Disclosure of Invention
The present invention is directed to solving the problems described above. An object of the present invention is to provide a start-up control circuit of a dryer which improves a lifespan.
According to a first aspect of the present invention, a start control circuit of a dryer is connected with a start control relay of the dryer, the start control circuit of the dryer includes: the detection circuit of the strong door switch is used for outputting a first detection signal when the strong door switch of the clothes dryer is closed and outputting a second detection signal when the strong door switch of the clothes dryer is opened; a control signal generation circuit comprising: a first input for receiving the first detection signal or the second detection signal; a second input terminal for receiving a turn-on signal or a turn-off signal of a start switch of the dryer; a third input end, configured to receive a load control signal sent by a controller of the dryer, where the load control signal is used to instruct a load of the dryer to start working; and the output end is used for generating a starting control signal, and the starting control signal is used for controlling the starting control relay to be conducted so as to enable the load of the clothes dryer to start working.
Further, the strong gate switch detection circuit includes: the photoelectric coupler, the first diode, the filter capacitor, the first MOS tube and the first triode are connected in sequence; the input end of the photoelectric coupler is connected with the strong switch, the anode and the cathode of the first diode are respectively and correspondingly connected with the output end of the photoelectric coupler and the filter capacitor, the control end of the first MOS tube is connected with the anode of the filter capacitor, and the cathode of the filter capacitor is grounded.
Further, the first MOS transistor is an N-channel field effect transistor, and the first triode is an NPN-type triode; the control end of the first MOS tube is the grid electrode of the first MOS tube, the source electrode of the first MOS tube is grounded, the drain electrode of the first MOS tube is connected with a direct-current power supply and the base electrode of the first triode, the emitting electrode of the first triode is grounded, and the collecting electrode of the first triode is connected with the direct-current power supply and serves as the output end of the strong-current door switch detection circuit and is used for outputting the first detection signal or the second detection signal.
Furthermore, the collector of the first triode is connected with the direct current power supply through a first resistor, and the drain of the first MOS transistor is connected with the direct current power supply through a second resistor.
Further, the cathode of the first diode is connected with the anode of the filter capacitor through a third resistor; and the grid electrode of the first MOS tube is connected with the anode of the filter capacitor through a fourth resistor and is grounded through a fifth resistor.
Further, the control signal generation circuit includes: the second diode, the second triode, the third triode, the fourth triode, the fifth triode and the sixth triode; the base electrode of the second triode is connected with the second input end and the anode of the second diode, the cathode of the second diode is used as the first input end, and the first input end is also used for being connected with a strong switch detection end of the controller;
the output end of the second triode is connected with the bases of the third triode and the fourth triode, the output end of the fourth triode is connected with the base of the fifth triode, the sixth triode is grounded through the fifth triode, the base of the sixth triode is used as the third input end, and the output end of the sixth triode is connected with the control relay;
when the first input end receives the first detection signal and the second input end receives the conduction signal, the second triode, the third triode, the fourth triode, the fifth triode and the sixth triode are conducted, and the conducted third triode is used for stabilizing the base voltage of the second triode.
Further, the second diode is a schottky diode; the second triode is an NPN triode, an emitting electrode of the second triode is grounded, and a collecting electrode of the second triode is used as an output end.
Furthermore, the third triode and the fourth triode are PNP type triodes, the collector of the third triode is grounded, and the emitter of the third triode is connected with a direct current power supply; and the emitter of the fourth triode is connected with the direct-current power supply, the collector of the fourth triode is connected with the base of the fifth triode through a sixth resistor, and the base of the fifth triode is grounded through a seventh resistor.
Further, the fifth triode and the sixth triode are NPN triodes, an emitter of the fifth triode is grounded, a collector of the fifth triode is connected with an emitter of the sixth triode, a collector of the sixth triode is connected with the control end of the start control relay, and a base of the sixth triode is connected with the collector of the fifth triode through an eighth resistor.
Furthermore, the collector of the fourth triode is grounded through a third diode and a ninth resistor which are connected in series; the cathode of the third diode is also used for connecting a self-locking state detection end of a controller of the clothes dryer; or/and, the strong door switch is closed when a tub door of the dryer is closed and is opened when the tub door is opened.
The embodiment of the invention replaces a relay with the strong switch detection circuit and the control signal generation circuit to start and control the clothes dryer, and has the advantages of low circuit price, long service life and obvious advantages for batch products.
