CN101596074B - Relay control device and cooking machine - Google Patents

Abstract

The present invention provides a relay control device and a cooking machine. In a relay control device for controlling a relay for loads such as a heater, and the like, an output voltage can be set not related to effects of capacitor capacity, relay coil resistance, and the like at a switching time from a voltage over an induced for supplying an induced current to a voltage over a holding voltagefor supplying a holding current, thereby ensuring that it can be used in the long-term. An alternating current power supply is switched into a direct current power supply by a first direct current power supply circuit (4), and then switched into more lower voltage than the voltage output by a first direct current power supply circuit through a second direct current power supply circuit (14), the on-off of the relay is controlled by a controller (15), the first direct current power supply circuit has a plurality of output voltages, and the driving electric power of the relay is supplied by a first current power supply circuit according to a control signal of the controller.

Description

Relay control device and cooking machine

Technical field

The cooking machine that the present invention relates to a kind of relay control device of the heater even load being controlled by relay and comprise this relay control device.

Background technology

In the past, when the heater even load is controlled with relay, be used for driving the power circuit of relay to adopt following control method: while in the coil of relay, there is no current flowing, the voltage that output is higher than the induced voltage of relay; And, when the coil of relay has current flowing, export than relay induced electricity and force down but keep the voltage that voltage is high (example wherein can with reference to Japanese Unexamined Patent Publication 8-266800) than relay

In the above referred-to references, be used for driving the voltage of voltage regulation circuit that the power circuit of relay is comprised of commutation diode, resistance, Zener diode and smmothing capacitor to form, and the output voltage of this power circuit is detected, when output voltage when determined output voltage is above, just make relay start to connect, thereby shorten AC power, be switched to the time that relay drives.Simultaneously, when relay coil has electric current to flow through, reduce the output voltage of power circuit, reduce the electric current of relay coil, thereby suppressed the heating of relay coil.

But, adopt such circuit to form, for having electric current to flow through in relay coil and not having electric current to flow through, the output voltage of corresponding power circuit will change, and the capacity of the capacity of the smmothing capacitor be connected with the output of power circuit like this or the capacitor be connected in parallel at the relay coil two ends need to be designed to optimum value.Yet, because capacitor time one is long, can occur deterioratedly, the time constant of capacitor and coil will diminish, and exists the problem that time (in other words conj.or perhaps relay coil being applied the time of induced voltage) that the induced-current of relay flows through can shorten.

In addition, if consider long can occur deteriorated of capacitor time one, the faradic flushing time of relay still can be guaranteed for many years later, the capacity of capacitor just must increase, capacitor also will maximize, and can bring like this device volume to become large problem.

Also have, when relay coil does not have electric current to flow through, be used for driving the supply voltage of relay to increase, the voltage be added on other circuit components outside relay also increases, and the electric current that other circuit components outside relay flow through also increases along with executing alive increasing.Like this, when the coil of relay does not have electric current to flow through that is device while not using, the power consumption in the time of can standby occurring is also by the problem increased.

Summary of the invention

The present invention makes in order to solve problems of the prior art, set switching instant that output voltage carries out to the voltage that can supply with more than the maintenance voltage that keeps electric current from the voltage that can supply with more than faradic induced voltage can with condenser capacity, the impact such as relay-coil resistance is irrelevant, thereby can guarantee that long-term the use is the first purpose of the present invention.

Also have, relay can use for a long time, and it is the second purpose of the present invention that the cooking machine that a kind of product life is very long is provided.

In order to reach the first purpose, relay control device of the present invention comes conducting or disconnection by relay in the current path of load and AC power, AC power switches to dc source by the first DC power supply circuit, the output voltage of the first DC power supply circuit is transformed into the voltage lower than the output voltage of the first DC power supply circuit by the second DC power supply circuit, by the control part that is carried out the electric power supply by the second DC power supply circuit, conducting and the disconnection of relay is controlled.The first DC power supply circuit has a plurality of output voltages, and the driving electric power of relay will be supplied with by the first DC power supply circuit according to the control signal of control part.Control part is when the relay conducting, set the output voltage of the first DC power supply circuit for can supply with value more than the faradic induced voltage of relay, from the relay conducting, start to the stipulated time, the output voltage of the first DC power supply circuit is set as supplying with the above value of maintenance voltage that relay keeps electric current.

Like this, according to the relay ON time, control part can switch the output voltage that relay coil is carried out to the first DC power supply circuit of electric current supply, so, can set the switching instant that output voltage carries out to the voltage that can supply with more than the maintenance voltage that keeps electric current from the voltage that can supply with more than faradic induced voltage, do not formed the condenser capacity of the first DC power supply circuit, the impacts such as relay-coil resistance, the formation component capacitor that simultaneously also is not subject to the first DC power supply circuit deteriorated impact all the year round, can guarantee the long-term use of relay control device.

Also have, cooking machine of the present invention, in order to reach above-mentioned the second purpose, include above-mentioned relay control device.

Therefore, because relay can use for a long time, can provide the cooking machine that a kind of product life is very long.

The technique effect that the present invention produces is as follows.Relay control device of the present invention can be set the output voltage of the power circuit (the first DC power supply circuit) of supplying with the relay coil electric current by control part, control part can be to the output voltage of the first dc source of supplying with the relay coil electric current according to the relay ON time, be switched to by the voltage that can supply with more than faradic induced voltage the voltage that can supply with more than the maintenance voltage that keeps electric current, the capacitor that will not be subject to like this to form component as the first DC power supply circuit deteriorated impact all the year round, can guarantee the component miniaturization, relay control device also can guarantee long-term use.

In addition, cooking machine of the present invention, because relay can use for a long time, can provide the cooking machine that a kind of product life is very long.

The specific embodiment of the invention plan explanation is as follows.Relay control device in the present invention's the 1st scheme comprises: AC power, load, the current path of above-mentioned load and above-mentioned AC power is carried out to the relay of conducting or disconnection, above-mentioned AC power is converted to the first DC power supply circuit of dc source, the output voltage of above-mentioned the first DC power supply circuit is switched to second DC power supply circuit lower than the first DC power supply circuit voltage, with being undertaken by the second DC power supply circuit, electric power is supplied with and the conducting of control relay and the control part of disconnection.Above-mentioned the first DC power supply circuit has a plurality of output voltages, the driving electric power of above-mentioned relay is supplied with by the first DC power supply circuit according to the control signal of control part, above-mentioned control part is when above-mentioned relay conducting, the output voltage of the first DC power supply circuit is set as supplying with the value more than the faradic induced voltage of relay, start to the stipulated time from the relay conducting, the output voltage of the first DC power supply circuit is set as supplying with the value more than the maintenance voltage that relay keeps electric current.Like this, control part can be switched the output voltage of the first DC power supply circuit of supplying with the relay coil electric current according to the ON time of relay, so, output voltage carries out switching instant by the voltage that can supply with more than faradic induced voltage to the voltage that can supply with more than the maintenance voltage that keeps electric current, can be set as the condenser capacity that is not subject to form the first DC power supply circuit, the impacts such as the resistance of relay coil, therefore be not subject to the first DC power supply circuit to form the deteriorated impact all the year round of component capacitor yet, can guarantee the long-term use of relay control device.In addition, in the situation that the relay ON time is very long, the output voltage of the first DC power supply circuit also can be less than the induced voltage of relay, larger than maintenance voltage, and the output voltage of the second DC power supply circuit is also very low, like this, the consumption electric power of relay control device also can be very little.

The 2nd scheme is, on the basis of the 1st scheme, relay control device is, when control part disconnects at relay, the output voltage of setting the first DC power supply circuit is than supplying with the voltage that faradic induced voltage is lower, and the output voltage of above-mentioned the first DC power supply circuit is set as more than induced voltage being worth before the relay conducting, like this, because the output voltage step-down of the second DC power supply circuit, the consumption electric power of the second DC power supply circuit has also reduced, electric power when relay control device stops moving, that is to say that stand-by electric also can reduce.

