CN114553073A - Control circuit of direct current brush motor and electric sickbed - Google Patents
Control circuit of direct current brush motor and electric sickbed Download PDFInfo
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- CN114553073A CN114553073A CN202210203509.0A CN202210203509A CN114553073A CN 114553073 A CN114553073 A CN 114553073A CN 202210203509 A CN202210203509 A CN 202210203509A CN 114553073 A CN114553073 A CN 114553073A
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- 238000004146 energy storage Methods 0.000 claims abstract description 48
- 239000003990 capacitor Substances 0.000 claims description 18
- 229910044991 metal oxide Inorganic materials 0.000 claims description 3
- 150000004706 metal oxides Chemical class 0.000 claims description 3
- 239000004065 semiconductor Substances 0.000 claims description 3
- 230000005669 field effect Effects 0.000 claims description 2
- 238000004804 winding Methods 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- 230000008569 process Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000000474 nursing effect Effects 0.000 description 3
- 230000032683 aging Effects 0.000 description 2
- 230000002457 bidirectional effect Effects 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 201000010099 disease Diseases 0.000 description 1
- 208000037265 diseases, disorders, signs and symptoms Diseases 0.000 description 1
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- 230000006872 improvement Effects 0.000 description 1
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P7/00—Arrangements for regulating or controlling the speed or torque of electric DC motors
- H02P7/06—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual DC dynamo-electric motor by varying field or armature current
- H02P7/18—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual DC dynamo-electric motor by varying field or armature current by master control with auxiliary power
- H02P7/24—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual DC dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices
- H02P7/28—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual DC dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices using semiconductor devices
- H02P7/285—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual DC dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices using semiconductor devices controlling armature supply only
- H02P7/292—Arrangements for regulating or controlling the speed or torque of electric DC motors for regulating or controlling an individual DC dynamo-electric motor by varying field or armature current by master control with auxiliary power using discharge tubes or semiconductor devices using semiconductor devices controlling armature supply only using static converters, e.g. AC to DC
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/08—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
- H02M1/088—Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters for the simultaneous control of series or parallel connected semiconductor devices
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M7/00—Conversion of AC power input into DC power output; Conversion of DC power input into AC power output
- H02M7/02—Conversion of AC power input into DC power output without possibility of reversal
- H02M7/04—Conversion of AC power input into DC power output without possibility of reversal by static converters
- H02M7/12—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M7/21—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M7/217—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M7/219—Conversion of AC power input into DC power output without possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only in a bridge configuration
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Control Of Direct Current Motors (AREA)
Abstract
The control circuit comprises an H-bridge drive circuit connected with the direct-current brush motor, wherein the H-bridge drive circuit comprises a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, the control end of the second switch tube is connected with a first pull-up circuit, the control end of the third switch tube is connected with a second pull-up circuit, and the first pull-up circuit and the second pull-up circuit are respectively connected with a first energy storage element and a second energy storage element; under the condition that the first power end is not powered, the first energy storage element and the second energy storage element respectively supply power to the first pull-up circuit and the second pull-up circuit so as to enable the second switching tube and the third switching tube to be conducted, two ends of the direct-current brush motor are in short circuit, the hospital bed posture adjusting operation and the hospital bed posture maintaining operation can be achieved under the state that external power or internal power is available, and the hospital bed posture is maintained for a long time when external power is not available and the internal power cannot supply power.
Description
Technical Field
The application belongs to the technical field of medical equipment, and particularly relates to a control circuit of a direct current brush motor and an electric sickbed.
Background
With the improvement of living standard of people and the progress of medical care industry, the aging of population becomes a social problem worldwide. The common problem of the aged population aging countries is to use the social health care mode to solve the problems of family care and nursing of the aged who are weak and bedridden or cannot take care of life due to diseases. The social population has a large number of patients lying in bed for a long time due to various reasons, and the patients are mainly nursed by families, the nursing cost is high, the labor intensity is high, and the nursing conditions need to be improved. Accordingly, the demand for electric hospital beds is increasing.
