Power supply protection circuit, spray head board card and ink-jet printing equipment

Abstract

The utility model discloses a power supply protection circuit, a nozzle board card and ink-jet printing equipment, and relates to the technical field of power supply protection. The ink-jet printing equipment comprises a nozzle, and the power supply protection circuit comprises a switching circuit of which the output end is used for being connected with the power end of the nozzle; the voltage detection circuit is connected with the power supply input end and is used for detecting the voltage of the power supply input end and outputting a corresponding voltage detection signal; the current detection circuit is electrically connected with the output end of the switching circuit; the current detection circuit is used for detecting the working current of the nozzle and outputting a corresponding current detection signal; the main control circuit is respectively connected with the controlled end of the switching circuit, the output end of the voltage detection circuit and the output end of the current detection circuit; wherein the main control circuit is used for controlling the on-off state of the switching circuit according to the voltage detection signal and / or the current detection signal. The utility model aims to improve the safety when the nozzle in the ink-jet printing equipment is started and works.

Description

TECHNICAL FIELD

[0001] The utility model relates to power supply protection technical field especially relates to a power supply protection circuit, shower head board card and ink jet printing equipment. BACKGROUND

[0002] In ink jet printer, the nozzle needs to be controlled accurately to ensure that the ink drop can accurately fall on the predetermined position of the printed article, and the work of the nozzle depends on the voltage to activate the nozzle to release the ink drop. The voltage input to the nozzle is output by the circuit board in the ink jet printer. When the voltage output by the circuit board is in an abnormal state, the risk of the nozzle work is increased, and the safety and stability of the work are reduced. SUMMARY

[0003] The main purpose of the utility model is to provide a power supply protection circuit, shower head board card and ink jet printing equipment, which aims to improve the safety of the nozzle start and work in the ink jet printing equipment.

[0004] To achieve the above purpose, the power supply protection circuit provided by the utility model is applied to the ink jet printing equipment, and the ink jet printing equipment comprises a nozzle, and the power supply protection circuit comprises:

[0005] A switching circuit, the input end of the switching circuit is connected with the power input end, and the output end of the switching circuit is used for being connected with the power supply end of the nozzle;

[0006] A voltage detection circuit, the voltage detection circuit is connected with the power input end; the voltage detection circuit is used for detecting the voltage of the power input end and outputting a corresponding voltage detection signal;

[0007] A current detection circuit, the current detection circuit is electrically connected with the output end of the switching circuit; the current detection circuit is used for detecting the working current of the nozzle and outputting a corresponding current detection signal;

[0008] A main control circuit, the main control circuit is connected with the controlled end of the switching circuit, the output end of the voltage detection circuit and the output end of the current detection circuit respectively;

[0009] The main control circuit is used for controlling the on-off state of the switching circuit according to the voltage detection signal and / or the current detection signal.

[0010] In an embodiment, the voltage detection circuit comprises an analog-to-digital conversion circuit, the input end of the analog-to-digital conversion circuit is connected with the power input end, and the analog-to-digital conversion circuit is used for outputting the voltage detection signal after the detected voltage signal of the power input end is analog-to-digital converted.

[0011] In an embodiment, the voltage detection circuit and the main control circuit are integrated in the same control chip.

[0012] In an embodiment, the voltage detection circuit and the switch circuit are integrated in the same power supply chip.

[0013] In an embodiment, the switch circuit and the current detection circuit are integrated in a power management chip, the power management chip comprising an enable pin, an input pin, an output pin, an overcurrent pin, the enable pin and the overcurrent pin being electrically connected to the main control circuit respectively for receiving an enable signal and outputting an overcurrent signal, the input pin being connected to the power input end, and the output pin being electrically connected to the power supply end of the nozzle.

[0014] The power management chip is configured to detect the working current of the nozzle and control the overcurrent pin to output an overcurrent signal to the main control circuit when the working current reaches a preset limit current.

[0015] The main control circuit is configured to output a shutdown signal to the enable pin to shut down the power management chip when the overcurrent signal is received.

[0016] In an embodiment, the power management chip further comprises a limit current setting pin, and the power supply protection circuit further comprises a first resistor, a first end of the first resistor being electrically connected to the limit current setting pin, and a second end of the first resistor being electrically connected to a ground end.