The 3rd scheme is, on the basis of the 2nd scheme, relay control device is, when control part disconnects at relay, the output voltage of setting the first DC power supply circuit is the lower voltage of maintenance voltage than supplying with the maintenance electric current, when relay disconnects, even control part sends the control signal of conducting under the impact of foeign element, the contact of supplying with electric current due to relay coil does not connect, thereby when can provide a kind of relay control device to be failure to actuate, the contact of relay can not connect the relay control device of the safety of load conducting mistakenly.Also have, because the voltage of the second dc source output is very low, the consumption electric power of the second DC power supply circuit is also just very low, can reduce the stand-by electric of relay control device.

The 4th scheme is that, on the basis of the 1st scheme, relay control device also comprises the voltage detection department that detects the first DC power supply circuit voltage.Control part is when the relay conducting, and the voltage that above-mentioned voltage detection department detects is when the induced voltage of above-mentioned relay is following, and control relay does not start conducting, thereby can prevent the generation of relay induced-current undersupply state when conducting.In addition, by using the electric current less than induced-current, carry out turn-on relay, can prevent the generation that relay tip is bad.

The 5th scheme is, on the basis of the 1st scheme, relay control device also comprises for producing and the no-voltage synchronizing signal generating unit of the signal that the no-voltage of AC power is synchronous, being used for measuring the timer of above-mentioned no-voltage synchronizing signal generating unit output time, the timing setting section be used for to being set to the period of relay conducting or disconnection from no-voltage synchronizing signal generating unit output signal.The output of the period that control part is set according to above-mentioned timing setting section and above-mentioned timing section carrys out conducting and the disconnection of control relay, above-mentioned timing setting section equally carries out the rotation change by the sign change of the phase place of above-mentioned similar AC power of period, like this, flow into the current average of relay tip close to zero, suppress the transfer of relay tip metal, improved the durability of relay tip.

The 6th scheme is that, on the basis of the 1st scheme, relay control device comprises a plurality of loads, a plurality of relays that the current path of above-mentioned a plurality of loads and AC power carried out respectively to conducting or disconnection.Control part is in above-mentioned a plurality of relays during a conducting, no matter other relay is in conducting state or off-state, the output voltage of the first DC power supply circuit will be set as supplying with the above value of the faradic induced voltage of above-mentioned relay, then, at the appointed time, the output voltage of the first DC power supply circuit will be set as supplying with the above value of maintenance voltage that above-mentioned relay keeps electric current, so also just there is no need the most suitable circuit to each relay additional services relay coil electric current, can reduce the component of forming circuit.In addition, when the relay conducting, at first, the output voltage of the first DC power supply circuit will switch to the above value that can supply with the faradic induced voltage of relay, in stipulated time after the relay conducting, the output voltage of the first DC power supply circuit will switch to the above value of the maintenance voltage of the maintenance electric current that can supply with relay, thus, relay control device is irrelevant with relay quantity, can guarantee that relay is moved in action assurance scope, thereby can improve the reliability of relay control device.

The 7th scheme is that, on the basis of the 6th scheme, relay control device also comprises the plural relay that induced-current is different.Control part is when the relay conducting, in the middle of above-mentioned different induced-current, can supply with the output voltage that maximum faradic induced voltage is set as the first DC power supply circuit, can reduce like this setting value number of the output voltage of the first DC power supply circuit, also can reduce the formation component of relay control device, the control of relay can be simpler.Also have, because can flow through the above electric current of maximum induced-current in the induced-current of a plurality of relays, even the different relay of induced-current is switched on simultaneously, the induced-current that relay also can not occur is not enough, relay tip connects non-persistent state, thereby can prevent the bad of the relay such as relay tip failure welding.

The 8th scheme is that, on the basis of the 7th scheme, relay control device comprises the different plural relay of maintenance electric current.Control part is when the relay conducting, in the middle of above-mentioned different induced-current, can supply with the output voltage that maximum faradic induced voltage is set as the first DC power supply circuit, after relay is conducting to the stipulated time, above-mentioned different the maintenance in the middle of electric current, the maintenance voltage that can supply with maximum maintenance electric current is set as the output voltage of the first DC power supply circuit, can reduce like this setting value number of the output voltage of the first DC power supply circuit, also can reduce the formation component of relay control device, the control of relay can be simpler.Because can flow through the maximum above electric current of electric current that keeps in the maintenance electric current of a plurality of relays, even keep the different relay of electric current to be switched on simultaneously, also can prevent the maintenance undercurrent of relay, because connection that can not the guard relay contact can not be switched on load.Also have, also can suppress due to relay keep undercurrent cause can not the guard relay contact connection, produce as a result the contact that electric spark causes by electric spark between the separation of relay tip, relay tip soldered.

The 9th scheme is that, on the basis of the 1st scheme, relay control device comprises near the temperature detecting part of the detected temperatures of relay.Control part will be according to the output of said temperature test section, change the output voltage of the first DC power supply circuit, even the resistance of relay is because ambient temperature changes, the output voltage of the first DC power supply circuit also can change according to the variation of this environment temperature detected, can guarantee relay induced-current and the normal supply that keeps electric current, also can prevent that relay tip can not be connected, thereby can prevent from can not being switched on because contact can not keep the load that separates and then cause.

The cooking machine of the 10th scheme comprises the relay control device of wantonly 1 scheme record in above-mentioned 1-9 scheme.Because relay can use for a long time, can provide the cooking machine that a kind of product life is very long.Also have, because cooking machine etc. all will be heated, temperature while usually using around relay control device all can be very high, it is generally acknowledged that electrolytic capacitor can be more easily more aging than AV machine etc., like this, by control part, the output voltage of the first DC power supply circuit is set, because this output voltage can be switched, when setting the capacity of capacitor, just there is no need to consider faradic flushing time and the consumption electric power of relay, can only consider electrolytic capacitor deteriorated problem all the year round.

The accompanying drawing explanation

The part block diagram of the relay control device that Fig. 1 is the embodiment of the present invention 1 circuit diagram,

Fig. 2 is the sectional view that the cooking machine of above-mentioned relay control device is housed,

The time sequential routine figure that Fig. 3 is above-mentioned relay control device,

The part block diagram of the relay control device that Fig. 4 is the embodiment of the present invention 2 circuit diagram,

Fig. 5 is the electric cooker sectional view as the cooking machine of above-mentioned relay control device is housed,

Part operation sequential (first half) schematic diagram that Fig. 6 is above-mentioned relay control device,

Part operation sequential (latter half) schematic diagram that Fig. 7 is above-mentioned relay control device.

Wherein, 1 is AC power, and 2 is heater (load), and 3 is relay tip, and 13 is relay coil (relay), and 14 is the second DC power supply circuit, and 115 is control part.

The specific embodiment

With reference to the accompanying drawings specific embodiments of the invention are elaborated.In addition, embodiments of the invention do not have the effect that limits the scope of the invention.

(embodiment 1)

The part block diagram of the relay control device that Fig. 1 is the embodiment of the present invention 1 circuit diagram.Fig. 2 is the sectional view that the cooking machine of above-mentioned relay control device is housed, and has omitted status of electrically connecting in Fig. 2.

In Fig. 1, AC power 1 is mains supply, take Japan as example, general use be 60HZ 100V or 50HZ/100V.Heater 2 forms load, and the tubulose spiral heater be comprised of Nie Chrome alloy wire forms, and produces near infrared ray.This heater is when adding the voltage of 100V, and power is about 400W.Also have, although the tubulose spiral heater that the Shi Nie Chrome alloy wire used in the present embodiment forms can use halogen heater, also can use the argon gas heater.Relay tip 3 is connected with heater 2, carrys out the break-make of the current path of control heater 2 and AC power 1 by the switching of relay tip 3.

The first DC power supply circuit 4, for AC power 1 is switched to dc source, comprises halfwave rectifier smoothing circuit 7 and Switching Power Supply 8.Halfwave rectifier smoothing circuit 7 is formed by diode 5 and capacitor 6.Switching Power Supply 8 is accepted the electric power of halfwave rectifier smoothing circuit 7 and is supplied with and export the 12V DC voltage.Halfwave rectifier smoothing circuit 7 is that to use diode 5 and 6 pairs of AC powers of capacitor 1 to carry out halfwave rectifier level and smooth, and switching is into about the DC voltage of 141V.But this is only an example, it is also smoothly no problem adopting bridge diode that AC power 1 is carried out to full-wave rectification.

