Motor brake circuit applied to breathing machine

Abstract

The utility model discloses a motor brake circuit applied to a breathing machine, which relates to the technical field of motor driving and comprises a CPU (central processing unit), a motor driving detection circuit and an energy storage circuit. The output end of the CPU processor is electrically connected with the input end of the motor driving detection circuit, the output end of the motor driving detection circuit is electrically connected with the input end of the energy storage circuit, and the output end of the energy storage circuit is electrically connected with the input end of the CPU processor. According to the motor brake circuit provided by the utility model, the inductor is adopted to absorb and store energy, the energy is temporarily stored in the inductor when the motor stops running, and the stored energy is released to start the motor in the next running period, so that the energy waste and overheating phenomena are avoided, and the energy utilization rate is improved. The service life of the battery can be obviously prolonged; and the temperature rise of equipment is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of motor drive, and more specifically, to a motor braking circuit applied to a ventilator. Background Art

[0002] In various types of ventilators, motors are used to drive air so that airflows circulate at a frequency close to the natural breathing frequency of the human body. The motors also have a periodic operation process similar to the breathing frequency (specifically, the process of starting, running, stopping, and restarting).

[0003] Currently, the braking resistor principle is generally adopted in the process of the motor running to stop (or decelerating). That is, when decelerating, the motor coil is connected to a high-power resistor, and the coil current is converted into heat during the deceleration process to reduce the current and decelerate the motor rotor. However, this way of using a braking resistor still has the following defects:

[0004] (1) Energy is wasted. Especially when the ventilator is powered by a battery, the energy is very limited. After being wasted by the braking resistor, the battery life will be greatly shortened.

[0005] (2) The current trend is towards more and more compact portable ventilators. However, the large amount of heat generated by the braking resistor causes the temperature inside the narrow device to rise rapidly, which is not conducive to the long-term reliable operation of the device and thus reduces its service life.

[0006] In addition, if considering using a capacitor for energy storage, the following problems also exist:

[0007] (3) The capacitor has a large volume, which is not conducive to compact portable devices.

[0008] (4) Due to structural reasons, the service life of the capacitor is limited.

[0009] For the problems in the related art, no effective solution has been proposed yet. Summary of the Utility Model

[0010] In view of the problems in the related art, the utility model provides a motor braking circuit applied to a ventilator to overcome the above technical problems existing in the existing related art.

[0011] To this end, the specific technical solution adopted by the utility model is as follows:

[0012] A motor braking circuit applied to a ventilator, comprising a CPU processor, a motor drive detection circuit and an energy storage circuit; the output end of the CPU processor is electrically connected to the input end of the motor drive detection circuit, the output end of the motor drive detection circuit is electrically connected to the input end of the energy storage circuit, and the output end of the energy storage circuit is electrically connected to the input end of the CPU processor.

[0013] Further, the motor drive detection circuit includes a thyristor SCR1, a triode Q5, a field effect transistor Q1, a field effect transistor Q2, a field effect transistor Q3, a field effect transistor Q4, a motor M, a resistor R1, a diode D1, a diode D2, a capacitor C3, a capacitor C4 and an operational amplifier U1;

[0014] One end of the motor M is respectively connected to the source electrode of the field effect transistor Q1, the drain electrode of the field effect transistor Q3, one end of the capacitor C3 and the positive electrode of the diode D1. The drain electrode of the field effect transistor Q1 is respectively connected to the emitter of the triode Q5, the third pin of the thyristor SCR1 and the drain electrode of the field effect transistor Q2. The base of the triode Q5 is connected to the second pin of the CPU processor. The collector of the triode Q5 is connected to the power supply VCC. The first pin of the thyristor SCR1 is connected to the energy storage circuit. The second pin of the thyristor SCR1 is connected to the first pin of the CPU processor. The source electrode of the field effect transistor Q3 is connected to the other end of the capacitor C3 and grounded. The other end of the motor M is respectively connected to one end of the resistor R1 and the positive phase input end of the operational amplifier U1. The other end of the resistor R1 is respectively connected to the source electrode of the field effect transistor Q2, the drain electrode of the field effect transistor Q4, one end of the capacitor C4, the positive electrode of the diode D2 and the negative phase input end of the operational amplifier U1. The output end of the operational amplifier U1 is connected to the fifth pin of the CPU processor. The other end of the capacitor C4 is connected to the source electrode of the field effect transistor Q4 and grounded. The negative electrode of the diode D2 is respectively connected to the negative electrode of the diode D1 and the energy storage circuit.

