CN114430264A - Slow start control circuit and method and household appliance - Google Patents
Slow start control circuit and method and household appliance Download PDFInfo
- Publication number
- CN114430264A CN114430264A CN202111666462.3A CN202111666462A CN114430264A CN 114430264 A CN114430264 A CN 114430264A CN 202111666462 A CN202111666462 A CN 202111666462A CN 114430264 A CN114430264 A CN 114430264A
- Authority
- CN
- China
- Prior art keywords
- power supply
- zero
- signal
- alternating current
- resistor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K17/00—Electronic switching or gating, i.e. not by contact-making and –breaking
- H03K17/13—Modifications for switching at zero crossing
- H03K17/136—Modifications for switching at zero crossing in thyristor switches
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B19/00—Programme-control systems
- G05B19/02—Programme-control systems electric
- G05B19/04—Programme control other than numerical control, i.e. in sequence controllers or logic controllers
- G05B19/042—Programme control other than numerical control, i.e. in sequence controllers or logic controllers using digital processors
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H9/00—Details of switching devices, not covered by groups H01H1/00 - H01H7/00
- H01H9/54—Circuit arrangements not adapted to a particular application of the switching device and for which no provision exists elsewhere
- H01H9/56—Circuit arrangements not adapted to a particular application of the switching device and for which no provision exists elsewhere for ensuring operation of the switch at a predetermined point in the ac cycle
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03K—PULSE TECHNIQUE
- H03K2217/00—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00
- H03K2217/0009—AC switches, i.e. delivering AC power to a load
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Automation & Control Theory (AREA)
- Power Engineering (AREA)
- Rectifiers (AREA)
Abstract
The invention discloses a slow start control circuit, a method and a household appliance, wherein the circuit comprises a zero-crossing detection unit, detects direct-current voltage output from a rectifier bridge after the household appliance is electrified, and sends a first signal to an MCU (microprogrammed control Unit) when the direct-current voltage drops to a detection threshold value, and sends a second signal to the MCU when the direct-current voltage rises to the detection threshold value; the MCU is used for determining the zero-crossing time and the frequency of the alternating current power supply according to the first signal and the second signal and sending a slow start control signal to the slow start unit according to the zero-crossing time and the frequency of the alternating current power supply when receiving an external start instruction of the household appliance; and the slow starting unit is used for controlling a power switch of the household appliance according to the slow starting control signal so as to start the household appliance, thereby realizing the self-adaption of the frequency of the power grid during zero-crossing detection and improving the starting reliability of the household appliance after the zero-crossing point is accurately detected.
Description
Technical Field
The application relates to the technical field of household appliances, in particular to a slow start control circuit and method and a household appliance.
Background
Among the domestic appliance, all there is very big electric current in the twinkling of an eye opening switch or power-on, this is very big harm to some electronic components on the household electrical appliances, for example the motor of air conditioner, the inside stove lamp of oven, the lamp pearl of lamp area etc. and the heavy current of power-on or opening switch's a twinkling of an eye production is very fatal damage to these electronic components, can cause electronic components to damage, influences the normal use of household electrical appliances, shortens the life of household electrical appliances.
As the civil power grid of China is alternating current 220V, 50HZTherefore, the zero point of the alternating current input electricity can be collected based on the characteristic of the frequency of the alternating current, then the zero point is converted into an electric signal at the moment, the electric signal is transmitted to the input pin of the MCU, the MCU can obtain the zero point moment of the alternating current input electricity, the circuit switch is controlled at the moment, the electronic components which are easy to damage are started, the alternating current input voltage at the moment is minimum, the instantaneous input current of the switch is reduced to a great extent, and the purpose of protecting the electronic components is achieved. However, if the frequency of the power grid changes, the slow start process is affected, which may damage the electrical equipment and cause poor slow start effect.
Therefore, how to provide a slow start control circuit capable of improving the start reliability of the household appliance is a technical problem to be solved at present.
Disclosure of Invention
The invention discloses a slow start control circuit, which is used for solving the technical problem of low reliability in starting household appliances in the prior art.
The circuit comprises a zero-crossing detection unit, an MCU and a slow start unit, wherein,
the zero-crossing detection unit detects the direct-current voltage output from the rectifier bridge after the household appliance is electrified, and sends a first signal to the MCU when the direct-current voltage is reduced to a detection threshold value, and sends a second signal to the MCU when the direct-current voltage is increased to the detection threshold value;
the MCU is used for determining the zero-crossing time and the frequency of the alternating current power supply according to the first signal and the second signal and sending a slow start control signal to the slow start unit according to the zero-crossing time and the frequency of the alternating current power supply when receiving an external start instruction of the household appliance;
and the slow starting unit is used for controlling a power switch of the household appliance according to the slow starting control signal so as to start the household appliance.