Switching Power Supply 8 comprises: by MOSFET constant power semiconductor unit with in fixed current value range, power semiconductor is carried out the built-in control circuit 9 of power semiconductor that the control circuit (not shown) of open and close controlling forms, coil 10, smmothing capacitor 11 and is made as the output voltage detecting circuit 12 that the fixed setting value control circuit built-in to power semiconductor 9 carries out FEEDBACK CONTROL for the voltage by capacitor 11.

The built-in circuit 9 of power semiconductor carries out open and close controlling in the scope of determined current value by the MOSFET to built-in, through 10 pairs of capacitors 12 of coil, charged.

Although do not illustrate in figure, output voltage detecting circuit 12 comprises photoelectric coupling circuit, 12V Zener diode and 7V Zener diode.Thereby the switching of being undertaken by these two Zener diodes switching is by the output voltage of FEEDBACK CONTROL.

For example, when output voltage is set as about 12V, photoelectric coupling circuit and Zener diode series connection.When the voltage of capacitor 11 surpasses 12V, the energising of 12V Zener diode, the photoelectric coupling circuit conducting, send to the built-in control circuit 9 of power semiconductor the signal that output voltage surpasses 12V, after the built-in control circuit 9 of power semiconductor is received signal, the switch of built-in MOSFET disconnects, and stops the power supply to capacitor 11, voltage drop; When lower than 12V, the 12V Zener diode is by no power, photoelectric coupling circuit disconnects, send the signal of output voltage lower than 12V to the built-in control circuit 9 of power semiconductor, after the built-in control circuit 9 of power semiconductor is received signal, the switch conduction of built-in MOSFET, charged through 10 pairs of capacitors 11 of coil.

When output voltage is set as about 7V, photoelectric coupling circuit and the series connection of 7V Zener diode, carry out and top same action.In addition, the output voltage detecting circuit in the present embodiment 12 will be elaborated afterwards.

In other words, the Switching Power Supply in the present embodiment 8 is depressured to the output voltage of the approximately 141V of halfwave rectifier smoothing circuit 7 DC voltage of about 12V.

A terminal of relay coil (relay) 13 is connected with the lead-out terminal of the first DC power supply circuit 4.In the present embodiment, the rated voltage of relay coil 13 is 12V.Also have, the DC voltage (induced voltage) that can produce induced-current (being that relay tip is connected to guarantee the driven electric current of relay) is 10V, and (Hold current: the DC voltage irreducible minimum electric current that relay can keep) (maintenance voltage) is 5V can to produce the maintenance electric current.

Although do not illustrate in the drawings, the emitter base diode circuit that the second DC power supply circuit 14 is comprised of NPN transistor and Zener diode forms, for the output voltage by Switching Power Supply 8 namely the about 12V of output voltage of the first DC power supply circuit 4 switch to the voltage that is about 5V lower than the output voltage of the first DC power supply circuit 4.

Control part 15 consists of micro computer 16, the drive circuit 17 of being powered to relay coil 13, output voltage setting device 18 that the output voltage of the first DC power supply circuit 4 is set etc.This control part 15 is when the second DC power supply circuit 14 is supplied with the DC voltage of about 5V and work.Micro computer 16 is to high signal or the low signal of energising or the disconnection of drive circuit 17 output control relay coils 13.

In the relay control device of the present embodiment, micro computer 16, to the high or low signal of output voltage setting device 18 output, is switched the detection voltage setting value of the output voltage detecting circuit of the first DC power supply circuit 4 12.In the present embodiment, when the output voltage setting value of the first DC power supply circuit is 12V, micro computer 16 is to output voltage setting device 18 output low signals; When the output voltage setting value of the first DC power supply circuit is 7V, to the high signal of output voltage setting device 18 output.

The relay control device of the present embodiment 16 li of micro computers built-in timer, from relay coil 13 energisings, start to carry out timing, after reaching the stipulated time, will be switched to the signal of output voltage setting device 18 outputs.

Drive circuit 17 consists of transistor etc., and during transistor turns, the 12V output voltage of Switching Power Supply 8 is powered to relay coil 13, the interior generation current of relay coil 13 thus, and the electromagnetic force produced by coil drives the contact 3 of relay.

In general, for relay, when relay coil 13 is applied to rated voltage, can produce and be greater than faradic electric current.Therefore, if adopt the relay that the rated voltage of relay coil is 12V, relay tip 3 just can connect reliably.

Here " induced-current " refers to the current value of the relay coil 13 that can make relay tip 3 actions and connect reliably, and this current value is also the specification of relay, is general ground commonly used term.

Output voltage setting device 18 consists of transistor etc., switches the detection voltage setting value of output voltage detecting circuit 12 by transistorized break-make.In the relay control device of the present embodiment, while forming the transistor turns of output voltage setting device 18, the detection voltage of output voltage detecting circuit 12 is 7V; When transistor disconnects, the detection voltage of output voltage detecting circuit 12 is 12V.

As shown in Figure 2, cooking machine body 21 forms case shape structure by the metallic plate of surface process electroplating processes, and heating clamber 22 is the casings that can only open towards a direction that formed by aluminium sheet.In the inside of heating clamber 22, end face and bottom surface are equipped with heater 2 (spiral heater), and these two heaters are and are connected in series on circuit.

Door 23 consists of glass and metallic plate, thereby can make the user can be by the visual gratin state of seeing heating clamber 22 inside.Handle 24 is formed by resin, even because the heating of heater 2 causes door 23 temperature to rise, the user also can catch handle that door is opened or closed.

Relay control device as shown in Figure 1 is installed on control circuit board 25.In the main circuit of the relay control device shown in pie graph 1, except heater 2, some other circuit also is installed, as display units such as the switch such as components and parts that heater 2 is controlled, the thermistor that detects heating clamber 22 internal temperatures, touch-switch and LED.After the user presses the operation button, cooking machine operating process is according to the rules operated.

Guidance panel 26 is provided in a side of the operation part on control circuit board 25, and the user can set desirable mode of operation and time by it.In addition, guidance panel 26 also means to be located at the light emitting diode on control circuit board 25, allows the user can see remaining time and present state.

Roast net 27 is formed by metal, although do not show in the drawings, four angles of Roast net 27 are provided with hook, and these hooks are arranged on assigned position after Roast net 27 is hung up.Machine leg 28 is formed by resin, is arranged on four angles of cooking machine body 21.

Below with reference to Fig. 3, operational circumstances and the effect of the cooking machine of relay control device that the present embodiment is housed are described.

The operation waveform sequential chart that Fig. 3 is each several part in the relay control device shown in Fig. 1.Wherein, (a) be the on off state schematic diagram of drive circuit 16, (b) be the current waveform schematic diagram of heater 2 and relay tip 3, (c) be the output voltage waveforms schematic diagram of the first DC power supply circuit 4, (d) be the on off state schematic diagram of output voltage setting device 17, (e) be the voltage waveform view of AC power 1.

During operation, at first, on the Roast net 27 of user in the heating clamber 22 shown in Fig. 2, place the gratins such as bread, sesame seed cake.At this moment, the relay control device of Fig. 1 is connected (connection) with AC power 1.Micro computer 16 in control part 15 sends high signal to output voltage setting device 18.The transistor of output voltage setting device 18 receives conducting after high signal, and during transistor turns, the detection voltage setting value of output voltage detecting circuit 12 is just 7V, and so just can controlling the first DC power supply circuit 4, to make its output voltage be 7V.

During above-mentioned state, while according to the demonstration on guidance panel 26, pressing desirable switch, just can press the switch on control circuit board 25 by guidance panel 26, just can start with the corresponding heating of switch.

