Hardware protection circuit for short circuit of medical perfusion pump motor

Abstract

The invention discloses a hardware protection circuit for short circuit of a medical perfusion pump motor. The hardware protection circuit comprises a hardware PWM (Pulse Width Modulation) wave sealing circuit, an overcurrent signal latch circuit and an overcurrent protection reset circuit which are matched with one another for use, when the hardware PWM wave sealing circuit has a short circuit phenomenon in a loop, PWM output is quickly stopped so as to protect the MOS tube; the overcurrent signal latch circuit latches an overcurrent protection signal to wait for software detection when a short circuit phenomenon occurs in a loop; the over-current reset circuit resets the latched over-current protection signal to be in an initial state without faults, and resets the over-current signal.

Description

Technical Field

[0001] The invention relates to medical equipment, in particular to a hardware protection circuit for short circuit of a motor of a medical infusion pump. Background Art

[0002] When the infusion pump load motor is short-circuited, the motor drive switch MOSFET needs to be quickly cut off. However, the protection speed is slow through software sampling current, which is easy to damage the switch MOSFET. At this time, a hardware circuit is needed to achieve fast short-circuit protection.

[0003] Therefore, it is necessary to provide a hardware protection circuit for a medical infusion pump motor short circuit to solve the above problems. Summary of the invention

[0004] The purpose of the present invention is to provide a hardware protection circuit for a short circuit of a medical infusion pump motor.

[0005] The present invention achieves the above object through the following technical solutions:

[0006] A hardware protection circuit for a short circuit of a medical perfusion pump motor, comprising a hardware PWM wave-sealing circuit, an overcurrent signal latch circuit, and an overcurrent protection reset circuit that cooperate with each other;

[0007] When there is a short circuit in the hardware PWM wave blocking circuit, the PWM output is quickly stopped to protect the MOS tube;

[0008] When there is a short circuit in the overcurrent signal latch circuit, the overcurrent protection signal will be latched and wait for software detection;

[0009] The overcurrent reset circuit resets the latched overcurrent protection signal to an initial state when there is no fault, and resets the overcurrent signal.

[0010] Furthermore, the overcurrent signal is valid at a low level and is first converted into a high level signal. Specifically, the overcurrent signal OC_Fault1 is converted from a low level to a high level through a transistor Q26.

[0011] Furthermore, after the level conversion, it is given to the latch circuit input through a diode D81 to lock the fault protection signal, ensuring that when the front-end fault signal disappears, the overcurrent protection signal level can be kept unchanged, and a low-level signal is continuously output through interlocking of an NPN transistor Q24 and a PNP transistor Q18.

[0012] Furthermore, the overcurrent protection signal sets the protection signal OC_Protect_EN1 high through the transistor Q20, that is, the low level is converted to a high level through level conversion, the OE pin of the level conversion chip U3 is pulled high, OE is low effective, and the level conversion chip U3 turns off the PWM output.

[0013] Furthermore, the overcurrent fault signal D_OC_Fault1 is pulled low through transistor Q22 and transmitted to the MCU.

[0014] Furthermore, by giving the D_OC_Reset signal, ie, a reset signal at a high level, the latch circuit is reset, the overcurrent protection signal OC_Pretect1 is set low, and the level conversion chip U3 can output PWM normally, thereby forming a reset.

[0015] Furthermore, the diode D81 ensures that after the overcurrent signal is detected, the latch circuit can operate normally and will not be affected by the front-end level conversion circuit.

[0016] Furthermore, the MOS tube Q28 quickly discharges the Vbe voltage of the transistor Q24 to ensure that the transistor Q24 is reliably turned off.

[0017] Compared with the prior art, the present invention has a simple structure and low cost; it realizes the function of rapid short-circuit protection of the motor load of the perfusion pump and improves the reliability of the instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 One of the circuit principle diagrams of the present invention;

[0019] Figure 2 This is the second circuit schematic diagram of the present invention. DETAILED DESCRIPTION

[0020] Example:

[0021] See also Figure 1-2 , this embodiment shows a hardware protection circuit for a short circuit of a medical perfusion pump motor, including a hardware PWM wave sealing circuit, an overcurrent signal latch circuit, and an overcurrent protection reset circuit that cooperate with each other;

[0022] When there is a short circuit in the hardware PWM wave blocking circuit, the PWM output is quickly stopped to protect the MOS tube;

[0023] When there is a short circuit in the overcurrent signal latch circuit, the overcurrent protection signal will be latched and wait for software detection;

[0024] The overcurrent reset circuit resets the latched overcurrent protection signal to an initial state when there is no fault, and resets the overcurrent signal.