Other characteristic features and advantages of the invention will become apparent from the following description of exemplary embodiments, which is to be read in connection with the accompanying drawings.
The first embodiment is as follows:
as shown in fig. 1, a starting control circuit of a clothes dryer according to an embodiment of the present invention is configured to be connected to a starting control relay of the clothes dryer, and includes:
an electric door switch detection circuit 110 for outputting a first detection signal when an electric door switch of the dryer is turned on and outputting a second detection signal when the electric door switch of the dryer is turned off; wherein the strong door switch is closed when a tub door of the dryer is closed and is open when the tub door is open;
the control signal generation circuit 120 includes: a first input for receiving the first detection signal or the second detection signal; a second input terminal for receiving a turn-on signal or a turn-off signal of a start switch of the dryer; a third input end, configured to receive a load control signal sent by a controller of the dryer, where the load control signal is used to instruct a load of the dryer to start working; and the output end is used for generating a starting control signal when the first input end receives the first detection signal, the second input end receives the conduction signal and the third input end receives the load control signal, and the starting control signal is used for controlling the starting control relay to be conducted so as to enable the load of the clothes dryer to start working.
Specifically, the strong-door switch detection circuit includes: the photoelectric coupler IC1, the first diode D2, the filter capacitor C2, the first MOS tube MOS1 and the first triode NR1 are connected in sequence; the input end of the photoelectric coupler IC1 is connected with the strong switch, the anode and the cathode of the first diode D2 are respectively and correspondingly connected with the output end of the photoelectric coupler IC1 and the filter capacitor C2, the control end of the first MOS tube MOS1 is connected with the anode of the filter capacitor C2, and the cathode of the filter capacitor C2 is grounded.
The first MOS transistor MOS1 is an N-channel field effect transistor, and the first triode NR1 is an NPN type triode; the control end of the first MOS transistor MOS1 is the gate of the first MOS transistor, the source of the first MOS transistor MOS1 is grounded, the drain of the first MOS transistor MOS1 is connected to a dc power supply and the base of the first transistor NR1, the emitter of the first transistor NR1 is grounded, and the collector of the first transistor NR1 is connected to the dc power supply and serves as the output end of the strong gate switch detection circuit, so as to output the first detection signal or the second detection signal.
The collector of the first triode NR1 is connected with the DC power supply through a first resistor R1, and the drain of the first MOS transistor MOS1 is connected with the DC power supply through a second resistor R2.
The cathode of the first diode D2 is connected with the anode of the filter capacitor C2 through a third resistor R10; the gate of the first MOS transistor MOS1 is connected to the anode of the filter capacitor C2 through a fourth resistor R6 and is grounded through a fifth resistor R9.
The control signal generation circuit includes: a second diode D4, a second triode N3, a third triode P1, a fourth triode P2, a fifth triode N2, and a sixth triode N1; the base of the second triode N3 is connected to the second input terminal and the anode of the second diode D4, the cathode of the second diode D4 is used as the first input terminal, and the first input terminal is further used for connecting a strong gate switch detection terminal of the controller.
The output of second triode N3 is connected the base of third triode P1 and fourth triode P2, the output of fourth triode P2 is connected the base of fifth triode N2, sixth triode N1 passes through fifth triode N2 ground connection, the base of sixth triode N1 is as the third input, the output of sixth triode N1 is connected the control relay.
When the first input terminal receives the first detection signal and the second input terminal receives the conducting signal, the second transistor N3, the third transistor P1, the fourth transistor P2, the fifth transistor N2 and the sixth transistor N1 are turned on, and the turned on third transistor P1 is used for stabilizing the base voltage of the second transistor N3.
The second diode D4 is a schottky diode; the second triode N3 is an NPN type triode, the emitter of the second triode N3 is grounded, and the collector of the second triode N3 serves as an output terminal.
The third triode P1 and the fourth triode P2 are PNP type triodes, the collector of the third triode P1 is grounded, and the emitter of the third triode P1 is connected with a direct current power supply; an emitter of the fourth transistor P2 is connected to the dc power supply, a collector of the fourth transistor P2 is connected to a base of the fifth transistor N2 through a sixth resistor R23, and the base of the fifth transistor N2 is grounded through a seventh resistor R19.
