) pin (15,14,20,19) be connected with digital display (4).

8, controller according to claim 1 is characterized in that having parameter write circuit (10) and single-chip microcomputer (IC ₁) connect resistance (R ₁₂, R ₁₆, R ₁₃, R ₁₇, R ₁₄, IC ₁₈, R ₁₅, R ₁₉) respectively with switch (SB ₁, SB ₂, SB ₃, SB ₄) be serially connected with between the positive and negative end of direct voltage source (14), the tie point of two resistance respectively with single-chip microcomputer (IC ₁) pin (8,9,10,11) connect into time set input circuit (11), temperature is set input circuit (12) and parameter write circuit (10).

9, controller according to claim 1 is characterized in that single-chip microcomputer (IC ₁) be EM78P458, integrated circuit (IC ₂) be 24C02, integrated circuit (IC ₂) be the eeprom memory AT24C02 of expansion.

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