[0017] The power management chip is further configured to set the preset limit current according to the resistance value of the limit current setting pin.

[0018] In an embodiment, the power supply protection circuit further comprises a pull-up circuit, the pull-up circuit being electrically connected to the overcurrent pin of the power management chip.

[0019] In an embodiment, the power supply protection circuit further comprises an input filter circuit, the input filter circuit being electrically connected to the input end of the switch circuit.

[0020] In an embodiment, the power supply protection circuit further comprises an output filter circuit, the output filter circuit being electrically connected to the output end of the switch circuit.

[0021] The utility model further provides a nozzle board card, including circuit board and the power supply protection circuit of any one of the above; the power supply protection circuit is arranged on the circuit board.

[0022] The utility model further provides a kind of ink-jet printing equipment, the ink-jet printing equipment includes nozzle and the power supply protection circuit of any one of the above;Or,

[0023] The inkjet printing device comprises a nozzle and the nozzle board card as described above, and the nozzle board card is electrically connected with the power supply end of the nozzle.

[0024] The utility model discloses technical scheme through adopting a power supply protection circuit, the input end, the output end of switching circuit in power supply protection circuit are connected with power input end respectively, the power supply end of nozzle is connected, and the controlled end of switching circuit is electrically connected with main control circuit, and the on-off state of switching circuit is controlled through main control circuit. Among them, the power supply protection circuit still includes voltage detection circuit and current detection circuit. The input end of voltage detection circuit is connected with power input end to detect the voltage of power input end and output corresponding voltage detection signal to main control circuit. The output end of current detection circuit is electrically connected with switching circuit to detect the working current of nozzle and output corresponding current detection signal to main control circuit. Main control circuit receives voltage detection signal and / or current detection signal to confirm whether the voltage and / or current exported by power input end meet the voltage and current required for the normal work of nozzle. When the voltage and / or current exported by power input end do not meet the voltage and current required for the normal work of nozzle, main control circuit will control switching circuit to disconnect the path between power input end and the power supply end of nozzle, effectively avoiding the problem of nozzle damage due to abnormal voltage and / or current in inkjet printing device, and improving the safety of nozzle start and work in inkjet printing device. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained from the structure shown in the drawings without creative labor.

[0026] Figure 1 It is a structural schematic diagram of the power supply protection circuit of the utility model;

[0027] Figure 2 It is a circuit schematic diagram of one embodiment of the power supply protection circuit of the utility model;

[0028] Figure 3 It is a circuit schematic diagram of another embodiment of the power supply protection circuit of the utility model;

[0029] Figure 4 It is a circuit schematic diagram of still another embodiment of the power supply protection circuit of the utility model;

[0030] Figure 5 It is a circuit schematic diagram of still another embodiment of the power supply protection circuit of the utility model;

[0031] Figure 6 Connection diagram of an embodiment of the inkjet printing device of the present application;

[0032] Figure 7 Connection diagram of another embodiment of the inkjet printing device of the present application.

[0033] Brief Description of the Drawings:

[0034] 10, switch circuit; 20, voltage detection circuit; 30, current detection circuit; 40, main control circuit; 50, pull-up circuit; 60, input filter circuit; 70, output filter circuit; 100, power supply protection circuit; 200, nozzle; 300, nozzle board card; 1000, inkjet printing device; R1-R2, first resistor-second resistor; C1-C2, first capacitor-second capacitor; VIN, input pin; VOUT, output pin; EN, enable pin; ILIM, current limit setting pin; nFAULT, overcurrent pin.

[0035] The implementation, functional features and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0037] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative positional relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directional indications will also change accordingly.

[0038] In addition, the description of "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of those skilled in the art, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection required by the present application.

[0039] In an inkjet printer, the nozzle needs to be controlled accurately to ensure that the ink droplets can accurately fall on the predetermined position of the printed object, and the working of the nozzle depends on the voltage to activate the nozzle to release the ink droplets. The voltage input to the nozzle is output by the circuit board in the inkjet printer. When the voltage output by the circuit board is in an abnormal state, the risk of the working of the nozzle is increased, and the safety and stability of the working of the nozzle are reduced.