For example, when the switch of guidance panel 26 is pressed, in the t0 moment of Fig. 3, the micro computer 16 of control part 15 sends low signal to output voltage setting device 18, the transistor of output voltage setting device 18 disconnects after receiving low signal, the detection voltage setting value that forms the output voltage detecting circuit 12 of the first DC power supply circuit 4 is just 12V, so just can control the first DC power supply circuit 4 and make its output voltage 12V.

The supply capacity of output voltage changes to 12V time from 7V by the output current of the first DC power supply circuit 4 determined.In the present embodiment, output voltage changes to by 7V the time that 12V needs 30ms.

T1 starts the moment after 40ms from the transistor shutoff of output voltage setting device 18 constantly.At moment t1, the micro computer 16 that forms control part 15 sends high signal to drive circuit 17.Simultaneously, micro computer 16 uses built-in timer to start timing.

During transistor turns in drive circuit 17, relay coil 13 energisings.At this moment, the electric current of relay coil 13 is supplied with by the first DC power supply circuit 4.Because the output voltage of the first DC power supply circuit 4 is controlled so as to 12V, even relay coil 13 has electric current to flow through, voltage can not descend yet.

During relay coil 13 energising, the electromagnetic force that coil produces drives the contact 3 of relay.But, because contact 3 is that mechanical movement realizes connecting, disconnecting, make connection, the heater 2 of relay tip 3 be switched on and need to spend the regular hour.In the present embodiment, constantly, the contact of each relay is connected large t2 after 7ms, and the current path of heater 2 is switched on.

T3 has passed through about 170ms constantly constantly for t1.The built-in timer of micro computer 16 use is to carrying out during this period of time timing, when minute reaches 170ms, to the high signal of output voltage setting device 18 output.

The transistor that forms output voltage setting device 18 receives conducting after this high signal, the detection voltage setting value of the output voltage detecting circuit 12 in the first DC power supply circuit 4 becomes 7V, and so just can controlling the first DC power supply circuit 4, to make its output voltage be 7V.

In the output voltage of the first DC power supply circuit 4 is reduced to the process of 7V by 12V, the built-in control circuit 9 of power semiconductor does not carry out switch motion.That is output voltage is determined by the capacity of 12V capacitor 11 in the first DC power supply circuit 4 to the 7V required time and the resistance value of relay coil 13.In the present embodiment, output voltage is 25ms by 12V to the 7V required time.In the present embodiment, the DC voltage that can produce the maintenance electric current of relay coil 13 is 5V, as long as the output voltage of the first DC power supply circuit 4, at 7V, just can be supplied with, is greater than the electric current that keeps electric current.Simultaneously, because the output voltage of giving the second DC power supply circuit 14 is 7V, can suppress like this loss of the second DC power supply circuit 14, reduce the power consumption of the relay control device except load (heater 2) electric power.

According to upper type, in the relay control device of the present embodiment, control part 15 is set as the output voltage of the first DC power supply circuit 4 supplying with the value more than the faradic induced voltage of relay when the relay conducting, from relay is conducting to the stipulated time, the output voltage of the first DC power supply circuit 4 is made as to the value more than the maintenance voltage that can supply with relay maintenance electric current simultaneously.Like this, control part 4 can be switched the output voltage of the first DC power supply circuit 4 of supplying with relay coil 13 electric currents according to the relay ON time, even forming the capacity of the capacitor 11 of the first DC power supply circuit 4 increases, also can guarantee that supply voltage is regularly switched according to institute quarter, the current sinking of relay coil 13 and can being inhibited to the loss that control part 15 carries out the second DC power supply circuit 14 of electric power supply, also there is no need current sinking in order to reduce relay coil 13 and on relay coil 13 serial connection current limitation resistance.And, in the situation that be connected in series current limitation resistance, the electric current while starting in order to ensure relay coil and also there is no need to be provided with the capacitor that relay coil is connected in parallel.

Also have, in the relay control device of the present embodiment, as shown in Figure 3, front the first DC power supply circuit 4 outputs of the actuating of relay are forced down than induced electricity, for than the high 7V of maintenance voltage.After being arranged to 7V, the loss of the second DC power supply circuit 14 is few in the time of can be than 12V, reduces power consumption, can reduce standby power consumption in other words.

Also have, the cooking machine of the present embodiment includes above-mentioned relay control device, because relay can use for a long time, therefore can provide a kind of service life very long cooking machine.In addition, cooking machine etc. all will be heated, even as usual use, the environment temperature of relay control device is all higher, can infer at an easy rate, and the electrolytic capacitor in cooking machine can be more easily more aging than the capacitor in AV machine.But, output voltage by the first DC power supply circuit 4 is set by control part 15, because this output voltage can be switched, when setting the capacity of capacitor, just there is no need to consider faradic flushing time and the consumption electric power of relay, can only consider electrolytic capacitor deteriorated problem all the year round.

(embodiment 2)

The part of module circuit diagram that Fig. 4 is the relay control device in embodiments of the invention 2.Fig. 5 is the electric cooker sectional view as the cooking machine of the present embodiment relay control device is housed.In Fig. 5, for drawing has succinctly omitted the screw of using for lead-in wire and the fixed part of electrical connection.

As shown in Figure 4, the primary heater 41 of formation load consists of sheathed heater.In general, sheathed heater is installed the heater such as nickel road alloy wire, is refilled electrical insulators and sealed and make in metal tube.Sheathed heater in the present embodiment is formed, is commonly referred to as the heater of " heater cast " by aluminum casting.This heater cast is when applying 100V voltage, and power is about 400W.Form the secondary heater 42 of load, also consist of sheathed heater, this sheathed heater is when applying 100V voltage, and power is about 70W.

The first relay tip 43 is connected in series with primary heater 41, is controlled conducting and the disconnection of primary heater 41 and AC power 1 current path by the switching of the first relay tip 43.The first relay tip 44 is connected in series with secondary heater 42, is controlled conducting and the disconnection of secondary heater 42 and AC power 1 current path by the switching of the second relay tip 44.

The first DC power supply circuit 45 consists of halfwave rectifier smoothing circuit 7 and Switching Power Supply 46.Halfwave rectifier smoothing circuit 7 consists of diode 5 and capacitor 6.Switching Power Supply 46 is accepted the electric power of halfwave rectifier smoothing circuit 7 and is supplied with and export the 12V DC voltage.

Switching Power Supply 46 comprises: by MOSFET constant power semiconductor unit with this power semiconductor carried out in fixed current value range to the built-in control circuit 9 of power semiconductor, coil 10, the smmothing capacitor 11 that the control circuit (not shown) of switch control forms and the built-in control circuit 9 of power semiconductor carried out to the output voltage detecting circuit 47 of FEEDBACK CONTROL for the voltage by capacitor 11 is made as fixed setting value.

The open and close controlling that the built-in control circuit 9 of power semiconductor carries out in determined current value range by built-in MOSFET, and charged through 10 pairs of capacitors 11 of coil.Although do not illustrate in the drawings, output voltage detecting circuit 47 consists of photoelectric coupling circuit, about 12V Zener diode, about 7V Zener diode, about 4V Zener diode.By these three Zener diodes are switched, the output voltage of FEEDBACK CONTROL is switched.

Specifically, when output voltage is set as about 12V, photoelectric coupling circuit and the series connection of 12V Zener diode, when the voltage of capacitor 11 surpasses 12V, the energising of 12V Zener diode, the photoelectric coupling circuit conducting, send to the built-in control circuit 9 of power semiconductor the signal that output voltage surpasses 12V, after the built-in control circuit 9 of power semiconductor is received signal, the switch of built-in MOSFET cuts out, the electric power of capacitor 11 is supplied with and is stopped, voltage drop, when lower than 12V, the 12V Zener diode is by no power, photoelectric coupling circuit is closed, send the signal of output voltage lower than 12V to the built-in control circuit 9 of power semiconductor, after the built-in control circuit 9 of power semiconductor is received signal, the switch conduction of built-in MOSFET, through 10 pairs of capacitors 11 of coil, charged.

When output voltage is set as 7V, photoelectric coupling circuit and the series connection of 7V Zener diode, carry out and top same action.When output voltage is set as 4V, photoelectric coupling circuit and the series connection of 4V Zener diode, also carry out same action.In addition, the output voltage detecting circuit 47 of the present embodiment will describe afterwards.