In some embodiments of the present application, the MCU is specifically configured to:
acquiring a first signal, a first second signal and a second first signal which are continuously received;
determining the time difference deltat between the first signal and the zero-crossing moment of the alternating current power supply:
Δt＝(t2-t1)/2；
determining the zero-crossing time a of the alternating current power supply:
a＝t1+Δt；
determining the frequency f of the alternating current power supply:
f＝1/(t3-t1)*2；
where t1 is the time when the first signal is detected, t2 is the time when the first second signal is detected, and t3 is the time when the second first signal is detected.
In some embodiments of the present application, the MCU is further specifically configured to:
determining the zero-crossing time of each alternating current power supply with a preset period number after the zero-crossing time of the first alternating current power supply is determined according to the zero-crossing time of the first alternating current power supply and the frequency of the alternating current power supply detected after an external starting instruction of the household appliance is received;
determining each starting time interval according to the zero-crossing time of each alternating current power supply within the preset period number and the preset forward time interval;
after detecting the zero-crossing moment of the alternating current power supply every time, sending the slow starting control signal to the slow starting unit through each starting time interval, and controlling a power switch of the household appliance to be in a continuous opening state when a preset period number is reached;
wherein, the power switch of the household appliance is turned on when receiving the slow start control signal and is turned off when the current direction of the AC power supply changes, and each turn-on time interval is delta TnT-n Δ a, where the period T is 1/f, Δ a is a preset advance time interval, n represents the zero-crossing time of the nth ac power supply within the preset period number, n is 1, 2, 3 … s, and s is the preset period number.
In some embodiments of the present application, the zero crossing detection unit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first diode, an optocoupler, a first triode, a first capacitor, and a second capacitor, wherein,
the first end of the second resistor is connected with the first output end of the rectifier bridge, the first end of the fifth resistor is connected with the second output end of the rectifier bridge, the second end of the second resistor and the second end of the fifth resistor are connected with the cathode of the first diode in a shared mode, the first end of the fifth resistor is connected with the anode of the first diode, the cathode of the first diode is connected with the anode of the light-emitting diode of the optical coupler, the anode of the first diode is connected with the cathode of the light-emitting diode of the optical coupler, the collector of the phototriode of the optical coupler is connected with a first direct current power supply, the emitter of the phototriode of the optical coupler is connected with the first end of the sixth resistor, the first end of the second capacitor and the first end of the fourth resistor, the second end of the fourth resistor is connected with the base of the first triode, the collector of the first triode is connected with the first end of the first resistor and the first end of the third resistor, and the second end of the first resistor is connected with the second direct current power supply, the second end of the third resistor and the first end of the first capacitor are connected to the zero-crossing detection input end of the MCU, the second end of the sixth resistor and the second end of the second capacitor, and the emitter of the first triode and the second end of the first capacitor are grounded.
In some embodiments of the present application, the soft start unit includes a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a thyristor serving as a power switch of the household appliance, an optocoupler thyristor, and a third capacitor, wherein,
the connector of domestic appliance is connected to the first end of seventh resistance, the second end of seventh resistance and the first end of ninth resistance connect in the second end of silicon controlled rectifier altogether, the first end of silicon controlled rectifier, alternating current power supply is connected to the first end of eighth resistance and the first end of third electric capacity, the third end of silicon controlled rectifier and the second end of eighth resistance connect in the first output of opto-coupler silicon controlled rectifier altogether, the second end of ninth resistance and the second end of third electric capacity connect in the first end of tenth resistance altogether, the second output of opto-coupler silicon controlled rectifier is connected to the second end of tenth resistance, the first input of opto-coupler silicon controlled rectifier is connected through eleventh resistance MCU's slow start control end, the second input ground connection of opto-coupler silicon controlled rectifier.
Correspondingly, the invention also provides a slow start control method, which comprises the following steps:
detecting a direct current voltage output from a rectifier bridge after the household appliance is powered on, triggering a first signal when the direct current voltage is reduced to a detection threshold value, and triggering a second signal when the direct current voltage is increased to the detection threshold value;
determining the zero crossing time and the frequency of the alternating current power supply according to the first signal and the second signal;
when an external starting instruction of the household appliance is received, a slow starting control signal is generated according to the zero-crossing time of the alternating current power supply and the frequency of the alternating current power supply, and a power switch of the household appliance is controlled according to the slow starting control signal so as to start the household appliance.