At present, electric sickbeds on the market basically use an electric push rod as a driving device for changing the posture of the sickbed, and the safety of the electric sickbed is considered to be a priority. However, since the power assembly of the electric push rod is a brush motor, the rotating torque of the brush motor is extremely small under the condition of no driving, which results in the reduction of the locking force of the electric push rod, and the long-time locking force cannot be provided under the conditions of low electric quantity and no power supply, so that the current posture of the hospital bed cannot be maintained.
Disclosure of Invention
The purpose of the embodiment of the application is to provide a control circuit of a direct current brush motor and an electric sickbed, so as to solve the problem that the electric sickbed in the prior art cannot provide long-time locking force.
In order to solve the technical problem, the present application is implemented as follows:
in a first aspect, a control circuit of a dc brushed motor is provided, which includes an H-bridge driving circuit connected to the dc brushed motor, where the H-bridge driving circuit includes a first switching tube, a second switching tube, a third switching tube and a fourth switching tube, the first switching tube and the second switching tube form a first half-bridge, the third switching tube and the fourth switching tube form a second half-bridge, and the first half-bridge and the second half-bridge respectively control on and off of two ends of the dc brushed motor;
the first end of the first switch tube and the first end of the fourth switch tube are respectively connected with a first power supply end, the second end of the second switch tube and the second end of the third switch tube are respectively connected with a first common ground, one end of the direct current brush motor is respectively connected with the second end of the first switch tube and the first end of the second switch tube, and the other end of the direct current brush motor is respectively connected with the second end of the fourth switch tube and the first end of the third switch tube; the control end of the first switch tube is connected with the first control driving end, the first control driving end is used for receiving a control signal of the first switch tube, the control end of the fourth switch tube is connected with the third control driving end, and the third control driving end is used for receiving a control signal of the fourth switch tube;
the control end of the second switching tube is connected with a first pull-up circuit, the control end of the third switching tube is connected with a second pull-up circuit, and the first pull-up circuit and the second pull-up circuit are respectively connected with a first energy storage element and a second energy storage element; under the condition that the first power end is not powered, the first energy storage element and the second energy storage element respectively supply power to the first pull-up circuit and the second pull-up circuit, so that the second switching tube and the third switching tube are conducted, and two ends of the direct-current brush motor are in short circuit.
In a second aspect, an electric hospital bed is provided, which comprises a dc brush motor and a control circuit of the dc brush motor, wherein the dc brush motor is used as a driving device for changing the posture of the hospital bed.
According to the embodiment of the application, the control end of the second switch tube in the H-bridge drive circuit of the direct-current brush motor is connected with the first pull-up circuit, the control end of the third switch tube in the H-bridge drive circuit is connected with the second pull-up circuit, the first pull-up circuit and the second pull-up circuit are respectively connected with the first energy storage element and the second energy storage element, and then the first pull-up circuit and the second pull-up circuit are respectively supplied with power through the first energy storage element and the second energy storage element, so that the second switch tube and the third switch tube are conducted, two ends of the direct-current brush motor are in short circuit, the hospital bed posture adjusting operation and the hospital bed posture maintaining can be realized under the state of having external power supply or internal power supply, and the hospital bed posture can be maintained for a long time when no external power supply exists and the internal power supply cannot supply can supply.
