Power supply discharging circuit for ink-jet printer

Abstract

The utility model discloses a power supply discharge circuit used for an ink-jet printer. The power supply discharge circuit comprises a power supply input module, an overcurrent protection module, a voltage protection module and a voltage stabilization module. Stable input, current and voltage monitoring protection and stable voltage output of an external power supply are realized through the power supply discharge circuit of the power supply input module, the overcurrent protection module, the voltage protection module and the voltage stabilization module, and the system is ensured not to trigger abnormal conditions during repeated startup and shutdown through the design of the power supply discharge circuit. Through the over-current protection module and the voltage protection module, current and voltage in the circuit are effectively monitored and protected, misoperation is prevented, safety and controllability of the system are improved, and the problems of abnormal triggering and misoperation caused by the fact that a direct-current power supply box lacks a discharge mechanism in the prior art are effectively solved. And the stability, safety and reliability of the system are improved, so that the quality and performance of power supply processing control are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply, in particular to a power supply discharge circuit for an inkjet printer. Background Art

[0002] There is a major pain point in the power processing control of the printer. First of all, most of the commonly used DC power boxes selected by customers do not have a discharge mechanism, so when repeatedly turning the machine on and off, the system will always be triggered abnormally. Therefore, the power discharge mechanism has become an important factor in engineering circuit design. The DC power box has advantages in ease of use, performance and reliability in engineering implementation, and the price is relatively reasonable. However, there is also a problem that cannot be ignored, that is, when the customer uses the machine, the machine is manually operated. Since the power box design lacks a discharge mechanism, the system occasionally triggers a false action. For this reason, we have introduced a new power discharge design, which allows customers to choose various types of power boxes by themselves to ensure the normal operation of the system. Summary of the invention

[0003] In order to solve the above-mentioned technical problems, the utility model provides a power supply discharge circuit for an inkjet printer.

[0004] The technical solution of the utility model is achieved in this way:

[0005] A power supply discharge circuit for an inkjet printer includes a power supply input module, an overcurrent protection module, a voltage protection module and a voltage stabilization module.

[0006] The power input module is used to receive external power input, connect to a 24V DC power supply, and ensure stable input of the external power supply;

[0007] The overcurrent protection module is used to monitor the current in the circuit and to protect the circuit from overload and damage when the current exceeds a set range;

[0008] The voltage protection module is used to monitor the voltage in the circuit and perform protection when the voltage exceeds a set range to ensure that the voltage in the circuit is within a safe range;

[0009] The voltage stabilizing module is used to stabilize the voltage in the circuit to ensure the output of a stable voltage under changing power supply conditions, and includes a voltage stabilizer TLV431 to maintain the normal operating voltage of key components in the circuit.

[0010] Furthermore, the power input module includes a 24V external power supply, which is respectively connected to the drain of the NMOS transistor Q59, the voltage protection module and one end of the diode D56, and the other end of the diode D56 is connected to the voltage stabilization module through the first resistor R325.

[0011] Furthermore, the gate of the NMOS transistor Q59 is connected to the collector of the first transistor Q55 of the overcurrent protection module, and the source of the NMOS transistor Q59 is connected to one end of the second resistor R321.

[0012] Furthermore, the overcurrent protection module includes a first transistor Q55, a base of the first transistor Q55 is also connected to one end of a third resistor R323 through a second resistor R321, and an emitter of the first transistor Q55 is respectively connected to the other end of the third resistor R323 and the ground.

[0013] Further, the voltage protection module includes a second transistor Q22, the base of the second transistor Q22 is connected to the power input module through the fourth resistor R319, the collector of the second transistor Q22 is connected to one end of the first capacitor C109 through the fifth resistor R320, one end of the first capacitor C109 is also connected to one end of the sixth resistor R322, one end of the sixth resistor R322 is also connected to the collector of the first transistor Q55, the other end of the first capacitor C109 is also respectively connected to the other end of the sixth resistor and the emitter of the first transistor Q55, and the emitter of the second transistor Q22 is connected to the voltage stabilizing module.