In some embodiments of the present application, the determining the zero-crossing time of the ac power and the frequency of the ac power according to the first signal and the second signal specifically includes:
acquiring a first signal, a first second signal and a second first signal which are continuously received;
determining a time difference Δ t between the first signal and a zero-crossing instant of the alternating current power supply:
Δt＝(t2-t1)/2；
determining the zero-crossing time a of the alternating current power supply:
a＝t1+Δt；
determining the frequency f of the alternating current power supply:
f＝1/(t3-t1)*2；
where t1 is the time when the first signal is detected, t2 is the time when the first second signal is detected, and t3 is the time when the second first signal is detected.
In some embodiments of the present application, a slow start control signal is generated according to an ac power supply zero crossing time and an ac power supply frequency, and a power switch of a household appliance is controlled according to the slow start control signal to start the household appliance, specifically:
determining the zero-crossing time of each alternating current power supply with a preset period number after the zero-crossing time of the first alternating current power supply is determined according to the zero-crossing time of the first alternating current power supply and the frequency of the alternating current power supply detected after an external starting instruction of the household appliance is received;
determining each starting time interval according to the zero-crossing time of each alternating current power supply within the preset period number and the preset forward time interval;
after detecting the zero-crossing moment of the alternating current power supply every time, sending the slow starting control signal to the slow starting unit through each starting time interval, and controlling a power switch of the household appliance to be in a continuous opening state when a preset period number is reached;
wherein, the power switch of the household appliance is turned on when receiving the slow start control signal and is turned off when the current direction of the AC power supply changes, and each turn-on time interval is delta TnT-n Δ a, where the period T is 1/f, Δ a is a preset advance time interval, n represents the zero-crossing time of the nth ac power supply within the preset period number, n is 1, 2, 3 … s, and s is the preset period number.
Correspondingly, the invention also provides a household appliance which comprises the slow start control circuit.
By applying the technical scheme, the slow start control circuit comprises a zero-crossing detection unit, an MCU (microprogrammed control unit) and a slow start unit, wherein the zero-crossing detection unit detects the direct-current voltage output from the rectifier bridge after the household appliance is electrified, and sends a first signal to the MCU when the direct-current voltage drops to a detection threshold value, and sends a second signal to the MCU when the direct-current voltage rises to the detection threshold value; the MCU is used for determining the zero-crossing time and the frequency of the alternating current power supply according to the first signal and the second signal and sending a slow start control signal to the slow start unit according to the zero-crossing time and the frequency of the alternating current power supply when receiving an external start instruction of the household appliance; and the slow starting unit is used for controlling a power switch of the household appliance according to the slow starting control signal so as to start the household appliance, thereby realizing the self-adaption of the frequency of the power grid during zero-crossing detection and improving the starting reliability of the household appliance after the zero-crossing point is accurately detected.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic structural diagram illustrating a slow start control circuit according to an embodiment of the present invention;
FIG. 2 is a schematic diagram illustrating the control principle of zero-crossing detection in the embodiment of the present invention;
FIG. 3 is a schematic diagram illustrating a slow start control principle according to an embodiment of the present invention;
FIG. 4 is a schematic diagram illustrating a structure of a zero-crossing detection unit according to an embodiment of the present invention;
FIG. 5 is a schematic structural diagram illustrating a slow start unit according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of a slow start control circuit according to another embodiment of the present invention;
fig. 7 shows a schematic structural diagram of a slow start control method according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The embodiment of the present application provides a slow start control circuit, as shown in fig. 1, the circuit includes a zero-crossing detection unit 100, an MCU200, and a slow start unit 300, wherein,
the zero-crossing detection unit 100 detects a direct-current voltage output from the rectifier bridge after the household appliance is powered on, and transmits a first signal to the MCU200 when the direct-current voltage drops to a detection threshold value, and transmits a second signal to the MCU200 when the direct-current voltage rises to the detection threshold value;
the MCU200 is used for determining the zero-crossing moment and the frequency of the alternating current power supply according to the first signal and the second signal, and sending a slow start control signal to the slow start unit 300 according to the zero-crossing moment and the frequency of the alternating current power supply when receiving an external start instruction of the household appliance;
and a slow start unit 300 for turning on a power switch of the home appliance according to the slow start control signal to start the home appliance.
In the present embodiment, the household appliances may include, but are not limited to, an air conditioner, a refrigerator, a washing machine, an oven, and the like. The rectifier bridge converts the ac power into the dc power, and after the household appliance is powered on, the zero-cross detection unit 100 detects the dc voltage output from the rectifier bridge, transmits a first signal to the MCU200 when the dc voltage drops to a detection threshold, and transmits a second signal to the MCU200 when the dc voltage rises to the detection threshold.