Drawings
Fig. 1 is a schematic structural diagram of an H-bridge driving circuit according to an embodiment of the present disclosure;
fig. 2 is a schematic structural diagram of a control circuit of a dc brush motor according to an embodiment of the present application.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The control circuit of the direct-current brush motor in the embodiment of the application comprises an H-bridge drive circuit connected with the direct-current brush motor, wherein the H-bridge drive circuit comprises a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, the first switch tube and the second switch tube form a first half-bridge, the third switch tube and the fourth switch tube form a second half-bridge, and the first half-bridge and the second half-bridge respectively control the on-off of two ends of the direct-current brush motor;
the first end of the first switch tube and the first end of the fourth switch tube are respectively connected with a first power supply end, the second end of the second switch tube and the second end of the third switch tube are respectively connected with a first common ground, one end of the direct current brush motor is respectively connected with the second end of the first switch tube and the first end of the second switch tube, and the other end of the direct current brush motor is respectively connected with the second end of the fourth switch tube and the first end of the third switch tube; the control end of the first switch tube is connected with the first control driving end, the first control driving end is used for receiving a control signal of the first switch tube, the control end of the fourth switch tube is connected with the third control driving end, and the third control driving end is used for receiving a control signal of the fourth switch tube;
the control end of the second switching tube is connected with a first pull-up circuit, the control end of the third switching tube is connected with a second pull-up circuit, and the first pull-up circuit and the second pull-up circuit are respectively connected with a first energy storage element and a second energy storage element; under the condition that the first power end is not powered, the first energy storage element and the second energy storage element respectively supply power to the first pull-up circuit and the second pull-up circuit, so that the second switching tube and the third switching tube are conducted, and two ends of the direct-current brush motor are in short circuit.
Further, a first diode is arranged between the first energy storage element and the first power supply end, and a second diode is arranged between the second energy storage element and the first power supply end.
Furthermore, a control end of the second switch tube is connected with a first end of a fifth switch tube, a second end of the fifth switch tube is connected with a second control driving end, the control end of the fifth switch tube is connected with a second power supply end, and the second control driving end is used for receiving a control signal of the second switch tube; the control end of the third switching tube is connected with the first end of a sixth switching tube, the second end of the sixth switching tube is connected with a fourth control driving end, the control end of the sixth switching tube is connected with a third power supply end, and the fourth control driving end is used for receiving a control signal of the third switching tube;
under the condition that power is supplied to the second power supply end and the third power supply end, a conducting voltage is provided for the second control driving end and the fourth control driving end, a closing voltage is provided for the first control driving end and the third control driving end, so that the fifth switching tube and the sixth switching tube are conducted, the second switching tube and the third switching tube are conducted, and the first switching tube and the fourth switching tube are not conducted.
The second switch tube and the third switch tube are both Metal Oxide Semiconductor Field Effect Transistors (MOSFETs), the first ends of the second switch tube and the third switch tube are both drain electrodes, the second ends of the second switch tube and the third switch tube are both source electrodes, and the control ends of the second switch tube and the third switch tube are both grid electrodes. The first energy storage element and the second energy storage element are respectively a first energy storage capacitor and a second energy storage capacitor.
The following describes in detail a control circuit of a dc brushed motor according to an embodiment of the present application with reference to the accompanying drawings.
The basic components of a dc brushed motor include: the stator consists of a permanent magnet or an electromagnetic winding and is used for generating a fixed magnetic field around the rotor; the rotor (also called armature) is made up of one or more windings. When the windings are energized, a magnetic field is generated for driving the rotor to rotate. Unlike other motor types, dc brushed motors do not require a controller to switch the direction of the current in the electrode windings, but rather mechanically accomplish the commutation of the current in the dc brushed motor windings. A rotating shaft of the direct current brush motor is provided with a piece-separating copper sleeve which is called a commutator. As the motor rotates, the carbon brushes slide along the commutator and contact different segments of the commutator. These segments are connected to different rotor windings, so that when power is applied through the brushes of the machine, a dynamic magnetic field is generated inside the machine.