In a word, the present embodiment is that Switching Power Supply 46 is depressured to the approximately 141V output voltage of halfwave rectifier smoothing circuit 7 DC voltage of the approximately 12V of Switching Power Supply.

A terminal of the first relay coil (relay) 48 is connected with the lead-out terminal of the first DC power supply circuit 45.In the present embodiment, the rated voltage of the first relay coil 48 is 12V.Also have, can produce faradic DC voltage (induced voltage) is 10V, and the DC voltage (maintenance voltage) that can produce the maintenance electric current is 5V.

A terminal of the second relay coil (relay) 49 is connected with the lead-out terminal of the first DC power supply circuit 45.In the present embodiment, the rated voltage of the second relay coil 49 is 12V.Also have, can produce faradic DC voltage (induced voltage) is 11V, and the DC voltage (maintenance voltage) that can produce the maintenance electric current is 6V.

Control part 50 consists of micro computer 51, the first drive circuit 52 that the first relay coil 48 is switched on, the second drive circuit 53 that the second relay coil 49 is switched on, the output voltage setting device 54 that the output voltage of the first DC power supply circuit 45 is set etc.The approximately 5V DC voltage that this control part 50 relies on the second DC power supply circuit 14 to supply with moves.

Micro computer 51 sends high or low signal to the first drive circuit 52 and the second drive circuit 53, thereby makes the first relay coil 48 and the second relay coil 49 conductings or disconnection.Also have, micro computer 51 also sends signal to output voltage setting device 54, and the detection voltage setting value of the output voltage detecting circuit 47 of the first DC power supply circuit 45 is switched.

The first drive circuit 52 and the second drive circuit 53 consist of transistor etc., and during transistor turns, the output voltage 12V of Switching Power Supply 46 is powered to the first relay coil 48 and the second relay coil 49.Like this, the first relay coil 48 and the interior current flowing of the second relay coil 49, the electromagnetic force that coil produces drives the contact 43 of the first relay and the contact 44 of the second relay.

Output voltage setting device 54 consists of 2 transistors 55,56.By these 2 transistorized break-make combinations, can make the detection voltage setting value of output voltage detecting circuit 47 switch.In the relay control device of the present embodiment, when transistor 55,56 all ends, the detection voltage setting value of output voltage detecting circuit 47 is 12V; While only having transistor 55 conducting, the detection voltage setting value of output voltage detecting circuit 47 is 7V; While only having transistor 56 conducting, the detection voltage setting value of output voltage detecting circuit 47 is 4V.

No-voltage synchronizing signal generating unit 57 is used for occurring and the synchronous signal of no-voltage of AC power 1, comprising: by two resistance resistor voltage divider circuit 58, base stages in series, input transistor 59, the end resistance 60 that with the collector terminal sub-connection of transistor 59 other end with the lead-out terminal of second DC power supply circuit 14 be connected of voltage to carry out switch control from resistor voltage divider circuit 58 dividing potential drops.After adopting above formation, no-voltage synchronizing signal generating unit 57 switches to low signal by high signal at the voltage of AC power 1 near no-voltage, or low signal is switched to high signal.In the relay control device of the present embodiment, the situation that 51 pairs of no-voltage synchronizing signal generating units 57 of micro computer switch to high signal by low signal is detected, and the timer 61 formed by the timing circuit formed in micro computer 51 starts timing.

Timing setting section 62 is used for setting the time period from no-voltage synchronizing signal generating unit 57 output signals to relay conducting or disconnection, and a plurality of time periods that will store in advance in the ROM of micro computer 51 switch in turn.In the relay control device of the present embodiment, will be divided into Ts1, Ts2, Ts3, Ts4 the period.In the present embodiment, according to supply frequency, Ts1, Ts2, Ts3, Ts4 are set as to the time period that phase difference is 90 degree again.That is, when the supply frequency of AC power 1 is 50HZ, Ts1=0ms, Ts2=5ms, Ts3=10ms, Ts4=15ms.Timing setting section 62 switches in turn according to the variation of voltage-phase, from Ts1 to the Ts4 period, is changed.

In the relay control device of the present embodiment, what timer section 61 adopted is built-in timer in the micro computer 51 arranged separately in addition, and the time after the first relay coil 48 or the second relay coil 49 energisings is carried out instrumentation.After the stipulated time, make to switch to the signal of output voltage setting device 18 outputs.

As shown in Figure 5, electric rice cooker body 71 above be provided with can freely openable lid 72.The hinge axis 73 that electric rice cooker body 71 and lid 72 are made by stainless steel carries out mechanical connection.Hinge cap 72 is usingd chain rivet 73 and is opened and closed as rotating shaft.Be provided with pot bottom of 74，Guo resettlement section, resettlement section 74 in electric rice cooker body 71 and be provided with primary heater 41.Primary heater 41 is cast aluminum heaters as shown in Figure 4.

Pot 75 metals by aluminium and so on form.The surface of pot 75 scribbles the fluorine layer.The upper end open section of pot 75 is provided with outward extending flange.Pot 75 states that contact with the top with primary heater 41 are carried, and with the form that can freely put into/take out, are housed in resettlement section 74.The user puts into pot 75 by heating objects such as rice and water, then is cooked.

Lid heating plate 76 is formed by the metal of stainless steel etc., by rubber sheet gasket 77, in mode that can disassembled and assembled freely, is arranged on and covers on 72.The lid heating plate 76 in roughly the position in center be provided with the steam overfolw hole.On the face faced of the lid heating plate 76 on lid 72, aluminum heat liberation board 78 is housed.Secondary heater 42 use aluminum foil and adhesive tape (not shown)s paste on heat liberation board 78, are mounted to heat liberation board 78 and contact.Lid 72 central portion is equipped with steam port 79 that can disassembled and assembled freely, and hole and steam port 79 by lid heating plate 76, discharge the steam of pot 75 interior generations.

The devices such as switch, LCD, micro computer 51 are installed on first circuit board 80.Guidance panel 81 is embedded in electric rice cooker body 71, is printed on the word that means each switch meaning on it.The user presses word segment, just can make the switch be arranged on first circuit board 80 be pressed.

Although do not illustrate in Fig. 5, on second circuit board 82, except the first relay 43, also be equipped with the second relay 44, the first DC power supply circuit 45, the second DC power supply circuit 14 etc.

Rollback type power line resettlement section 83 is connected with second circuit board 82 by wire.Rollback type power line resettlement section 83 makes power line can carry out backrush by block and spring.

Temperature detecting part 84 consists of temperature sensor, and center is omited in the bottom that is arranged on pot 75.Temperature sensor is along with the changes in resistance of temperature also will change, and this temperature sensor forms bleeder circuit with the resistance of regulation resistance, and assigned voltage is added in the bleeder circuit two ends, and the resistance value of temperature sensor just can convert analog voltage to.Micro computer 51 shown in Fig. 4 utilizes built-in AD switch to extrapolate temperature value from this analog voltage.

First circuit board 80 is connected by the wire (not shown) with second circuit board 82.The control of switching on of micro computer 51, the first drive circuit 52 and the second drive circuit 53 pairs of the first relay coils 48, the second relay coils 49, the first relay tip 43, the second relay tip 44 are connected, thereby make primary heater 41, secondary heater 42 conduction/heat releases, thereby pot 75 and lid heating plate 76 are heated.

The electric cooker of the present embodiment is heated pot 75 by the heating of heater 41, and the gratin in pot 75 is carried out to cooking.Rice and water or burned meal before the gratin here refers to and cooks.