Optionally, the first signal is at a high level and the second signal is at a low level, or the first signal is at a low level and the second signal is at a high level.
The MCU200 can determine the zero-crossing time and the frequency of the alternating current power supply according to the first signal and the second signal sent by the zero-crossing detection unit 100, the external starting instruction can be sent by a user or triggered when the starting condition is met, when the external starting instruction of the household appliance is received, the MCU200 sends a slow starting control signal to the slow starting unit 300 according to the zero-crossing time and the frequency of the alternating current power supply, so that the slow starting unit 300 opens a power switch of the household appliance according to the slow starting control signal to start the household appliance, the frequency of the self-adaptive power grid during zero-crossing detection is realized, and the slow starting of the household appliance is reliably carried out after the zero-crossing point is accurately detected.
In order to reliably determine the ac power supply zero crossing time and the ac power supply frequency, in some embodiments of the present application, the MCU is specifically configured to:
acquiring a first signal, a first second signal and a second first signal which are continuously received;
determining the time difference deltat between the first signal and the zero crossing moment of the alternating current power supply:
Δt＝(t2-t1)/2；
determining the zero-crossing time a of the alternating current power supply:
a＝t1+Δt；
determining the frequency f of the alternating current power supply:
f＝1/(t3-t1)*2；
where t1 is the time when the first signal is detected, t2 is the time when the first second signal is detected, and t3 is the time when the second first signal is detected.
In this embodiment, fig. 2 is a schematic diagram of a zero-crossing detection control principle, and fig. 2 also shows a rectified voltage waveform.
If the detection threshold is u1, when the rectified dc voltage drops to u1, the zero-crossing detection unit is triggered to operate, and at this time, the zero-crossing detection unit outputs a high level (or a low level) (i.e., a first signal) to the MCU pin, and triggers a timer inside the MCU to start, and records the zero-crossing time t1 at this time.
Since the rectified voltage period is 1/2 before rectification, when the next voltage threshold comes (i.e. the dc voltage rises to u1), the zero-crossing detection unit is also triggered, and at this time, the zero-crossing detection unit outputs a low level (or a high level) (i.e. the first second signal) to the MCU pin, triggers the start of the timer inside the MCU, and records the zero-crossing time t2 at this time. The time difference Δ t between the first signal and the zero-crossing moment of the alternating current power supply can be calculated inside the MCU:
Δt＝(t2-t1)/2；
therefore, the zero-crossing time a of the alternating current power supply can be calculated:
a＝t1+Δt；
when the next zero-crossing point comes (i.e., the second first signal is detected), the time t3 at this time can also be read, and the ac power frequency f can be calculated:
f＝1/(t3-t1)*2
for reliable start-up of the household appliance, in some embodiments of the present application, the MCU is further specifically configured to:
determining the zero-crossing time of each alternating current power supply with a preset period number after the zero-crossing time of the first alternating current power supply is determined according to the zero-crossing time of the first alternating current power supply and the frequency of the alternating current power supply detected after an external starting instruction of the household appliance is received;
determining each starting time interval according to the zero-crossing time of each alternating current power supply within the preset period number and the preset forward time interval;
after detecting the zero-crossing moment of the alternating current power supply each time, sending a slow start control signal to a slow start unit through each start time interval, and controlling a power switch of the household appliance to be in a continuous opening state when a preset period number is reached;
wherein each opening time interval is delta TnT-n Δ a, where the period T is 1/f, Δ a is a preset advance time interval, n represents the zero-crossing time of the nth ac power supply within the preset period number, n is 1, 2, 3 … s, and s is the preset period number.
In this embodiment, after receiving an external start instruction of the home appliance, the slow start of the home appliance may be completed by a preset cycle number of the ac power supply, and specifically, after receiving the external start instruction, a first ac power supply zero crossing time is detected, and a cycle of the ac power supply may be determined according to an ac power supply frequency, so that each ac power supply zero crossing time after the first ac power supply zero crossing time may be determined according to the cycle of the ac power supply, and each ac power supply zero crossing time is within the preset cycle number.
Then according to the preset period numberEach alternating current power supply zero crossing moment and a preset forward time interval determine each starting time interval, and each starting time interval is delta TnT-n Δ a, where the period T is 1/f, Δ a is a preset advance time interval, n represents the zero-crossing time of the nth ac power supply within the preset period number, n is 1, 2, 3 … s, and s is the preset period number.