[0015] Further, the energy storage circuit includes a field effect transistor Q6, a field effect transistor Q7, a field effect transistor Q8, a field effect transistor Q9, an inductor L1, an inductor L2, a resistor R2 and an operational amplifier U2;

[0016] The gate of the field-effect transistor Q6 is connected to the third pin of the CPU processor. The drain of the field-effect transistor Q6 is respectively connected to the first pin of the thyristor SCR1, the source of the field-effect transistor Q9, and one end of the inductor L2. The source of the field-effect transistor Q6 is respectively connected to the negative electrode of the diode D1, the negative electrode of the diode D2, one end of the resistor R2, and the negative-phase input terminal of the operational amplifier U2. The positive-phase input terminal of the operational amplifier U2 is respectively connected to the other end of the resistor R2, the drain of the field-effect transistor Q8, and one end of the inductor L1. The other end of the inductor L1 is respectively connected to the drain of the field-effect transistor Q9 and the drain of the field-effect transistor Q7. The source of the field-effect transistor Q7 is respectively connected to the source of the field-effect transistor Q8 and the other end of the inductor L2. The output terminal of the operational amplifier U2 is connected to the fourth pin of the CPU processor.

[0017] Further, the field-effect transistors Q1 to Q4 and the field-effect transistors Q6 to Q9 are all N-channel field-effect transistors.

[0018] Further, when the motor M is operating normally, the triode Q5 is turned on and the thyristor SCR1 is turned off. At this time, no current passes through the inductor.

[0019] Further, when the motor M stops or decelerates, the triode Q5 and the field-effect transistor Q4 are turned off. At the same time, the thyristor SCR1 and the field-effect transistor Q7 are turned on, so that the inductors L1 and L2 are in a series state. At this time, current flows into the inductor for energy storage.

[0020] The beneficial effects of the present utility model are as follows:

[0021] 1. The motor braking circuit provided by the present utility model uses an inductor to absorb and store energy. When the motor stops running, the energy is temporarily stored in the inductor, and the stored energy is released in the next operating cycle to start the motor. This method not only avoids energy waste and overheating phenomena, but also significantly extends the service life of the battery and reduces the temperature rise of the device.

[0022] 2. Compared with the traditional capacitive energy storage scheme, the motor braking circuit provided by the present utility model has a higher power density and a smaller volume when using an inductor. This further improves the overall performance and service life of the device. In addition, this design helps to improve the energy efficiency and environmental adaptability of the device, making the ventilator more reliable and durable. Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0024] Figure 1 It is a schematic block diagram of a motor brake circuit applied to a ventilator according to an embodiment of the present invention;

[0025] Figure 2 It is a circuit diagram of a motor brake circuit applied to a ventilator according to an embodiment of the present invention;

[0026] Figure 3 It is a schematic diagram of the current flow when the motor brake circuit applied to a ventilator works normally according to an embodiment of the present invention;

[0027] Figure 4 It is a schematic diagram of the charging current flow in the motor brake circuit applied to a ventilator according to an embodiment of the present invention;

[0028] Figure 5 It is a schematic diagram of the current change in the motor brake circuit applied to a ventilator according to an embodiment of the present invention;

[0029] Figure 6 It is a schematic diagram of the current flow during discharge in the motor brake circuit applied to a ventilator according to an embodiment of the present invention.