[0014] Furthermore, the voltage stabilizing module includes a TLV431 chip, a first pin of the TLV431 chip is respectively connected to one end of the seventh resistor R325 and one end of the eighth resistor R326, the other end of the eighth resistor R326 is connected to the other end of the seventh resistor R325 through the second capacitor C114, the other end of the seventh resistor R325 is also connected to the second pin of the TLV431 chip, the second pin of the TLV431 chip is connected to the voltage protection module, and the third pin of the TLV431 chip is respectively connected to the other end of the eighth resistor R326 and the ground.

[0015] Furthermore, the first transistor Q55 is an NPN transistor, and forms an overcurrent protection circuit with the third resistor R323 and the second resistor R321. The third resistor R323 is a current limiting sampling resistor, the second transistor Q22 is a PNP transistor, and the reference voltage of the TLV431 chip is 1.24V. Beneficial Effects

[0016] The utility model realizes stable input of external power supply, monitoring and protection of current and voltage, and stable output voltage through the power discharge circuit of the power input module, overcurrent protection module, voltage protection module and voltage stabilizing module. Through the design of the power discharge circuit, it is ensured that the system will not trigger abnormal conditions when repeatedly turning on and off the machine, thereby improving the stability and reliability of the system. Through the overcurrent protection and voltage protection modules, the current and voltage in the circuit are effectively monitored and protected to prevent false operations, thereby improving the safety and controllability of the system. It effectively solves the problems of abnormal triggering and false operations caused by the lack of discharge mechanism in the DC power supply box existing in the background technology, improves the stability, safety and reliability of the system, and thus improves the quality and performance of power processing control. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the system block diagram structure of the utility model;

[0018] Figure 2 It is a circuit design diagram of the utility model. DETAILED DESCRIPTION

[0019] like Figure 1-Figure 2 As shown, the utility model is a power supply discharge circuit for an inkjet printer, comprising a power supply input module, an overcurrent protection module, a voltage protection module and a voltage stabilizing module.

[0020] The power input module is used to receive external power input, connect to a 24V DC power supply, and ensure stable input of the external power supply;

[0021] The overcurrent protection module is used to monitor the current in the circuit and to protect the circuit from overload and damage when the current exceeds a set range;

[0022] The voltage protection module is used to monitor the voltage in the circuit and perform protection when the voltage exceeds a set range to ensure that the voltage in the circuit is within a safe range;

[0023] The voltage stabilizing module is used to stabilize the voltage in the circuit to ensure the output of a stable voltage under changing power supply conditions, and includes a voltage stabilizer TLV431 to maintain the normal operating voltage of key components in the circuit.

[0024] It plays an important role in the power discharge circuit of the inkjet printer, ensuring the stable operation of the circuit, protecting key components from abnormal current and voltage, and improving the stability, safety and reliability of the system.

[0025] Furthermore, the power input module includes a 24V external power supply, which is respectively connected to the drain of the NMOS transistor Q59, the voltage protection module and one end of the diode D56, and the other end of the diode D56 is connected to the voltage stabilization module through the first resistor R324.

[0026] By connecting to the voltage protection module and diode D56, the voltage in the circuit is protected and stably controlled to ensure the safe operation and stability of key components in the circuit. By connecting to the voltage stabilizing module, the voltage in the circuit is stably controlled to maintain the normal operating voltage of key components and improve the stability and reliability of the system.

[0027] Furthermore, the gate of the NMOS transistor Q59 is connected to the collector of the first transistor Q55 of the overcurrent protection module, and the source of the NMOS transistor Q59 is connected to one end of the second resistor R321.

[0028] The three pins of the NMOS transistor Q59 are respectively a gate Gate, a source Source and a drain Drain. The gate Gate is used to control the on and off states of the NMOS, the source Source is used for current outflow, and the drain Drain is used for current inflow, so as to realize the control and regulation of the current in the circuit.

[0029] Furthermore, the overcurrent protection module includes a first transistor Q55, the base of which is also connected to one end of a third resistor R323 through a second resistor R321, so as to accurately detect the current in the circuit and protect the circuit from overcurrent. The emitter of the first transistor Q55 is respectively connected to the other end of the third resistor R323 and the ground, so as to ensure that the overcurrent protection mechanism can be activated in time when the current is overloaded, thereby protecting the key components in the circuit and improving the stability and safety of the system.