Below with reference to Fig. 6 and Fig. 7, operation, the effect of electric cooker that the relay control device with above-mentioned formation is housed are described.The sequential chart of the operation waveform of the each several part that Fig. 6 is the relay control device shown in presentation graphs 4 (first half).Wherein, (a) mean the on off state of the first drive circuit 48, (b) mean the current waveform of primary heater 41 and the first relay tip 43, (c) mean the on off state of the second drive circuit 49, (d) mean the current waveform of secondary heater 42 and the second relay tip 44, (e) mean the output voltage waveforms of the first DC power supply circuit 45, (f) mean the on off state of the transistor 55 of formation output voltage setting device 54, (g) form the on off state of the transistor 56 of output setting device 54, (h) mean the voltage waveform of AC power 1, (i) mean the output signal of no-voltage synchronizing signal generating unit 57.The continuation of the sequential chart of Fig. 7 presentation graphs 6 (later half), (a)～(i) identical with Fig. 6.

At first, the user puts into Mi Heshui in the pot 75 shown in Fig. 5.At this moment, the relay control device of Fig. 4 keeps being connected with AC power 1 always.The micro computer 51 that forms control part 50 sends high signal to the transistor 55 that forms output voltage setting device 54, to transistor 56, sends low signal.Form the transistor 55 of output voltage setting device 54, receive conducting after high signal, the 4V Zener diode that forms output voltage detecting circuit 47z is connected, and the detection voltage setting value is 4V, and so just can controlling the first DC power supply circuit 45, to make its output voltage be 4V.

When the output voltage of the first DC power supply circuit 45 is 4V, the output voltage of the second DC power supply circuit 14 is about 3.3V.This is to consist of emitter base diode circuit because of the second DC power supply circuit 14, and will fall the voltage of 0.7V between the transistorized base-emitter of formation emitter base diode circuit.And the action of the micro computer 51 in the present embodiment guarantees that scope is 2.3V～5.5V, even the output voltage of the second DC power supply circuit 14 is about 3.3V, micro computer 51 also can move normally.

When the output voltage of the first DC power supply circuit 45 is 4V, with output voltage, be that 7V compares during with 12V, the voltage that control part 50 two ends apply is low, even current sinking is identical, the power consumption of control part 50 also can reduce.And the first DC power supply circuit 45 consists of Switching Power Supply 46, the conversion efficiency of DC voltage that is depressured to about 4V from the DC voltage of about 141V is also high a lot of than power transformer, thereby can reduce the power consumption of relay control device.

During above-mentioned state, according to the displaying contents of the guidance panel 81 of Fig. 5, press desirable switch, by guidance panel 81, the switch on first circuit board 80 is pressed, and the corresponding program of cooking of switch has also started.

For example, the switch of push panel 81, in the t0 moment of Fig. 6, the micro computer 51 in control part 50 sends low signal to the transistor 55 in output voltage setting device 54.

Transistor 55 is closed after receiving low signal, and the 12V Zener diode in output voltage detecting circuit 47 is connected, and detecting voltage setting value is just 12V, and so just can controlling the first DC power supply circuit 45, to make its output voltage be 12V.

The time of output voltage from 4V to 12V will be determined by the supply capacity of the output current of the first DC power supply circuit 45.In the present embodiment, output voltage needs the time of about 25ms by 4V to 12V.

Constantly t1 be from transistor 55 is closed through the moment of 40ms, at moment t1, no-voltage synchronizing signal generating unit 57 is sent high signal to micro computer 51.The timer section 61 of micro computer 51 inside starts timing using the edge of high signal as triggering signal, until count the time of setting in timing setting section 62.As described in Figure 4, timing setting section 62 can be set as 4 setting-up time Ts1, Ts2 that store in advance in the built-in ROM of micro computer 51, any setting-up time in Ts3, Ts4.In the present embodiment, have the first relay and the second relay, timing setting section 62 can set the setting-up time of each relay, and the timing setting section 62 while starting of cooking all is set as Ts1 (0ms) to two relays.

At moment t1, because the setting-up time Ts1 that timing setting section 62 sets is 0ms, after no-voltage synchronizing signal generating unit 57 is sent high signal, the micro computer 51 of control part 50 sends high signal to the first drive circuit 52 at once.After sending high signal to the first drive circuit 52, the setting-up time that timing setting section 62 will send high signal to the first drive circuit 52 changes to Ts3 (10ms).With micro computer 51, built-in timer starts timing simultaneously.

During the transistor turns of the first drive circuit 52, the first relay coil 48 energisings.At this moment, the electric current of the first relay coil 48 is supplied with by the first DC power supply circuit 45.Because control the first DC power supply circuit 45 makes its output voltage, be 12V, even the first relay coil 48 has electric current to flow through, voltage does not almost descend yet.

During the first relay coil 48 energising, utilize the electromagnetic force of coil to drive the first relay tip 43.But, after the first relay tip 43 actions, contact is connected, circuit is opened, and the connection of relay tip 43, primary heater 41 conductings will spend the regular hour.In the present embodiment, constantly, the first relay tip 43 is connected large t2 after 7ms, and the current path of primary heater 41 is in conducting state, and the pot 75 that primary heater 41 starts to generate heat to Fig. 5 is heated.

At t3 constantly, t1 passes through about 90ms constantly.51 pairs of micro computers are measured with built-in timer during this period of time, when minute arrives 90ms, to the high signal of transistor 56 output that forms output voltage setting device 54.

Transistor 56 receives conducting after this signal, and the 7V Zener diode in output voltage detecting circuit 47 is connected, and detecting voltage setting value is just 7V, and so just can controlling the first DC power supply circuit 45, to make its output voltage be 7V.

When the output voltage of the first DC power supply circuit 45 is reduced to 7V by 12V, the built-in control circuit 9 of power semiconductor does not carry out on-off action.In a word, output voltage is determined by the capacity of the capacitor 11 that forms the first DC power supply circuit 45 and the resistance of the first relay coil 48 to the 7V required time by 12V.In the present embodiment, output voltage is about 15ms by 12V to the 7V required time.In the present embodiment, the DC voltage that can produce the maintenance electric current of the first relay coil 48 is 5V, as long as the output voltage of the first DC power supply circuit 45 is 7V, just can supply with the electric current that keeps electric current above.Simultaneously, giving the output voltage of the second DC power supply circuit 14 is 7V, can suppress like this loss of the second DC power supply circuit 14, has reduced the power consumption of the relay control device except load (primary heater 41) electric power.

At t4 constantly, for example, the pot 75 interior gratin moisture start vaporizers of Fig. 5, a part of steam on lid heating plate 76 starts dewfall.Now, for the secondary heater 42 that conducting is heated lid heating plate 76, micro computer 51 sends low signal to the transistor 56 of output voltage setting device 54.Transistor 56 is closed after receiving low signal, and the 12V Zener diode of output voltage detecting circuit 47 is connected, and detecting voltage setting value is just 12V, and so just can controlling the first DC power supply circuit 45, to make its output voltage be 12V.

Output voltage becomes the time of 12V and is determined by the resistance of the supply capacity of the output current of the first DC power supply circuit 45, the first relay coil 48 and the capacitor 11 that forms the first DC power supply circuit 45 from 7V.In the present embodiment, output voltage needs the time of about 15ms by 7V to 12V.

T5 closes from transistor 55 moment started through 40ms constantly, and at moment t5, no-voltage synchronizing signal generating unit 57 is sent high signal to micro computer 51.The timer section 61 of micro computer 51 inside is using the edge of high signal as triggering, and timing setting section 62 carries out timing until the time of setting.As described in Figure 4, timing setting section 62 can be set as 4 setting-up time Ts1, Ts2 that store in advance in the built-in ROM of micro computer 51, any setting-up time in Ts3, Ts4.In the present embodiment, have the first relay and the second relay, timing setting section 62 can set the setting-up time of each relay, and the timing setting section 62 while starting of cooking all is set as Ts1 (0ms) to two relays.The second relay conducting is in the period of moment t5, and setting-up time is set as Ts1 (0ms).

At moment t5, because the setting-up time Ts1 that timing setting section 62 sets is 0ms, after the high signal of no-voltage synchronizing signal generating unit 57 output, micro computer 51 sends high signal to the second drive circuit 53 at once.After sending high signal to the second drive circuit 53, timing setting section 62 will change to Ts3 (10ms) to the setting-up time of the high signal of transmission of the second drive circuit 53.With micro computer 51, built-in timer starts timing simultaneously.