[0040] Therefore, with reference to Figure 1 and Figure 6 The utility model provides a kind of power supply protection circuit 100, it is applied to inkjet printing equipment 1000, inkjet printing equipment 1000 includes nozzle 200, power supply protection circuit 100 is electrically connected with nozzle 200, power supply protection circuit 100 includes switching circuit 10, voltage detection circuit 20, current detection circuit 30 and main control circuit 40.

[0041] The input end of switching circuit 10 is connected with power input end, and the output end of switching circuit 10 is used to connect with the power end of nozzle 200;Voltage detection circuit 20 is connected with power input end;Voltage detection circuit 20 is used to detect the voltage of power input end, and output corresponding voltage detection signal;Current detection circuit 30 is electrically connected with the output end of switching circuit 10;Current detection circuit 30 is used to detect the working current of nozzle 200, and output corresponding current detection signal;Main control circuit 40 is connected with the controlled end of switching circuit 10, the output end of voltage detection circuit 20 and the output end of current detection circuit 30 respectively;Wherein, main control circuit 40 is used to control the on-off state of switching circuit 10 according to voltage detection signal and / or current detection signal.

[0042] In the embodiment, switching circuit 10 can be realized by at least one switch tube, such as MOS tube, IGBT tube, thyristor, triode, power tube, etc., and / or at least one switching device, such as contactor, circuit breaker and relay. In addition, switching circuit 10 can also be realized by a switching chip with corresponding function. Wherein, power input end and the input end of switching circuit 10 can be connected by bolt or welding. Switching circuit 10 can be in open or closed state under the control of main control circuit 40, to turn on or turn off the path between power input end and the power end of nozzle 200. When inkjet printing equipment 1000 is triggered and in normal working state, main control circuit 40 will receive trigger signal and output switching on signal to switching circuit 10, so that switching circuit 10 is in on state, to make nozzle 200 work.

[0043] It can be understood that in the inkjet printing device 1000, the printhead 200 needs accurate power supply voltage to ensure the accuracy and consistency of its work. Therefore, in the present embodiment, the voltage detection circuit 20 is adopted to detect the voltage of the power supply required to be input to the printhead 200, so as to confirm that the voltage meets the power requirement. The voltage detection circuit 20 can be implemented by using a voltage dividing circuit, a differential amplification circuit, a comparator circuit, or a voltage sampling chip, etc. Taking the voltage dividing circuit as an example, the voltage dividing resistor circuit is composed of two series resistors, one end of one resistor is connected to the power input end, the other end is connected to one end of the other resistor, and the other end of the second resistor is grounded. The node between the two resistors is connected to the analog input port of the master control circuit 40. The master control circuit 40 can convert the input analog voltage signal into a digital voltage signal through the built-in analog-to-digital conversion module, and calculate the actual input voltage value through the preset software algorithm. The master control circuit 40 confirms whether the voltage of the power supply end to be output to the printhead 200 is overvoltage or undervoltage by processing the voltage detection signal, and then outputs a corresponding control signal to the switch circuit 10, so that the printhead 200 is powered on only under the condition that the input voltage meets the power requirement.

[0044] In the present embodiment, the current detection circuit 30 can be implemented by using a resistor shunt, a Hall current sensor, a Rogowski coil current sensor, a fluxgate current sensor, an optical fiber current sensor, etc. The current detection circuit 30 is electrically connected to the output end of the switch circuit 10, so as to detect the current flowing through the switch circuit 10 to the power supply end of the printhead 200, and output a current detection signal to the master control circuit 40. It can be understood that in the inkjet printing device 1000, overcurrent may cause the failure or damage of the printhead 200. Therefore, the master control circuit 40 can confirm whether the current input to the power supply end of the printhead 200 is overcurrent through the current detection signal, and then control the switch circuit 10 to turn on or off the path between the power input end and the power supply end of the printhead 200, effectively avoiding the problem of damage of the printhead 200 due to overcurrent.

[0045] In the embodiment, the main control circuit 40 can be implemented by a main controller, such as a SOC (System On Chip), an MCU (Microcontroller Unit), a DSP (Digital Signal Process), an FPGA (Field Programmable Gate Array), or the like integrated circuit. By being electrically connected with the output end of the voltage detection circuit 20, the output end of the current detection circuit 30, and the controlled end of the switch circuit 10 respectively, the voltage detection signal and the current detection signal are acquired, and whether the voltage detection signal and the current detection signal meet the power supply requirement of the nozzle 200 is confirmed, and then a corresponding control signal is output to the switch circuit 10, so that the switch circuit 10 turns on or turns off the path between the power input end and the power supply end of the nozzle 200, and the safety of the nozzle 200 is effectively ensured.