The power switch of the household appliance is turned on when receiving the slow start control signal and turned off when the current direction of the alternating current power supply changes, the slow start control signal is sent to the slow start unit through each start time interval after the zero-crossing moment of the alternating current power supply is detected every time, the power switch of the household appliance is turned on intermittently, and the power switch of the household appliance is controlled to be in a continuous on state when the preset period number is reached, so that the household appliance is started.
For example, as shown in fig. 3, after receiving an external start command of the household appliance, the MCU detects that the dc voltage drops to a detection threshold at a time a0, determines the first ac power zero-crossing time T0 according to the sum of a0 and Δ T, and determines the subsequent times T1, T2 and T3 … … according to T0 and the ac power frequency f.
(1) Before the next AC power supply zero-crossing time T1 comes, the power switch is turned on at a1, and the turn-on time interval Delta T is different between T0 and a11＝T-Δa；
(2) Before the next AC power supply zero-crossing time T2 comes, the power switch is turned on at a2, and the T1 time and the a2 time are different by a turn-on time interval delta T2＝T-2Δa；
(3) Before the next AC power supply zero-crossing time T3 comes, the power switch is turned on at a3, and the T2 time and the a3 time are different by a turn-on time interval delta T3And circulating in the way, and controlling a power switch of the household appliance to be in a continuous opening state by the MCU after the preset period number is reached, so as to finish the slow start of the household appliance.
In order to improve the reliability of the zero-crossing detection unit, in some embodiments of the present application, as shown in fig. 4, the zero-crossing detection unit includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first diode V2, an optical coupler B1, a first transistor V1, a first capacitor C1, and a second capacitor C2, wherein,
a first end of a second resistor R2 is connected with a first output end of a rectifier bridge VC1, a first end of a fifth resistor R5 is connected with a second output end of a rectifier bridge VC1, a second end of the second resistor R2 and a second end of a fifth resistor R5 are commonly connected with a cathode of a first diode V2, a first end of a fifth resistor R5 is connected with an anode of a first diode V2, a cathode of a first diode V2 is connected with an anode of a light emitting diode of an optocoupler B1, an anode of a first diode V2 is connected with a cathode of a light emitting diode of an optocoupler B1, a collector of a phototransistor of the optocoupler B1 is connected with a first direct current power supply VCC1, an emitter of a phototransistor of an optocoupler B1 is connected with a first end of a sixth resistor R6, a first end of a second capacitor C2 and a first end of a fourth resistor R4, a second end of a fourth resistor R4 is connected with a base of a first triode V1, a collector of a first resistor V1 is connected with a first end of the first resistor R1 and a first end of the third resistor R3, the second end of the first resistor R1 is connected to the second dc power supply VCC2, the second end of the third resistor R3 and the first end of the first capacitor C1 are connected to the ZERO-cross detection input terminal ZERO _ TEST of the MCU (i.e., the input GPIO port of the MCU), the second end of the sixth resistor R6 and the second end of the second capacitor C2, and the emitter of the first transistor V1 and the second end of the first capacitor C1 are both grounded.
In order to improve the reliability of the slow start unit, in some embodiments of the present application, as shown in fig. 5, the slow start unit includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a thyristor V3 as a power switch of the household appliance, an optocoupler thyristor N1, and a third capacitor C3, wherein,
the first end of the seventh resistor R7 is connected with a connecting port (L-OUT of X1) of the household appliance, the second end of the seventh resistor R7 and the first end of the ninth resistor R9 are connected to the second end of the thyristor V3, the first ends of the thyristor V3, the eighth resistor R8 and the third capacitor C3 are connected with an alternating current power supply L-IN, the third end of the thyristor V3 and the second end of the eighth resistor R8 are connected to the first output end of the optocoupler N1, the second end of the ninth resistor R9 and the second end of the third capacitor C3 are connected to the first end of the tenth resistor R10, the second end of the tenth resistor R10 is connected to the second output end of the optocoupler N1, the first input end of the thyristor optocoupler N1 is connected to the ROL (GPIO port of the single chip microcomputer) of the MCU through the eleventh resistor R11, and the second input end of the thyristor N1 is grounded.
In this embodiment, the thyristor V3 is a bidirectional thyristor, the slow start unit uses the thyristor V3 as a power switch, and the thyristor V3 cannot be turned off after being turned on due to the electronic characteristic of the thyristor V3 unless the current direction is changed to turn off the thyristor V3. The characteristics of the optocoupler thyristor N1 are similar to the characteristics of the thyristor V3.
Optionally, the thyristor V3 can be replaced by a relay to realize the function of a circuit switch.
Fig. 6 shows a schematic structural diagram of a slow start control circuit according to another embodiment of the present invention, in which the slow start unit includes a thyristor and an optocoupler thyristor.