[0030] In the figure:

[0031] 1. CPU processor; 2. Motor drive detection circuit; 3. Energy storage circuit. Specific embodiments

[0032] To further illustrate each embodiment, the present invention provides accompanying drawings, which are part of the disclosure of the present invention. They are mainly used to illustrate the embodiments and can be used to explain the operating principle of the embodiments in combination with the relevant descriptions in the specification. With reference to these contents, those of ordinary skill in the art should be able to understand other possible implementation manners and the advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are usually used to represent similar components.

[0033] According to an embodiment of the present invention, a motor brake circuit applied to a ventilator is provided.

[0034] Now, the present invention will be further described in conjunction with the accompanying drawings and specific embodiments. As Figure 1 - Figure 2 shown, the motor brake circuit applied to a ventilator according to an embodiment of the present invention includes a CPU processor 1 (main control chip), a motor drive detection circuit 2, and an energy storage circuit 3;

[0035] The output end of the CPU processor 1 is electrically connected to the input end of the motor drive detection circuit 2, the output end of the motor drive detection circuit 2 is electrically connected to the input end of the energy storage circuit 3, and the output end of the energy storage circuit 3 is electrically connected to the input end of the CPU processor 1.

[0036] In one embodiment, the motor drive detection circuit 2 includes a thyristor SCR1, a triode Q5, a field effect transistor Q1, a field effect transistor Q2, a field effect transistor Q3, a field effect transistor Q4, a motor M, a resistor R1, a diode D1, a diode D2, a capacitor C3, a capacitor C4, and an operational amplifier U1;

[0037] One end of the motor M is respectively connected to the source electrode of the field effect transistor Q1, the drain electrode of the field effect transistor Q3, one end of the capacitor C3, and the positive electrode of the diode D1. The drain electrode of the field effect transistor Q1 is respectively connected to the emitter of the triode Q5, the third pin of the thyristor SCR1, and the drain electrode of the field effect transistor Q2. The base of the triode Q5 is connected to the second pin of the CPU processor 1. The collector of the triode Q5 is connected to the power supply VCC. The first pin of the thyristor SCR1 is connected to the energy storage circuit 3. The second pin of the thyristor SCR1 is connected to the first pin of the CPU processor 1. The source electrode of the field effect transistor Q3 is connected to the other end of the capacitor C3 and grounded. The other end of the motor M is respectively connected to one end of the resistor R1 and the non-inverting input terminal of the operational amplifier U1. The other end of the resistor R1 is respectively connected to the source electrode of the field effect transistor Q2, the drain electrode of the field effect transistor Q4, one end of the capacitor C4, the positive electrode of the diode D2, and the inverting input terminal of the operational amplifier U1. The output terminal of the operational amplifier U1 is connected to the fifth pin of the CPU processor 1. The other end of the capacitor C4 is connected to the source electrode of the field effect transistor Q4 and grounded. The negative electrode of the diode D2 is respectively connected to the negative electrode of the diode D1 and the energy storage circuit 3.

[0038] In one embodiment, the energy storage circuit 3 includes a field effect transistor Q6, a field effect transistor Q7, a field effect transistor Q8, a field effect transistor Q9, an inductor L1, an inductor L2, a resistor R2, and an operational amplifier U2;

[0039] The gate of the field effect transistor Q6 is connected to the third pin of the CPU processor 1. The drain of the field effect transistor Q6 is respectively connected to the first pin of the thyristor SCR1, the source of the field effect transistor Q9, and one end of the inductor L2. The source of the field effect transistor Q6 is respectively connected to the negative electrode of the diode D1, the negative electrode of the diode D2, one end of the resistor R2, and the negative phase input terminal of the operational amplifier U2. The positive phase input terminal of the operational amplifier U2 is respectively connected to the other end of the resistor R2, the drain of the field effect transistor Q8, and one end of the inductor L1. The other end of the inductor L1 is respectively connected to the drain of the field effect transistor Q9 and the drain of the field effect transistor Q7. The source of the field effect transistor Q7 is respectively connected to the source of the field effect transistor Q8 and the other end of the inductor L2. The output terminal of the operational amplifier U2 is connected to the fourth pin of the CPU processor 1.