[0046] The input end and the output end of the switching circuit 10 in the power supply protection circuit 100 are connected with the power input end respectively, the power supply end of the nozzle 200 is connected, the controlled end of the switching circuit 10 is electrically connected with the master control circuit 40, and the on-off state of the switching circuit 10 is controlled through the master control circuit 40. The power supply protection circuit 100 further comprises a voltage detection circuit 20 and a current detection circuit 30. The input end of the voltage detection circuit 20 is connected with the power input end, so that the voltage of the power input end is detected, and the corresponding voltage detection signal is output to the master control circuit 40. The current detection circuit 30 is electrically connected with the output end of the switching circuit 10, so that the working current of the nozzle 200 is detected, and the corresponding current detection signal is output to the master control circuit 40. The master control circuit 40 receives the voltage detection signal and / or the current detection signal, so as to confirm whether the voltage and / or the current output by the power input end meet the voltage and current required for the normal working of the nozzle 200. For example, the voltage input by the power input end is greater than a certain voltage threshold, that is, the voltage output by the power input end is overvoltage; the voltage input by the power input end is less than a certain voltage threshold, that is, the voltage output by the power input end is under-voltage; the current of the power input end is greater than a certain current threshold, that is, the current output by the power input end is overcurrent. Therefore, the voltage and current output by the power input end need to be within the preset voltage threshold and the preset current threshold, so as to meet the voltage and current required for the normal working of the nozzle 200. When the voltage and / or the current output by the power input end do not meet the voltage and current required for the normal working of the nozzle 200, the master control circuit 40 controls the switching circuit 10 to disconnect the path between the power input end and the power supply end of the nozzle 200, effectively avoiding the problem that the nozzle 200 in the inkjet printing equipment 1000 is damaged due to abnormal voltage and / or current, and improving the safety of the nozzle 200 in the inkjet printing equipment 1000 during starting and working.

[0047] In an embodiment of the utility model, voltage detection circuit 20 includes analog-digital conversion circuit, the input end of analog-digital conversion circuit is connected with power input end, analog-digital conversion circuit is used to carry out analog-digital conversion to the voltage signal of detected power input end, and output voltage detection signal.

[0048] In the embodiment, the voltage detection circuit 20 comprises an analog-to-digital conversion circuit, so that the corresponding digital signal is directly output to the main control circuit 40. Further, in order to reduce the influence of noise, the voltage signal is usually subjected to some filtering processing before being input to the analog-to-digital conversion circuit, for example, an RC filter is used to smooth the signal. The preprocessed analog voltage signal is input to the analog-to-digital conversion circuit for analog-to-digital conversion, so as to convert the continuously changing voltage signal into a series of discrete digital values, which are directly output to the main control circuit 40. The main control circuit 40 determines whether the voltage of the power input end meets the power consumption requirement of the nozzle 200 through the output result of the analog-to-digital conversion circuit. By including the analog-to-digital conversion circuit in the voltage detection circuit 20, the voltage detection can be more convenient and accurate, and the power supply protection circuit 100 can be easily realized to realize automatic control. In addition, the voltage signal to be detected can also be reduced to a level suitable for the input range of the analog-to-digital conversion circuit through a voltage dividing circuit or other means. In some embodiments, the analog-to-digital conversion circuit can be an analog-to-digital converter (ADC) chip.

[0049] Optionally, the voltage detection circuit 20 and the main control circuit 40 are integrated in the same control chip.

[0050] In the embodiment, the main control circuit 40 is integrated with the analog-to-digital conversion circuit and has a built-in voltage detection function, so that the voltage detection circuit 20 can be directly integrated inside the main control circuit 40 without additional external hardware, i.e., the voltage detection circuit 20 and the main control circuit 40 are integrated in the same control chip. Specifically, the analog-to-digital conversion circuit inside the control chip can be directly connected to the pin whose voltage needs to be monitored, and by configuring the relevant registers, the analog-to-digital conversion circuit can be started to sample and convert the analog voltage signal into a digital signal. The analog-to-digital conversion circuit needs a reference voltage for quantization, which can be an internal reference source or a stable voltage provided externally. Further, the main control circuit 40 can set a voltage threshold, so that an interrupt or flag bit is generated when the voltage exceeds the set range, so that the main control circuit 40 responds to the voltage change immediately upon receiving an abnormal voltage detection signal. By integrating the voltage detection circuit 20 into the main control circuit 40, the hardware design can be simplified, and the overall performance and response speed of the system can be improved.