The fifth triode N2 and the sixth triode N1 are NPN-type triodes, an emitter of the fifth triode N2 is grounded, a collector of the fifth triode N2 is connected to the emitter of the sixth triode N1, a collector of the sixth triode N1 is connected to the control terminal of the start control relay, and a base of the sixth triode N1 is connected to the collector of the fifth triode N2 through an eighth resistor R12.
The collector of the fourth triode P2 is grounded through a third diode D7 and a ninth resistor R13 which are connected in series; the cathode of the third diode D7 is also used for connecting a self-locking state detection end of a controller of the clothes dryer.
The working process of the starting control circuit is briefly described as follows: if the barrel door is in a closed state, the L line and the N line form a loop, a rectangular pulse width exists at a receiving end of the optocoupler IC1, the rectangular pulse width is rectified by a diode D2, after filtering by a capacitor C2, the level at a point C is higher than the turn-on voltage of a MOS1, the MOS1 is turned on, the level at the point D is the same as GND, the triode NR1 is turned off, and the level at the point B is 5V. At this time, if the start key is pressed, the level of the point a is instantaneously higher than 0.7V, the NPN transistor N3 is immediately in saturated conduction, the potential of the point F is pulled to the ground, the PNP transistors P1 and P2 are in saturated conduction, and after the PNP transistor P1 is in conduction, the level of the point a is higher than 0.7V, so that the NPN transistor N3 and the PNP transistor P1 are kept in respective states, and the circuit is in a locked state. Because the PNP triode P2 is turned on, the NPN triode N2 is also in a saturation conduction state, and the NPN triode N2 controls the GND of the NPN triode N1, at this time, if the MCU Load Control terminal (MCU _ Load _ Control) is at a high level +5V, the relay K1 can Control the Load action, and the clothes dryer can operate. And the point E is a detection port of the self-locking state of the circuit, is connected to an input port of the MCU, and can detect the state of the self-holding circuit in real time.
When the barrel door is opened, the receiving end of the optocoupler IC1 has no waveform, the capacitor C2 discharges due to the existence of the diode D2, the resistors R6 and R9, after the capacitor D2 discharges light, the potential of the point C is pulled to the ground, the MOS1 is turned off, the potential of the point D is high, the NPN triode NR1 is in saturated conduction, and the potential of the point B is pulled to the ground. Because the diode D4 is a schottky diode and the conduction voltage drop is about 0.3V, the potential at the point a is 0.3V and is less than the saturation turn-on voltage of 0.7V of the NPN transistor N3, the NPN transistor N3 is turned off, the potential at the point F is pulled high, the PNP transistors P1 and P2 are rapidly turned off, the self-holding state of the circuit is broken, the NPN transistor N2 is also turned off, and at this time, the relay K1 is released, the Load does not work, and the MCU Load Control terminal (MCU _ Load _ Control) does not work even if it is at a high level. The potential of the point E is low, and the MCU can judge that the self-holding circuit is released.
The condition for the self-sustaining circuit to work is that the strong door switch must be closed, i.e. the tub door must be closed. After the self-holding circuit is operated, if the strong door switch is turned off, that is, the barrel door is opened, the self-holding circuit is released, and the load cannot operate, and as can be seen from the figure I, the L line passes through the strong door switch, then passes through the contact of K1 to reach the load, and then returns to the N line to form a loop. The use of a strong switch also allows for safer load control.
The MCU self-locking state Detection end (MCU _ Door Switch _ Detection) is an MCU Detection opening in a strong Door Switch state to judge the state of a strong Door Switch, namely the state of a clothes dryer barrel Door.
The embodiment adopts the triode to form the self-locking circuit, the conduction voltage drop of the Schottky diode is lower than 0.7V to remove the self-locking circuit, the strong switch is adopted, the detection of the strong switch is digital level, the digital level is obtained by rectification and filtering of the diode and the capacitor, and the control of the relay of the embodiment has the precondition that the triode for controlling the GND must be in saturated conduction, namely, the self-locking circuit works. Because the circuit adopts the commonly used triode and diode, the price is low and the service life is long.
The above-described aspects may be implemented individually or in various combinations, and such variations are within the scope of the present invention.
Finally, it should be noted that: the above examples are only for illustrating the technical solutions of the present invention, and are not limited thereto. Although the present invention 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; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.