[0040] In one embodiment, the field effect transistors Q1 to Q4 and the field effect transistors Q6 to Q9 are all N-channel field effect transistors.

[0041] In one embodiment, when the motor M is operating normally, the triode Q5 is turned on and the thyristor SCR1 is turned off. At this time, no current passes through the inductor.

[0042] In one embodiment, when the motor M stops or decelerates, the triode Q5 and the field effect transistor Q4 are turned off, and at the same time, the thyristor SCR1 and the field effect transistor Q7 are turned on, so that the inductors L1 and L2 are in a series state. At this time, current flows into the inductor for energy storage.

[0043] To facilitate the understanding of the above technical solutions of the present invention, the working principle or operation mode of the present invention in the actual process will be described in detail below.

[0044] In actual application, when the motor M is operating normally, the triode Q5 is turned on and the power supply is provided. The thyristor SCR1 is turned off. At this time, the electric drive detection circuit 2 is equivalent to a conventional motor drive circuit, and no current passes through the inductor. The current flow is as Figure 3 shown;

[0045] When the motor M needs to stop or decelerate, the triode Q5 (turning off the power supply) and the field effect transistor Q4 are turned off, and the thyristor SCR1 and the field effect transistor Q7 are turned on, so that the inductors are in a series state. The original current of the motor coil flows into the inductor for energy storage. The current flow is as Figure 4 shown. At this time, the current of the motor coil and the induced current brought by the rotation of the motor M both flow into the inductor. The overall current shows a downward trend, indicating that the motor brakes and decelerates, as Figure 5As shown, after the energy storage circuit 3 is connected, the current of the motor M drops rapidly, and the corresponding inductor current rises rapidly. The energy is transferred from the motor M to the inductor. After the motor current and the inductor current are measured to be the same through the sampling resistor R1 and the resistor R2, the thyristor SCR1 is turned off, and the field effect transistor Q6 is turned on, so that the energy storage circuit 3 continues to store energy, and the motor M finally stops.

[0046] When the motor M needs to start or accelerate, the field effect transistors Q1, Q4 and the thyristor SCR1 are turned on, and at the same time, the field effect transistors Q6, Q7, Q8 and Q9 are turned off. After the energy storage circuit 3 connects the inductors in parallel, the stored energy is provided to the motor drive detection circuit 2. At this time, the current of the parallel inductors is several times the current during storage, so that the motor M obtains a large acceleration. As Figure 6 shown, when the resistor R1 detects that the motor current reaches the set value, the triode Q5 is turned on for power supply, and the motor drive detection circuit 2 starts to operate normally.

[0047] In summary, by means of the above technical solutions of the present invention, the motor braking circuit provided by the present invention uses an inductor to absorb and store energy. When the motor stops running, the energy is temporarily stored in the inductor, and the stored energy is released in the next operating cycle to start the motor. This method not only avoids energy waste and overheating, but also can significantly extend the service life of the battery and reduce the temperature rise of the equipment. Compared with the traditional capacitive energy storage scheme, the motor braking circuit provided by the present invention has a higher power density and a smaller volume when using an inductor, which further improves the overall performance and service life of the equipment. In addition, this design helps to improve the energy efficiency and environmental adaptability of the equipment, making the ventilator more reliable and durable.

[0048] In the present invention, unless otherwise clearly defined and limited, terms such as "installation", "setting", "connection", "fixation", "swivel connection" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. It can be the internal communication of two components or the interaction relationship between two components. Unless otherwise clearly defined, for those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0049] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A motor braking circuit applied to a ventilator, characterized in that, It includes a CPU processor, a motor drive detection circuit and an energy storage circuit; The output end of the CPU processor is electrically connected to the input end of the motor drive detection circuit, the output end of the motor drive detection circuit is electrically connected to the input end of the energy storage circuit, and the output end of the energy storage circuit is electrically connected to the input end of the CPU processor.