[0030] The Q55 transistor is used to detect and protect the current in the circuit, ensuring that the protection mechanism can be effectively triggered when the current exceeds the set range, protecting the components in the circuit from overcurrent damage.

[0031] Further, the voltage protection module includes a second transistor Q22, the base of which is connected to the power input module through a fourth resistor R319 to ensure monitoring and control of the voltage in the circuit, the collector of which is connected to one end of the first capacitor C109 through a fifth resistor R320 to filter and stabilize the voltage in the circuit, one end of the first capacitor C109 is also connected to one end of the sixth resistor R322, one end of the sixth resistor R322 is also connected to the collector of the first transistor Q55, the other end of the first capacitor C109 is also respectively connected to the other end of the sixth resistor and the emitter of the first transistor Q55, and the emitter of the second transistor Q22 is connected to the voltage stabilization module.

[0032] Through the connection of capacitor C109, the voltage in the circuit is filtered and stabilized, thereby improving the stability and reliability of the system. The voltage in the circuit is monitored and protected through the transistor Q22, thereby ensuring the voltage stability in the circuit and protecting key components from voltage anomalies, thereby improving the stability and safety of the system.

[0033] Furthermore, the voltage stabilizing module includes a TLV431 chip, a first pin of the TLV431 chip is respectively connected to one end of the seventh resistor R325 and one end of the eighth resistor R326, the other end of the eighth resistor R326 is connected to the other end of the seventh resistor R325 through the second capacitor C114, the other end of the seventh resistor R325 is also connected to the second pin of the TLV431 chip, the second pin of the TLV431 chip is connected to the voltage protection module, and the third pin of the TLV431 chip is respectively connected to the other end of the eighth resistor R326 and the ground.

[0034] The TLV431 chip achieves stable control of the voltage in the circuit through connection to ensure that the voltage in the circuit is constant. The connection method of the TLV431 chip ensures the output of stable voltage, and through connection with the voltage protection module, ensures that the voltage in the circuit operates within a safe range.

[0035] Furthermore, the first transistor Q55 is an NPN transistor, and forms an overcurrent protection circuit with the third resistor R323 and the second resistor R321. The third resistor R323 is a current limiting sampling resistor, the second transistor Q22 is a PNP transistor, and the reference voltage of the TLV431 chip is 1.24V.

[0036] TLV431 is a three-terminal voltage regulator used as a voltage stabilizer. TLV431 controls the output voltage to stabilize at a set value by comparing the input voltage with the internal reference voltage. TLV431 is used to stabilize the voltage, ensuring that the second capacitor C114 is charged to the set value and maintains the set voltage when the power is off, playing a voltage stabilization role. TLV431 adjusts the output voltage by comparing the input voltage with the set voltage, maintaining the set voltage of the second capacitor C114, thereby achieving stable control of the voltage.

[0037] The second transistor Q22 is a PNP transistor, and the voltage between the base and the emitter controls the current between the collector and the emitter. When the base voltage is negative, the PNP transistor is turned on; when the base voltage is positive, the PNP transistor is turned off. When the voltage is off, the voltage change between its base and the emitter is used to control the voltage stability of the capacitor to ensure the normal operation of the circuit.

[0038] Working principle:

[0039] When powered on, 24V charges the second capacitor C114 through the diode D56 and the first resistor R324. When the voltage reaches the set value, TLV431 stabilizes the voltage, U= (R325+ R326) / R326*1.24V;