[0051] Optionally, the voltage detection circuit 20 and the switching circuit 10 are integrated in the same power supply chip, which can be electrically connected with the main control circuit 40 to improve the integration of the power supply protection circuit 100 and reduce the complexity of the circuit design. The power supply chip can be selected from the chips integrated with the voltage detection circuit 20 and the switching circuit 10 in the prior art, which are not listed here.

[0052] ReferenceFigure 2 In the embodiment of the utility model, switch circuit 10 and current detection circuit 30 are integrated in power management chip U1, power management chip U1 includes enable foot EN, input foot VIN, output foot VOUT, overcurrent foot nFAULT, enable foot EN, overcurrent foot nFAULT are electrically connected with main control circuit 40 respectively, enable foot EN is used for receiving the enable signal sent by main control circuit 40, overcurrent foot nFAULT is used for outputting overcurrent signal to main control circuit 40, input foot VIN is connected with power input end to supply power for power management chip U1, output foot VOUT is electrically connected with the power end of nozzle 200 to supply power for nozzle 200;Power management chip U1 is used for detecting the working current of nozzle 200, and when the working current reaches preset limit current, controls overcurrent foot nFAULT to output overcurrent signal to main control circuit 40;Main control circuit 40 is used for controlling power management chip U1 to disconnect the path between power input end and the power end of nozzle 200 when receiving overcurrent signal.

[0053] In the embodiment, current detection circuit 30 and switch circuit 10 are integrated in power management chip U1, thereby reducing the complexity of structure. In addition, power management chip U1 includes multiple connection pins to facilitate connection of different ports. Among them, the enable foot EN of power management chip U1 is electrically connected with the main control circuit 40, used to obtain the control signal input by the main control circuit 40, and then control the conduction or disconnection of the switch circuit 10; the input foot VIN of the current limiting detection circuit is electrically connected with the power input end, used to receive the output voltage of the power input end; the output foot VOUT of the current limiting detection circuit is electrically connected with the power end of the nozzle 200, used to output the output voltage of the power input end to the power end of the nozzle 200; the overcurrent foot nFAULT of the current limiting detection circuit is electrically connected with the main control circuit 40, used to output the overcurrent signal to the main control circuit 40. The power management chip U1 detects the working current of the nozzle 200 through the integrated current detection circuit 30, and outputs the overcurrent signal to the main control circuit 40 when the working current reaches the preset current. For example, a detection resistor is provided in the chip, which is connected in series in the path between the input foot and the output foot in the chip. The voltage difference across the resistor is proportional to the current flowing through it. For example, if the detection resistor is 0.1Ω, when the current flowing through it is 1A, the voltage difference across the resistor will be 0.1V. A comparator circuit is further provided to monitor the voltage difference across the detection resistor. When the detected voltage difference exceeds the preset threshold, it indicates that the current is too large, and the output of the comparator will change, thereby outputting the overcurrent signal. The main control circuit 40 receives the overcurrent signal to control the switch circuit 10 in the power management chip U1 to disconnect the path between the power input end and the power end of the nozzle 200.

[0054] Reference Figure 3In an embodiment of the utility model, power management chip U1 still has current limit setting foot ILIM, power supply protection circuit 100 still includes first resistance R1, first resistance R1's first end is connected with current limit setting foot ILIM, and the second end of first resistance R1 is connected with ground terminal, power management chip U1 is used for setting corresponding preset limit current according to the resistance of current limit setting foot ILIM.

[0055] In the embodiment, power management chip U1 still includes current limit setting foot ILIM, and is connected with first resistance R1, so that when the resistance of first resistance R1 changes, the corresponding preset limit current is set. Wherein, the developer can select the appropriate current limit threshold by adjusting the resistance of first resistance R1 according to the actual use demand, thereby effectively improving the flexibility of power supply protection circuit 100.