[0025] The overcurrent signal is valid at a low level and is first converted into a high level signal. Specifically, the overcurrent signal OC_Fault1 is converted from a low level to a high level through a transistor Q26.

[0026] After the level conversion, it is given to the latch circuit input through a diode D81 to lock the fault protection signal, ensuring that when the front-end fault signal disappears, the overcurrent protection signal level can be kept unchanged, and a low-level signal is continuously output through interlocking of an NPN transistor Q24 and a PNP transistor Q18.

[0027] The overcurrent protection signal sets the protection signal OC_Protect_EN1 high through transistor Q20, that is, the low level is converted to a high level through level conversion, the OE pin of the level conversion chip U3 is pulled high, OE is low effective, and the level conversion chip U3 turns off the PWM output.

[0028] The overcurrent fault signal D_OC_Fault1 is pulled low through transistor Q22 and transmitted to the MCU.

[0029] By giving the D_OC_Reset signal, that is, the reset signal high level, the latch circuit is reset, the overcurrent protection signal OC_Pretect1 is set low, and the level conversion chip U3 can output PWM normally, forming a reset.

[0030] Diode D81 ensures that after an overcurrent signal is detected, the latch circuit can operate normally and will not be affected by the front-end level conversion circuit.

[0031] The MOS tube Q28 quickly discharges the Vbe voltage of the transistor Q24 to ensure that the transistor Q24 is reliably turned off.

[0032] Compared with the prior art, the present invention has a simple structure and low cost; it realizes the function of rapid short-circuit protection of the motor load of the perfusion pump and improves the reliability of the instrument.

[0033] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A hardware protection circuit for a medical infusion pump motor short circuit, characterized in that: It includes hardware PWM wave sealing circuit, overcurrent signal latch circuit and overcurrent protection reset circuit which are used in conjunction with each other; When there is a short circuit in the hardware PWM wave blocking circuit, the PWM output is quickly stopped to protect the MOS tube; When there is a short circuit in the overcurrent signal latch circuit, the overcurrent protection signal will be latched and wait for software detection; The overcurrent reset circuit resets the latched overcurrent protection signal to an initial state when there is no fault, and resets the overcurrent signal.

2. A hardware protection circuit for a medical infusion pump motor short circuit according to claim 1, characterized in that: The overcurrent signal is valid at a low level and is first converted into a high level signal. Specifically, the overcurrent signal OC_Fault1 is converted from a low level to a high level through a transistor Q26.

3. A hardware protection circuit for a medical infusion pump motor short circuit according to claim 2, characterized in that: After the level conversion, it is given to the latch circuit input through a diode D81 to lock the fault protection signal, ensuring that when the front-end fault signal disappears, the overcurrent protection signal level can be kept unchanged, and a low-level signal is continuously output through interlocking of an NPN transistor Q24 and a PNP transistor Q18.

4. A hardware protection circuit for a medical infusion pump motor short circuit according to claim 3, characterized in that: The overcurrent protection signal sets the protection signal OC_Protect_EN1 high through transistor Q20, that is, the low level is converted to a high level through level conversion, the OE pin of the level conversion chip U3 is pulled high, OE is low effective, and the level conversion chip U3 turns off the PWM output.

5. A hardware protection circuit for a short circuit of a medical infusion pump motor according to claim 4, characterized in that: The overcurrent fault signal D_OC_Fault1 is pulled low through transistor Q22 and transmitted to the MCU.

6. A hardware protection circuit for a short circuit of a medical infusion pump motor according to claim 5, characterized in that: By giving the D_OC_Reset signal, that is, the reset signal high level, the latch circuit is reset, the overcurrent protection signal OC_Pretect1 is set low, and the level conversion chip U3 can output PWM normally, forming a reset.

7. A hardware protection circuit for a short circuit of a medical infusion pump motor according to claim 6, characterized in that: Diode D81 ensures that after an overcurrent signal is detected, the latch circuit can operate normally and will not be affected by the front-end level conversion circuit.

8. A hardware protection circuit for a short circuit of a medical infusion pump motor according to claim 7, characterized in that: The MOS tube Q28 quickly discharges the Vbe voltage of the transistor Q24 to ensure that the transistor Q24 is reliably turned off.

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