By applying the technical scheme, the slow start control circuit comprises a zero-crossing detection unit, an MCU (microprogrammed control unit) and a slow start unit, wherein the zero-crossing detection unit detects the direct-current voltage output from the rectifier bridge after the household appliance is electrified, and sends a first signal to the MCU when the direct-current voltage drops to a detection threshold value, and sends a second signal to the MCU when the direct-current voltage rises to the detection threshold value; the MCU is used for determining the zero-crossing time and the frequency of the alternating current power supply according to the first signal and the second signal and sending a slow start control signal to the slow start unit according to the zero-crossing time and the frequency of the alternating current power supply when receiving an external start instruction of the household appliance; and the slow starting unit is used for controlling a power switch of the household appliance according to the slow starting control signal so as to start the household appliance, thereby realizing the self-adaption of the frequency of the power grid during zero-crossing detection and improving the starting reliability of the household appliance after the zero-crossing point is accurately detected.
The embodiment of the application further provides a slow start control method, as shown in fig. 7, which includes the following steps:
step S101, detecting direct current voltage output from a rectifier bridge after the household appliance is electrified, triggering a first signal when the direct current voltage is reduced to a detection threshold value, and triggering a second signal when the direct current voltage is increased to the detection threshold value;
step S102, determining the zero crossing time and the alternating current power supply frequency of the alternating current power supply according to the first signal and the second signal;
and step S103, when receiving an external starting instruction of the household appliance, generating a slow starting control signal according to the zero-crossing time of the alternating current power supply and the frequency of the alternating current power supply, and controlling a power switch of the household appliance according to the slow starting control signal so as to start the household appliance.
In order to reliably determine the ac power supply zero crossing time and the ac power supply frequency, in some embodiments of the present application, the ac power supply zero crossing time and the ac power supply frequency are determined according to the first signal and the second signal, specifically:
acquiring a first signal, a first second signal and a second first signal which are continuously received;
determining a time difference Δ t between the first signal and a zero-crossing instant of the alternating current power supply:
Δt＝(t2-t1)/2；
determining the zero-crossing time a of the alternating current power supply:
a＝t1+Δt；
determining the frequency f of the alternating current power supply:
f＝1/(t3-t1)*2；
where t1 is the time when the first signal is detected, t2 is the time when the first second signal is detected, and t3 is the time when the second first signal is detected.
In order to reliably start the household appliance, in some embodiments of the present application, a slow start control signal is generated according to a zero crossing time of an ac power supply and a frequency of the ac power supply, and a power switch of the household appliance is controlled according to the slow start control signal to start the household appliance, specifically:
determining the zero-crossing time of each alternating current power supply with a preset period number after the zero-crossing time of the first alternating current power supply is determined according to the zero-crossing time of the first alternating current power supply and the frequency of the alternating current power supply detected after an external starting instruction of the household appliance is received;
determining each starting time interval according to the zero-crossing time of each alternating current power supply within the preset period number and the preset forward time interval;
after detecting the zero-crossing moment of the alternating current power supply each time, sending a slow start control signal to a slow start unit through each start time interval, and controlling a power switch of the household appliance to be in a continuous opening state when a preset period number is reached;
wherein, the power switch of the household appliance is turned on when receiving the slow start control signal and is turned off when the current direction of the AC power supply changes, and each turn-on time interval is delta TnT-n Δ a, where the period T is 1/f, Δ a is a preset advance time interval, n represents the zero-crossing time of the nth ac power supply within the preset period number, n is 1, 2, 3 … s, and s is the preset period number.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not necessarily depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.
Claims (9)
1. A slow start control circuit is characterized by comprising a zero-crossing detection unit, an MCU (microprogrammed control unit) and a slow start unit, wherein,
the zero-crossing detection unit detects the direct-current voltage output from the rectifier bridge after the household appliance is electrified, and sends a first signal to the MCU when the direct-current voltage is reduced to a detection threshold value, and sends a second signal to the MCU when the direct-current voltage is increased to the detection threshold value;
the MCU is used for determining the zero-crossing time and the frequency of the alternating current power supply according to the first signal and the second signal and sending a slow start control signal to the slow start unit according to the zero-crossing time and the frequency of the alternating current power supply when receiving an external start instruction of the household appliance;
and the slow starting unit is used for controlling a power switch of the household appliance according to the slow starting control signal so as to start the household appliance.
