Self-discharging module of power supply box of printer

Abstract

The utility model discloses a self-discharge module of a power supply box of a printer, which comprises an external power supply, a dynamic current limiting circuit, an energy storage capacitor and a voltage trigger circuit, the voltage trigger circuit is composed of a reference voltage chip and a divider resistor, and the dynamic current limiting circuit comprises a sampling resistor and an NMOS (N-channel Metal Oxide Semiconductor) tube; the problems that an existing discharging circuit is complex in structure, low in discharging speed, poor in compatibility and the like are solved, the discharging time is shortened to 2-3 seconds, the efficiency is improved by more than 80%, the discharging voltage can be flexibly adjusted through the divider resistor, and the discharging voltage can be flexibly adjusted through the divider resistor. The modularized design of the utility model is convenient for installation and maintenance, and the compatibility is strong. And the dynamic current-limiting protection circuit avoids over-current damage, and the safety is high.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of printer power supply equipment, especially suitable for a printer power box self-discharge module of digital inkjet printer. BACKGROUND

[0002] The existing DC power box generally lacks self-discharge function, resulting in slow release of residual voltage in the power box after the equipment is turned off, causing delayed power failure. Especially in inkjet printers, this problem can cause device response delay and affect user experience. Although there are some discharge circuits in the prior art, they generally have defects such as complex structure, slow discharge speed, and poor compatibility. SUMMARY

[0003] The utility model discloses a kind of printer power box self-discharge modules to solve the technical problems existing above.

[0004] The utility model provides a kind of printer power box self-discharge module, including external power supply, dynamic current limiting circuit, energy storage capacitor and voltage trigger circuit, the voltage trigger circuit is composed of reference voltage chip and voltage dividing resistance, the dynamic current limiting circuit includes sampling resistance and NMOS tube;The external power supply is connected in parallel with dynamic current limiting circuit, energy storage capacitor and voltage trigger circuit.

[0005] The energy storage capacitor is connected in series with diode and resistance, and the external power supply charges the energy storage capacitor through the diode and the resistance.

[0006] Beneficial effects

[0007] The utility model solves the problems such as complex structure, slow discharge speed and poor compatibility of the current discharge circuit, shortens the discharge time to 2-3 seconds, improves the efficiency by more than 80%, and the discharge voltage of the utility model can be flexibly adjusted by voltage dividing resistance. The modular design of the utility model is convenient for installation and maintenance, and has strong compatibility. The dynamic current limiting protection circuit avoids overcurrent damage and has high safety. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 It is the circuit schematic diagram of the utility model.

[0009] In the figure: Q22-PNP triode; Q59-NMOS tube; Q55-NPN triode; U41-TLV431 reference chip; R323-sampling resistance; C114-energy storage capacitor; voltage dividing resistance-R326; 24V-external power supply; D56-diode; R320-current limiting resistance. DETAILED DESCRIPTION

[0010] As Figure 1 shown, the utility model discloses a kind of printer power box self-discharge modules.

[0011] The utility model provides a power box self -discharge module of printer, including external power supply, dynamic current -limiting circuit, energy storage capacitor and voltage trigger circuit, voltage trigger circuit is by reference voltage chip and voltage dividing resistance constitutes, dynamic current -limiting circuit includes sampling resistance and NMOS pipe, external power supply is parallel with dynamic current -limiting circuit, energy storage capacitor and voltage trigger circuit.

[0012] The voltage dividing resistance has two, including voltage dividing resistance R325 and voltage dividing resistance R326 respectively.

[0013] The dynamic current -limiting circuit detects current through the sampling resistance, controls the on-off of the NMOS pipe to the current, and realizes the constant current discharge.

[0014] The dynamic current -limiting circuit further includes a triode, and the triode is connected in series with the voltage dividing resistance R325 and the voltage dividing resistance R326.

[0015] The energy storage capacitor is connected in series with a diode and a resistor, and the external power supply charges the energy storage capacitor through the diode and the resistor.

[0016] In the utility model, the external power supply charges the energy storage capacitor C114 through the diode D56 and the resistor R324, and when the voltage reaches 19.84V, the reference chip U41 triggers the PNP triode Q22 to conduct. When charging to the set value, the TLV431 stable voltage U=(R325+R326) / R326*1.24V; according to the matching parameters, U=(150K+10K) / 10K*1.24V=19.84V at this time.

[0017] When discharging, the energy storage capacitor C114 drives the NMOS pipe Q59 to conduct through the Q22 PNP triode and the current-limiting resistor R320, and the residual voltage NMOS pipe is quickly released through the Q59 and the sampling resistor R323.

[0018] When the voltage difference of the sampling resistor R323 exceeds 0.7V, the NPN triode Q55 conducts and pulls down the gate voltage of the NMOS pipe Q59 to limit the discharge current to 350mA, realizing safe discharge.

[0019] For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and can be realized in other specific forms without departing from the spirit or basic characteristics of the utility model. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting, and the scope of the utility model is defined by the appended claims rather than the above description, and therefore all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the utility model.

Claims

1. A power pack self-discharge module of a printer, characterized by, It comprises an external power supply, a dynamic current limiting circuit, an energy storage capacitor and a voltage trigger circuit, the voltage trigger circuit is composed of a reference voltage chip and a voltage dividing resistor, the dynamic current limiting circuit comprises a sampling resistor and an NMOS tube; the external power supply is connected in parallel with the dynamic current limiting circuit, the energy storage capacitor and the voltage trigger circuit.

2. A power pack self-discharge module for a printer according to claim 1, wherein, The voltage dividing resistor has two, respectively comprising a voltage dividing resistor R325 and a voltage dividing resistor R326.

3. The power pack self-discharge module of a printer according to claim 1, wherein, The dynamic current limiting circuit detects current through the sampling resistor and controls the on-off of the current by the NMOS tube to realize constant current discharge.

4. The power pack self-discharge module of a printer according to claim 1, wherein, The dynamic current limiting circuit further comprises a triode, which is connected in series with the voltage dividing resistor R325 and the voltage dividing resistor R326.

5. The power pack self-discharge module of a printer according to claim 1, wherein, The energy storage capacitor is connected in series with a diode and a resistor, and the external power supply charges the energy storage capacitor through the diode and the resistor.

Images