[0040] When the 24V is turned off during power failure, the second capacitor C114 maintains the set voltage, the potential of the emitter of the second transistor Q22 connected to the second capacitor C114 remains unchanged, and the base potential decreases as the 24V is turned off. When the decreased potential is 0.7V lower than the set potential, the second transistor Q22 is turned on, and the voltage stored in the second capacitor C114 is powered on the gs electrode of the NMOS transistor Q59 through the second transistor Q22 and the fifth resistor R320 and the third resistor R323. The NMOS transistor Q59 is turned on, and the 24V power supply will accelerate the discharge through the NMOS transistor Q59 and the third resistor R323. During the discharge process, the resistance current of the third resistor R323 increases. When the voltage difference between the two ends rises to 0.7V, the first transistor Q55 is turned on, and the NMOS transistor Q59 The gate potential of the NMOS transistor Q59 is pulled down, and the voltage between the gate and the source is less than the turn-on voltage and the NMOS transistor Q59 is turned off. The current of the third resistor R323 decreases, and the voltage drop decreases accordingly. When it is less than 0.7V, the first transistor Q55 is turned off, and the voltage between the gate and the source of the NMOS transistor Q59 increases and returns to the on state, thereby achieving the purpose of dynamic current limiting.

Claims

1. A power supply discharge circuit for an inkjet printer, characterized in that: Including power input module, overcurrent protection module, voltage protection module and voltage stabilization module, The power input module is used to receive external power input, connect to a 24V DC power supply, and ensure stable input of the external power supply; The overcurrent protection module is used to monitor the current in the circuit and to protect the circuit from overload and damage when the current exceeds a set range; The voltage protection module is used to monitor the voltage in the circuit and perform protection when the voltage exceeds a set range to ensure that the voltage in the circuit is within a safe range; The voltage stabilizing module is used to stabilize the voltage in the circuit to ensure the output of a stable voltage under changing power supply conditions, and includes a voltage stabilizer TLV431 to maintain the normal operating voltage of key components in the circuit.

2. A power supply discharge circuit for an inkjet printer according to claim 1, characterized in that: The power input module includes a 24V external power supply, which is respectively connected to the drain of the NMOS transistor Q59, the voltage protection module and one end of the diode D56, and the other end of the diode D56 is connected to the voltage stabilization module through the first resistor R325.

3. A power supply discharge circuit for an inkjet printer according to claim 2, characterized in that: The gate of the NMOS transistor Q59 is connected to the collector of the first transistor Q55 of the overcurrent protection module, and the source of the NMOS transistor Q59 is connected to one end of the second resistor R321.

4. A power supply discharge circuit for an inkjet printer according to claim 3, characterized in that: The overcurrent protection module includes a first transistor Q55, the base of the first transistor Q55 is also connected to one end of the third resistor R323 through the second resistor R321, and the emitter of the first transistor Q55 is respectively connected to the other end of the third resistor R323 and the ground.

5. A power supply discharge circuit for an inkjet printer according to claim 4, characterized in that: The voltage protection module includes a second transistor Q22, the base of which is connected to the power input module through a fourth resistor R319, the collector of which is connected to one end of the first capacitor C109 through a fifth resistor R320, one end of the first capacitor C109 is also connected to one end of the sixth resistor R322, one end of the sixth resistor R322 is also connected to the collector of the first transistor Q55, the other end of the first capacitor C109 is also respectively connected to the other end of the sixth resistor and the emitter of the first transistor Q55, and the emitter of the second transistor Q22 is connected to the voltage stabilization module.

6. A power supply discharge circuit for an inkjet printer according to claim 5, characterized in that: The voltage stabilizing module includes a TLV431 chip, a first pin of the TLV431 chip is respectively connected to one end of the seventh resistor R325 and one end of the eighth resistor R326, the other end of the eighth resistor R326 is connected to the other end of the seventh resistor R325 through the second capacitor C114, the other end of the seventh resistor R325 is also connected to the second pin of the TLV431 chip, the second pin of the TLV431 chip is connected to the voltage protection module, and the third pin of the TLV431 chip is respectively connected to the other end of the eighth resistor R326 and the ground.

7. A power supply discharge circuit for an inkjet printer according to claim 6, characterized in that: The first transistor Q55 is an NPN transistor, and forms an overcurrent protection circuit with the third resistor R323 and the second resistor R321. The third resistor R323 is a current limiting sampling resistor, the second transistor Q22 is a PNP transistor, and the reference voltage of the TLV431 chip is 1.24V.

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