2. The circuit of claim 1, wherein the MCU is specifically configured to:
acquiring a first signal, a first second signal and a second first signal which are continuously received;
determining the time difference deltat between the first signal and the zero crossing moment of the alternating current power supply:
Δt＝(t2-t1)/2；
determining the zero-crossing time a of the alternating current power supply:
a＝t1+Δt；
determining the frequency f of the alternating current power supply:
f＝1/(t3-t1)*2；
where t1 is the time when the first signal is detected, t2 is the time when the first second signal is detected, and t3 is the time when the second first signal is detected.
3. The circuit of claim 2, wherein the MCU is further specifically configured to:
determining the zero-crossing time of each alternating current power supply with a preset period number after the zero-crossing time of the first alternating current power supply is determined according to the zero-crossing time of the first alternating current power supply and the frequency of the alternating current power supply detected after an external starting instruction of the household appliance is received;
determining each starting time interval according to the zero-crossing time of each alternating current power supply within the preset period number and the preset forward time interval;
after detecting the zero-crossing moment of the alternating current power supply every time, sending the slow starting control signal to the slow starting unit through each starting time interval, and controlling a power switch of the household appliance to be in a continuous opening state when a preset period number is reached;
wherein, the power switch of the household appliance is turned on when receiving the slow start control signal and is turned off when the current direction of the AC power supply changes, and each turn-on time interval is delta TnWhere the period T is 1/f, Δ a is a predetermined advance time interval, n is tableThe zero-crossing time of the nth alternating current power supply within the preset period number is shown, wherein n is 1, 2 and 3 … s, and s is the preset period number.
4. The circuit of claim 1, wherein the zero-crossing detection unit comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a first diode, an optocoupler, a first triode, a first capacitor, and a second capacitor, wherein,
the first end of the second resistor is connected with the first output end of the rectifier bridge, the first end of the fifth resistor is connected with the second output end of the rectifier bridge, the second end of the second resistor and the second end of the fifth resistor are connected with the cathode of the first diode in a shared mode, the first end of the fifth resistor is connected with the anode of the first diode, the cathode of the first diode is connected with the anode of the light-emitting diode of the optical coupler, the anode of the first diode is connected with the cathode of the light-emitting diode of the optical coupler, the collector of the phototriode of the optical coupler is connected with a first direct current power supply, the emitter of the phototriode of the optical coupler is connected with the first end of the sixth resistor, the first end of the second capacitor and the first end of the fourth resistor, the second end of the fourth resistor is connected with the base of the first triode, the collector of the first triode is connected with the first end of the first resistor and the first end of the third resistor, and the second end of the first resistor is connected with the second direct current power supply, the second end of the third resistor and the first end of the first capacitor are connected to the zero-crossing detection input end of the MCU, the second end of the sixth resistor and the second end of the second capacitor, and the emitter of the first triode and the second end of the first capacitor are grounded.
5. The circuit of claim 1, wherein the soft start unit comprises a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a thyristor functioning as a power switch of the household appliance, an optocoupler thyristor, and a third capacitor, wherein,
the connector of domestic appliance is connected to the first end of seventh resistance, the second end of seventh resistance and the first end of ninth resistance connect in the second end of silicon controlled rectifier altogether, the first end of silicon controlled rectifier, alternating current power supply is connected to the first end of eighth resistance and the first end of third electric capacity, the third end of silicon controlled rectifier and the second end of eighth resistance connect in the first output of opto-coupler silicon controlled rectifier altogether, the second end of ninth resistance and the second end of third electric capacity connect in the first end of tenth resistance altogether, the second output of opto-coupler silicon controlled rectifier is connected to the second end of tenth resistance, the first input of opto-coupler silicon controlled rectifier is connected through eleventh resistance MCU's slow start control end, the second input ground connection of opto-coupler silicon controlled rectifier.
6. A slow start control method is characterized by comprising the following steps:
detecting a direct current voltage output from a rectifier bridge after the household appliance is powered on, triggering a first signal when the direct current voltage is reduced to a detection threshold value, and triggering a second signal when the direct current voltage is increased to the detection threshold value;
determining the zero crossing time and the frequency of the alternating current power supply according to the first signal and the second signal;
when an external starting instruction of the household appliance is received, a slow starting control signal is generated according to the zero-crossing time of the alternating current power supply and the frequency of the alternating current power supply, and a power switch of the household appliance is controlled according to the slow starting control signal so as to start the household appliance.
7. The method according to claim 6, wherein the determining the ac power supply zero crossing time and the ac power supply frequency based on the first signal and the second signal comprises:
acquiring a first signal, a first second signal and a second first signal which are continuously received;
determining a time difference Δ t between the first signal and a zero-crossing instant of the alternating current power supply:
Δt＝(t2-t1)/2；
determining the zero-crossing time a of the alternating current power supply:
a＝t1+Δt；
determining the frequency f of the alternating current power supply:
f＝1/(t3-t1)*2；
where t1 is the time when the first signal is detected, t2 is the time when the first second signal is detected, and t3 is the time when the second first signal is detected.