The transistor turns of the second drive circuit 53, the second relay coil 49 energisings.At this moment, the electric current of the second relay coil 49 is supplied with by the first DC power supply circuit 45.Because control the first DC power supply circuit 45 makes its output voltage, be 12V, even the second relay coil 49 and the first relay coil 48 have electric current to flow through, voltage does not almost descend yet.

The second relay coil 49 energising the electromagnetic force by coil drive the second relay tip 44.In addition, after the second relay tip 44 actions, contact is connected, and circuit is opened, the connection of the second relay tip 44, and secondary heater 42 is switched on and will spends the regular hour.In the present embodiment, constantly, the second relay tip 44 is connected large t6 after 5～6ms, and the current path of secondary heater 42 is in conducting state, and secondary heater 42 starts heat releases, and the 78 pairs of lid heating plates 76 of lid heat liberation board by Fig. 5 are heated.

T7 passes through about 110ms constantly for t5 constantly.51 pairs of micro computers are measured with built-in timer during this period of time, when minute arrives 90ms, to the high signal of transistor 56 output that forms output voltage setting device 54.

Transistor 56 receives conducting after this signal, and the 7V Zener diode of output voltage detecting circuit 47 is connected, and detecting voltage setting value is just 7V, and so just can controlling the first DC power supply circuit 45, to make its output voltage be 7V.

When the output voltage of the first DC power supply circuit 45 is reduced to 7V by 12V, the built-in control circuit 9 of power semiconductor does not carry out on-off action.That is output voltage is determined by the capacity of the capacitor 11 that forms the first DC power supply circuit 45 and the equivalent resistance of the first relay coil 48 and the second relay coil 49 to the 7V required time by 12V.In the present embodiment, output voltage is about 15ms by 12V to the 7V required time.

In the present embodiment, the DC voltage that can produce the maintenance electric current of the first relay coil 48 and the second relay coil 49 is 5V, as long as the output voltage of the first DC power supply circuit 45 is 7V, just can supply with the electric current that keeps electric current above.Simultaneously, because the output voltage of giving the second DC power supply circuit 14 is 7V, can suppress the loss of the second DC power supply circuit 14 like this, reduce the consumption electric power of the relay control device except load (primary heater 41, secondary heater 42) electric power.

After after a while, primary heater 41 heatings are heated pot 75 bottom surfaces, and the temperature of bottom surface rises.The bottom surface temperature that the temperature detecting part 84 of Fig. 5 detects pot 75 uprises, and by micro computer 51, stops primary heater 41 heating.

Then, at the moment of Fig. 7 t8, no-voltage synchronizing signal generating unit 57 is sent high signal, and the built-in timer section 61 of micro computer 51 starts timing.

At t9 constantly, the instrumentation time of timer section 61 is while reaching setting-up time Ts3 (10ms), micro computer 51 is to the first drive circuit 52 output low signals, and the transistor of the first drive circuit 52 is closed after receiving low signal, and the first relay coil 48 energisings stop.Owing in the first relay coil 48, there is no electric current, the electromagnetic force of coil has not just had yet, and the driving force of the first relay tip 43 has not just had yet, and the first relay tip 43 is just in open state.The first relay tip 43 is in open state, and the current path of primary heater 41 will be disconnected, and primary heater 41 has not just had electric current yet, and the heating of primary heater 41 has also just stopped.

When the bottom surface temperature of pot 75 is low, after temperature detecting part 84 detects, primary heater 41 just is necessary to generate heat again pot 75 is heated.

At t10 constantly, for the first relay coil 48 flows through the electric current more than induced-current, controlling the first DC power supply circuit 45, to make its output voltage be 12V.Micro computer 51 sends low signal to the transistor 56 of output voltage setting device 54, transistor 56 is closed after receiving low signal, the 12V Zener diode that forms output voltage detecting circuit is connected, detect voltage setting value and be set as 12V, so just can controlling the first DC power supply circuit 45, to make its output voltage be 12V.

The time of output voltage from 7V to 12V will be determined by the resistance of the supply capacity of the output current of the first DC power supply circuit 45, the second relay coil 49 and the capacitor 11 that forms the first DC power supply circuit 45.In the present embodiment, output voltage needs the time of about 15ms by 7V to 12V.

T11 is that transistor 56 is from closing the moment started through 40ms constantly.At moment t11, no-voltage synchronizing signal generating unit 57 is sent high signal to micro computer 51, and the timer section 61 of micro computer 51 inside, using the edge of high signal as triggering, starts timing.

At moment t12, when the instrumentation time of timer section 61 reaches timing setting section 62 and sets time T s3 (10ms), micro computer 51 sends high signal to the first drive circuit 52.After sending high signal to the first drive circuit 52, timing setting section 62 will change to Ts2 (5ms) to the setting-up time of the high signal of transmission of the first drive circuit 52.With micro computer 51, built-in timer starts timing simultaneously.

The transistor turns of the first drive circuit 52, the first relay coil 48 energisings.At this moment, the electric current of the first relay coil 48 is supplied with by the first DC power supply circuit 45.Because control the first DC power supply circuit 45 makes its output voltage, be 12V, even the first relay coil 48 and the second relay coil 49 have electric current to flow through, voltage does not almost descend yet.

The first relay coil 48 is switched on, and utilizes the electromagnetic force of coil, and the first relay tip 43 will be connected, and primary heater 41 will be in conducting state.In the present embodiment, constantly, the first relay tip 43 is connected large t13 after 7ms, and the current path of primary heater 41 is in conducting state, and primary heater 41 starts heating pot 75 is heated.

T14 passes through 90ms constantly for t12 constantly.51 pairs of micro computers carry out timing with built-in timer during this period of time, when minute arrives 90ms, to the high signal of transistor 56 output that forms output voltage setting device 54.

Transistor 56 receives conducting after this signal, and the 7V Zener diode of output voltage detecting circuit 47 is connected, and detecting voltage setting value is just 7V, and so just can controlling the first DC power supply circuit 45, to make its output voltage be 7V.

When the output voltage of the first DC power supply circuit 45 is reduced to 7V by 12V, the built-in control circuit 9 of power semiconductor does not carry out on-off action.That is output voltage is determined by the capacity of the capacitor 11 that forms the first DC power supply circuit 45 and the resistance of the first relay coil 48 and the second relay 49 to the 7V required time by 12V.In the present embodiment, output voltage is about 15ms by 12V to the 7V required time.Because can flow through the DC voltage of the maintenance electric current of the first relay coil 48 and the second relay 49 is 5V, as long as the output voltage of the first DC power supply circuit 45 is 7V, just can supply with the electric current that keeps electric current above.Simultaneously, because the output voltage of giving the second DC power supply circuit 14 is 7V, can suppress like this loss of the second DC power supply circuit 14, reduce the consumption electric power of the relay control device except load (primary heater 41) electric power.

Then, when covering the increase in temperature of heating plate 76, micro computer 51 will send and stop heating signal to secondary heater 42.

At t15 constantly, t8 constantly sends high signal to no-voltage synchronizing signal generating unit 57, and the built-in timing section 61 of micro computer 51 starts timing.

At t16 constantly, the instrumentation time of timer section 61 is while reaching setting-up time Ts3 (10ms), micro computer 51 is to the second drive circuit 53 output low signals, and the transistor of the second drive circuit 53 is closed after receiving low signal, and the second relay coil 49 energisings stop.There is no electric current in the second relay coil 49, the electromagnetic force of coil has not just had yet, and the driving force of the second relay tip 44 has not just had yet, and the second relay tip 44 is just in open state.The second relay tip 44 is after open state, and the current path of secondary heater 42 will be disconnected, and secondary heater 42 has not just had electric current yet, and the heating of secondary heater 42 has also just stopped.