[0056] Reference Figure 4 In an embodiment of the utility model, power supply protection circuit 100 further includes pull-up circuit 50, and the pull-up circuit 50 is electrically connected with the overcurrent pin nFAULT of the power management chip U1.

[0057] In the embodiment, the pull-up circuit 50 is realized by using resistance pull-up circuit, transistor pull-up circuit, diode pull-up circuit, etc. In an embodiment, the pull-up circuit 50 includes a second resistance R2. Wherein, the first end of the pull-up circuit 50 is electrically connected with the power supply terminal, and the second end is electrically connected with the overcurrent pin nFAULT of the power management chip U1. By setting the pull-up circuit 50, the pin connected with the main control circuit 40 of the power management chip U1 has an internal pull-up function, and can ensure that the pin is in a high level state when the power management chip U1 does not output an overcurrent signal. Wherein, it can be understood that the overcurrent signal at this time is a low level signal, so as to ensure the stability of the main control circuit 40 and the judgment of the main control circuit 40 to the interface access state, and avoid false triggering.

[0058] Reference Figure 5 In an embodiment of the utility model, power supply protection circuit 100 further includes input filter circuit 60, and the input filter circuit 60 is electrically connected with the input terminal of the switching circuit 10.

[0059] In the embodiment, the input filter circuit 60 can be realized by using capacitor filter circuit, inductance filter circuit, etc. Wherein, in an embodiment, the input filter circuit 60 adopts capacitor filter circuit, and the input filter circuit 60 includes a first capacitor C1. The input filter circuit 60 is used for filtering high-frequency noise in the power supply input terminal, so that the power supply entering the switching circuit 10 is more pure and stable, so as to avoid the interference of noise on the circuit work. In addition, by using the input filter circuit 60, the fluctuation in the input power supply can be reduced, which helps to protect the subsequent circuit components from the influence of voltage mutation.

[0060] Reference Figure 5 In an embodiment of the present application, the power supply protection circuit 100 further comprises an output filter circuit 70, which is electrically connected with the output end of the switching circuit 10.

[0061] In the present embodiment, the output filter circuit 70 can also be implemented by a capacitor filter circuit, an inductor filter circuit, etc. Among them, the output filter circuit 70 is a capacitor filter circuit, and the output filter circuit 70 comprises a second capacitor C2. The output filter circuit 70 is used to eliminate the ripple and noise in the output voltage of the switching circuit 10, so as to ensure the smoothness of the output voltage. In addition, the output filter circuit 70 is also used for smoothing processing of the output voltage, so that the output is more stable and more suitable for devices such as the nozzle 200 which are sensitive to voltage.

[0062] Please refer to Figure 7 The present application also provides a nozzle board card 300, which comprises a circuit board (not shown in the figure) and the power supply protection circuit 100 according to any one of the above. The power supply protection circuit 100 is arranged on the circuit board. It is worth noting that since the nozzle board card of the present application is based on the power supply protection circuit 100 described above, the embodiments of the nozzle board card of the present application include all the technical solutions of all the embodiments of the power supply protection circuit 100 described above, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0063] In other embodiments, the nozzle board card 300 can also be provided with other circuits, such as a nozzle driving circuit, or a voltage conversion circuit, or a power failure protection circuit, etc., which will not be listed one by one here.

[0064] The present application also provides a nozzle board card 300, which comprises a circuit board (not shown in the figure) and the power supply protection circuit 100 according to any one of the above. The power supply protection circuit 100 is arranged on the circuit board. It is worth noting that since the nozzle board card of the present application is based on the power supply protection circuit 100 described above, the embodiments of the nozzle board card of the present application include all the technical solutions of all the embodiments of the power supply protection circuit 100 described above, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0065] In some embodiments, as shown in Figure 6 The inkjet printing device 1000 comprises the nozzle 200 and the power supply protection circuit 100 according to any one of the above.

[0066] In some embodiments, as shown in Figure 7 The inkjet printing device 1000 comprises the nozzle 200 and the nozzle board card 300 described above, and the nozzle board card 300 is electrically connected with the power supply end of the nozzle 200.