8. The method according to claim 7, wherein a slow start control signal is generated according to the ac power supply zero crossing time and the ac power supply frequency, and a power switch of the household appliance is controlled according to the slow start control signal to start the household appliance, specifically:
determining the zero-crossing time of each alternating current power supply with a preset period number after the zero-crossing time of the first alternating current power supply is determined according to the zero-crossing time of the first alternating current power supply and the frequency of the alternating current power supply detected after an external starting instruction of the household appliance is received;
determining each starting time interval according to the zero-crossing time of each alternating current power supply within the preset period number and the preset forward time interval;
after detecting the zero-crossing moment of the alternating current power supply every time, sending the slow starting control signal to the slow starting unit through each starting time interval, and controlling a power switch of the household appliance to be in a continuous opening state when a preset period number is reached;
wherein, the power switch of the household appliance is turned on when receiving the slow start control signal and is turned off when the current direction of the AC power supply changes, and each turn-on time interval is delta TnT-n Δ a, where the period T is 1/f, Δ a is a preset advance time interval, n represents the zero-crossing time of the nth ac power supply within the preset period number, n is 1, 2, 3 … s, and s is the preset period number.
9. A household appliance comprising a slow start control circuit as claimed in any one of claims 1 to 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111666462.3A CN114430264A (en) | 2021-12-31 | 2021-12-31 | Slow start control circuit and method and household appliance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111666462.3A CN114430264A (en) | 2021-12-31 | 2021-12-31 | Slow start control circuit and method and household appliance |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114430264A true CN114430264A (en) | 2022-05-03 |
Family
ID=81310549
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111666462.3A Pending CN114430264A (en) | 2021-12-31 | 2021-12-31 | Slow start control circuit and method and household appliance |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114430264A (en) |
-
2021
- 2021-12-31 CN CN202111666462.3A patent/CN114430264A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109963393B (en) | Flash switch detection circuit | |
| CN110191549B (en) | LED (light emitting diode) accurate timing switch lamp and accurate timing drive circuit thereof | |
| CN109991535B (en) | Flash switch control system and input flash detection circuit thereof | |
| CN109963396A (en) | A kind of switch detection circuit | |
| CN105472815B (en) | LED illumination lamp and its control chip and the method for wherein carrying out color-temperature regulating control | |
| CN109963394A (en) | A kind of flash switch detection circuit and Intelligent lamp | |
| CN208112227U (en) | A kind of electric hair drier control circuit of high reliability | |
| CN211063817U (en) | Flash detection control device, electronic equipment comprising same and system | |
| CN104950772B (en) | A kind of dish-washing machine and its stand-by power consumption control device and method | |
| CN202794915U (en) | Isolation-type zero standby power consumption circuit | |
| US6236584B1 (en) | Automatic voltage conversion module | |
| EP4293888A1 (en) | Ac-side precharge isolation detection circuit and ac-side precharge circuit | |
| CN114430264A (en) | Slow start control circuit and method and household appliance | |
| CN110416009B (en) | Arc-free long-life relay switch circuit and controller | |
| CN207975006U (en) | driving circuit | |
| CN107437849B (en) | Local power network on-line switch modulation digital communication control system | |
| CN103314496B (en) | For run electric loading circuit arrangement, for triggering the control device of the drive motor of home appliances, home appliances and the method for running the electric loading in home appliances | |
| CN210129019U (en) | Flash switch control system and input flash detection circuit thereof | |
| CN215526395U (en) | Intelligent switch with zero-crossing detection function | |
| CN114019884A (en) | Household appliance power consumption control circuit and household appliance | |
| CN212905128U (en) | Zero-crossing detection circuit | |
| CN218767140U (en) | Test circuit for EMC voltage sag and short-time interruption test | |
| CN202649723U (en) | Novel self-start controller for use after power recovery of air conditioner | |
| CN219936044U (en) | Relay on-off detection circuit and household appliance | |
| CN215263706U (en) | Zero-crossing detection circuit, control circuit and household appliance |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information | ||
| CB02 | Change of applicant information |
Address after: No.1, Hisense Road, Nancun Town, Pingdu City, Qingdao City, Shandong Province 266700 Applicant after: Hisense Air Conditioning Co.,Ltd. Address before: No.1, Hisense Road, Nancun Town, Pingdu City, Qingdao City, Shandong Province 266700 Applicant before: HISENSE (SHANDONG) AIR-CONDITIONING Co.,Ltd. |