According to upper type, the relay control device of the present embodiment refers to, even a plurality of relays are arranged, as long as control the output voltage of the first DC power supply circuit 45 of supplying with the first relay coil 48 and the second relay coil 49 electric currents by control part 50, because supply with the induced-current of relay coil, with the maintenance electric current that can supply with relay coil, can be switched like that according to the moment of hope, so the current sinking of relay coil and just can being inhibited to the loss that control part 50 carries out the second DC power supply circuit 14 of electric power supply.Also have, in order to reduce the current sinking of relay coil, relay coil and current limitation resistance are connected in series, and this just there is no need.And, when current limitation resistance is connected in series, the electric current while starting in order to ensure relay coil, and also there is no need with the capacitor that relay coil has carried out being connected in parallel.

Also have, control part 50 is that the output of period of setting according to timing setting section 62 and timer section 61 comes the conducting of control relay and disconnection, timing setting section 62 is changed the period according to the positive and negative of AC power phase place, like this, flow into the current average of relay tip close to zero, suppress the transfer of relay tip metal, improved the durability of relay tip.

Also have, when all cut-offs, the output voltage that relay is carried out to the first DC power supply circuit of electric current supply will be lower than keeping voltage, even because the impact of foeign element has been exported Continuity signal to relay, also can be because relay coil does not have sufficient electromagnetic force, relay tip cannot connect.

Also have, in the relay control device in the present embodiment, the induced-current of the first relay coil 48 and the second relay coil 49 is identical with maintenance voltage, with induced-current, with the different relay of maintenance electric current, also is fine.In this case, relay that in case of necessity can be large according to induced-current at induced-current is set output voltage, is keeping the relay that electric current in case of necessity can be large according to the maintenance electric current to set output voltage.Like this, while driving relay, the setting value of the output voltage of the first DC power supply circuit 45 can have 2, and the combination of relay and induced-current or maintenance electric current just can be driven accurately.

Also have, the relay control device of the present embodiment does not show that the voltage detection department and the output voltage detecting circuit 47 that detect the first DC power supply circuit 45 arrange respectively in the drawings, also can be according to the detection voltage of this voltage detection department, the relay conducting is prohibited or is disengaged.As long as voltage detection department is detected the output voltage of the first DC power supply circuit 45, when the first DC power supply circuit 45 as shown in Fig. 3,6,7 has output voltage, just can judge that the output voltage of the first DC power supply circuit 45, whether as the voltage more than the induced-current that can supply with relay coil, can drive relay within the shortest time.Voltage detection department consists of resistor voltage divider circuit, as long as the built-in A/D converter of input micro computer, micro computer just can judge whether the setting voltage of the first DC power supply circuit 45 has output, and the fault of the first DC power supply circuit 45 also just can be discovered in an early phase.

Also have, utilize the temperature detecting part 84 shown in Fig. 5, just can infer the temperature of the second circuit board 82 that relay is housed, the resistance value of relay coil also just can be inferred, and by control part 50, just can be adjusted the output voltage of the first DC power supply circuit 45.Because the temperature difference can cause resistance variations, if the certain words of supply electric current of guard relay coil, the output voltage of the first DC power supply circuit 45 just is necessary to be adjusted, utilize temperature detecting part can supply with necessary minimum current, power consumption when like this, relay coil is switched on also just can minimize.

Also have, as the electric cooker of the present embodiment cooking machine, include above-mentioned relay control device, because relay can use for a long time, provide the cooking machine that a kind of product life is very long.

In addition, in the present embodiment, the heater of take describes as load, family's roast machine of toast bread for example, and in addition, the motor that raw material are stirred also can be used as load, and this motor is controlled also and is fine with the switching of relay.

According to upper type, about relay control device of the present invention, relay coil being carried out to the output voltage of the power circuit (the first DC power supply circuit) of electric current supply can be set by control part, control part carries out the output voltage of the first DC power supply circuit of electric current supply according to the ON time of relay to relay coil, from the voltage that can supply with more than faradic induced voltage, to the voltage that can supply with more than the maintenance voltage that keeps electric current, switched.Like this, can not be subject to the first dc source and form component deteriorated impact all the year round, can guarantee miniaturization and long-term use of component.In addition, cooking machine of the present invention is because relay can use for a long time, therefore can provide the cooking machine that a kind of life of product is very long, be all also of great use for take heater etc. for load the relay control device of being controlled with relay and the cooking machine that includes relay control device.

Claims (10)

1. a relay control device is characterized in that comprising:

AC power;

Load;

Make the current path conducting of above-mentioned load and above-mentioned AC power or the relay of disconnection;

Above-mentioned AC power is converted to the first DC power supply circuit of dc source;

The output voltage of above-mentioned the first DC power supply circuit is converted to than the output voltage of the first DC power supply circuit the second DC power supply circuit of low-voltage more; With

Carry out electric power by the second DC power supply circuit and supply with the also conducting of control relay and the control part of disconnection,

Above-mentioned the first DC power supply circuit has a plurality of output voltages, the driving electric power of above-mentioned relay is supplied with by the first DC power supply circuit according to the control signal of control part, above-mentioned control part is set as the output voltage of the first DC power supply circuit producing the magnitude of voltage more than the faradic induced voltage of relay when above-mentioned relay conducting, start to the stipulated time from the relay conducting, the output voltage of the first DC power supply circuit is set as producing the magnitude of voltage more than the maintenance voltage that relay keeps electric current.

2. relay control device as claimed in claim 1, it is characterized in that: when control part disconnects at relay, the output voltage of the first DC power supply circuit is set as than supplying with the voltage that faradic induced voltage is lower, and, before the relay conducting, the output voltage of the first above-mentioned DC power supply circuit is set as to the magnitude of voltage more than induced voltage.

3. relay control device as claimed in claim 2, is characterized in that: when control part disconnects at relay, the output voltage of the first DC power supply circuit is set as to the lower voltage of maintenance voltage that keeps electric current than supplying with.

4. relay control device as claimed in claim 1, it is characterized in that: the voltage detection department that also comprises the output voltage that detects the first DC power supply circuit, control part is when the relay conducting, the voltage that above-mentioned voltage detection department detects is when the induced voltage of above-mentioned relay is following, and control relay does not start conducting.

5. relay control device as claimed in claim 1 characterized by further comprising:

Be used for occurring the no-voltage synchronizing signal generating unit of the no-voltage synchronizing signal of AC power;

Be used for measuring the timer of above-mentioned no-voltage synchronizing signal generating unit output time; With

The timing setting section be used for to being set to the period of relay conducting or disconnection from no-voltage synchronizing signal generating unit output signal,

The output of the period that control part is set according to above-mentioned timing setting section and above-mentioned timing section carrys out conducting and the disconnection of control relay, and above-mentioned timing setting section also carries out the rotation change by the above-mentioned period according to the phase place of AC power positive and negative.

6. relay control device as claimed in claim 1 characterized by further comprising: a plurality of loads and a plurality of relays that the current path of above-mentioned a plurality of loads and AC power carried out respectively to conducting or disconnection,

Control part is in above-mentioned a plurality of relays during a conducting, no matter other relay is in conducting state or off-state, the output voltage of the first DC power supply circuit will be set as supplying with the above magnitude of voltage of the faradic induced voltage of above-mentioned relay, then, after stipulated time, the output voltage of the first DC power supply circuit will be set as supplying with the above magnitude of voltage of maintenance voltage that above-mentioned relay keeps electric current.

7. relay control device as claimed in claim 6, characterized by further comprising the different plural relay of induced-current,

Control part, when the relay conducting, in above-mentioned different induced-currents, can be supplied with the output voltage that maximum faradic induced voltage is set to the first DC power supply circuit.

8. relay control device as claimed in claim 7, characterized by further comprising and keep the different plural relay of electric current,

Control part is when the relay conducting, in above-mentioned different induced-current, can supply with the output voltage that maximum faradic induced voltage is set to the first DC power supply circuit, after relay is conducting to the stipulated time, above-mentioned different the maintenance in electric current,, the maintenance voltage that can supply with maximum maintenance electric current is set to the output voltage of the first DC power supply circuit.

9. relay control device as claimed in claim 1 is characterized in that: comprise the temperature detecting part that detects near temperature relay, control part will, according to the output of said temperature test section, change the output voltage of the first DC power supply circuit.

10. a cooking machine, is characterized in that: comprise the relay control device described in any one in claim 1～9.

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