[0067] Since the inkjet printing device 1000 of the present application comprises the power supply protection circuit 100 or the nozzle board card 300 described above, the embodiments of the inkjet printing device 1000 of the present application include all the technical solutions of all the embodiments of the power supply protection circuit 100 or the nozzle board card 300 described above, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0068] In some embodiments, the inkjet printing device 1000 can also include other functional components, such as a print head, a moving component, an ink supply component, etc., the inkjet head 200 and the power supply protection circuit 100 can be arranged in the print head, the print head can be arranged on the moving component, and the ink supply component can be connected to the print head to supply ink to the print head.

[0069] The above merely describes the preferred embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation made by using the content of the present application specification and drawings, or direct / indirect application in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A power supply protection circuit applied to an inkjet printing apparatus including a nozzle, the inkjet printing apparatus comprising: The power supply protection circuit comprises: a switch circuit, an input end of the switch circuit being connected with the power input end, and an output end of the switch circuit being used for being connected with the power supply end of the nozzle; a voltage detection circuit, the voltage detection circuit being connected with the power input end; the voltage detection circuit is used for detecting the voltage of the power input end and outputting a corresponding voltage detection signal; a current detection circuit, the current detection circuit being electrically connected with the output end of the switch circuit; the current detection circuit is used for detecting the working current of the nozzle and outputting a corresponding current detection signal; a main control circuit, the main control circuit being connected with the controlled end of the switch circuit, the output end of the voltage detection circuit and the output end of the current detection circuit respectively; wherein, the main control circuit is used for controlling the on-off state of the switch circuit according to the voltage detection signal and / or the current detection signal.

2. The power supply protection circuit of claim 1, wherein, The voltage detection circuit comprises an analog-to-digital conversion circuit, an input end of the analog-to-digital conversion circuit being connected with the power input end, and the analog-to-digital conversion circuit being used for outputting the voltage detection signal after performing analog-to-digital conversion on the detected voltage signal of the power input end.

3. The power supply protection circuit of claim 1, wherein, The voltage detection circuit and the main control circuit are integrated in the same control chip; or, The voltage detection circuit and the switch circuit are integrated in the same power supply chip.

4. The power supply protection circuit of claim 1, wherein, The switch circuit and the current detection circuit are integrated in a power management chip, the power management chip comprising an enable pin, an input pin, an output pin and an overcurrent pin, the enable pin and the overcurrent pin being electrically connected with the main control circuit respectively and being used for receiving an enable signal and outputting an overcurrent signal respectively, the input pin being connected with the power input end, and the output pin being electrically connected with the power supply end of the nozzle; The power management chip is used for detecting the working current of the nozzle and controlling the overcurrent pin to output an overcurrent signal to the main control circuit when the working current reaches a preset limit current. The main control circuit is used for outputting a closing signal to the enable pin to close the power management chip when the overcurrent signal is received.

5. The power supply protection circuit of claim 4, wherein, The power management chip further comprises a limit current setting pin, and the power supply protection circuit further comprises a first resistor, a first end of the first resistor being electrically connected with the limit current setting pin, and a second end of the first resistor being electrically connected with a ground end; The power management chip is further used for setting the preset limit current according to the resistance value of the limit current setting pin.

6. The power supply protection circuit of claim 4, wherein, The power supply protection circuit further comprises a pull-up circuit, the pull-up circuit being electrically connected with the overcurrent pin of the power management chip.

7. The power supply protection circuit of any one of claims 1 to 6, wherein, The power supply protection circuit further comprises an input filter circuit, the input filter circuit being electrically connected with the input end of the switch circuit.

8. The power supply protection circuit of any one of claims 1 to 6, wherein, The power supply protection circuit further comprises an output filter circuit, the output filter circuit being electrically connected with the output end of the switch circuit.

9. A spray head board card, characterized by The power supply protection circuit comprises a circuit board and the power supply protection circuit as claimed in any one of claims 1 to 8, the power supply protection circuit being arranged on the circuit board.

10. An inkjet printing apparatus, characterized by comprising: The inkjet printing device comprises a nozzle and the power supply protection circuit according to any one of claims 1 to 8, and the power supply protection circuit is electrically connected with a power supply end of the nozzle; or The inkjet printing device comprises a nozzle and the nozzle board card according to claim 9, and the nozzle board card is electrically connected with a power supply end of the nozzle.

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