2. The motor braking circuit for a ventilator according to claim 1, characterized in that, The motor drive detection circuit includes a thyristor SCR1, a triode Q5, a field effect transistor Q1, a field effect transistor Q2, a field effect transistor Q3, a field effect transistor Q4, a motor M, a resistor R1, a diode D1, a diode D2, a capacitor C3, a capacitor C4 and an operational amplifier U1; One end of the motor M is respectively connected to the source electrode of the field effect transistor Q1, the drain electrode of the field effect transistor Q3, one end of the capacitor C3 and the positive electrode of the diode D1. The drain electrode of the field effect transistor Q1 is respectively connected to the emitter of the triode Q5, the third pin of the thyristor SCR1 and the drain electrode of the field effect transistor Q2. The base of the triode Q5 is connected to the second pin of the CPU processor. The collector of the triode Q5 is connected to the power supply VCC. The first pin of the thyristor SCR1 is connected to the energy storage circuit. The second pin of the thyristor SCR1 is connected to the first pin of the CPU processor. The source electrode of the field effect transistor Q3 is connected to the other end of the capacitor C3 and grounded. The other end of the motor M is respectively connected to one end of the resistor R1 and the non-inverting input terminal of the operational amplifier U1. The other end of the resistor R1 is respectively connected to the source electrode of the field effect transistor Q2, the drain electrode of the field effect transistor Q4, one end of the capacitor C4, the positive electrode of the diode D2 and the inverting input terminal of the operational amplifier U1. The output terminal of the operational amplifier U1 is connected to the fifth pin of the CPU processor. The other end of the capacitor C4 is connected to the source electrode of the field effect transistor Q4 and grounded. The negative electrode of the diode D2 is respectively connected to the negative electrode of the diode D1 and the energy storage circuit.

3. The motor braking circuit for a ventilator according to claim 2, wherein, The energy storage circuit includes a field effect transistor Q6, a field effect transistor Q7, a field effect transistor Q8, a field effect transistor Q9, an inductor L1, an inductor L2, a resistor R2 and an operational amplifier U2; The gate of the field effect transistor Q6 is connected to the third pin of the CPU processor. The drain of the field effect transistor Q6 is respectively connected to the first pin of the thyristor SCR1, the source of the field effect transistor Q9, and one end of the inductor L2. The source of the field effect transistor Q6 is respectively connected to the negative electrode of the diode D1, the negative electrode of the diode D2, one end of the resistor R2, and the negative phase input terminal of the operational amplifier U2. The positive phase input terminal of the operational amplifier U2 is respectively connected to the other end of the resistor R2, the drain of the field effect transistor Q8, and one end of the inductor L1. The other end of the inductor L1 is respectively connected to the drain of the field effect transistor Q9 and the drain of the field effect transistor Q7. The source of the field effect transistor Q7 is respectively connected to the source of the field effect transistor Q8 and the other end of the inductor L2. The output terminal of the operational amplifier U2 is connected to the fourth pin of the CPU processor.

4. The motor braking circuit for a ventilator according to claim 3, characterized in that, The field effect transistors Q1 to Q4 and the field effect transistors Q6 to Q9 are all N-channel field effect transistors.

5. The motor braking circuit for a ventilator according to claim 4, characterized in that, When the motor M is working normally, the triode Q5 is turned on and the thyristor SCR1 is turned off. At this time, no current passes through the inductor.

6. The motor braking circuit for a ventilator according to claim 5, characterized in that, When the motor M stops or decelerates, the triode Q5 and the field effect transistor Q4 are turned off. At the same time, the thyristor SCR1 and the field effect transistor Q7 are turned on, so that the inductors L1 and L2 are in a series state. At this time, current flows into the inductor for energy storage.

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