Specifically, current flows into the left electric brush along the positive pole of the direct-current power supply, the electric brush is in contact with the commutator, the current flows into the coil through the commutator (also called a commutator segment, and the motor is provided with a left commutator segment and a right commutator segment) in contact with the electric brush, the current of the coil flows back to the negative pole of the direct-current power supply through the right commutator segment and the right electric brush, a closed loop is formed, and the current forms a magnetic field on the rotor. The rotor magnetic field will produce opposite magnetic poles attraction with the stator magnetic field, and its acting force will make the rotor rotate. In the process of rotor rotation, the commutator and the electric brush can continuously excite the winding according to a certain connection sequence, and an alternating magnetic field is generated to enable the rotor to maintain rotation. When the brushes are short-circuited in a state where the brushes are turned off and the coil (rotor) is still rotating in the counterclockwise direction, a rotational force opposite to the current rotational direction is generated, and a braking action to stop the original rotation is performed, which is called "short-circuit braking". The force to stop the rotation increases with the increase of the current of the brushed direct current motor, so that when the rotating speed of the brushed direct current motor is higher, stronger braking is applied; when the rotation speed of the brushed dc motor is reduced, the braking will be weakened, and when the rotation of the brushed dc motor stops, the braking will become zero.
Bidirectional driving of a dc brushed motor needs to be achieved by an H-bridge drive circuit, which is famous for its appearance in a schematic diagram, which enables the current in the motor winding to move in two directions. To understand this, the H-bridge drive circuit must be divided into two parts, or half-bridges, as shown in fig. 1, Q1 and Q2 forming one half-bridge and Q3 and Q4 forming the other half-bridge. Each half bridge can control the conduction and the disconnection of one end of the BDC of the DC brush motor to enable the potential of the BDC to be supply voltage or ground potential. In the case of a non-power supply locking motor, because two ends of the motor cannot be directly short-circuited, the Q2 and the Q3 are controlled to be simultaneously conducted and short-circuited to the ground, and the corresponding conducting voltage is provided at the grid ends when the Q2 and the Q3 are conducted, so that an energy storage element is required as a supply source of the conducting voltage. In order to prolong the conduction time, the selection of the type of the lower tube needs to be low in leakage current, and the MOS tube is a voltage control device and does not need current in an ideal state when being conducted.
Under the condition of power supply, one conducting MOS (metal oxide semiconductor) transistor voltage needs to be supplied to the control2 and the control4 to conduct the Q2 and the Q3, and the motor is locked; a closed MOS tube voltage is provided for the control1 and the control3, so that the Q1 and the Q4 are not conducted, and the condition that the upper tube and the lower tube are conducted simultaneously is prevented. In this circuit mode, when no power is supplied, Q2 and Q3 are not conductive, and the two ends of the motor cannot be short-circuited, so that locking cannot be achieved. The problem that the grid ends of the Q2 and the Q3 are disconnected with the control driving ends, control2 and control4 when no power is supplied needs to be solved.
In addition, the circuits connected with R3, R4, R5 and R6 in fig. 1 are protection circuits in the equivalent control end driving circuit, and the functions of the protection circuits are to ensure that the gates and the sources of the upper and lower tubes are at the same potential in an idle state, so as to prevent the upper and lower tubes of the H bridge from being simultaneously conducted and damaging the H bridge.
As shown in fig. 2, a control circuit of a dc brush motor provided for an embodiment of the present application includes an H-bridge driving circuit connected to a dc brush motor BDC, where the H-bridge driving circuit includes a first switching tube Q1, a second switching tube Q2, a third switching tube Q3, and a fourth switching tube Q4, the first switching tube Q1 and the second switching tube Q2 form a first half-bridge, the third switching tube Q3 and the fourth switching tube Q4 form a second half-bridge, and the first half-bridge and the second half-bridge respectively control on and off of two ends of the dc brush motor BDC.
The first end of the first switch tube Q1 and the first end of the fourth switch tube Q4 are respectively connected with a first power supply terminal VCC, the second end of the second switch tube Q2 and the second end of the third switch tube Q3 are respectively connected with a first common ground GND, one end of the dc brush motor BDC is respectively connected with the second end of the first switch tube Q1 and the first end of the second switch tube Q2, and the other end of the dc brush motor BDC is respectively connected with the second end of the fourth switch tube Q4 and the first end of the third switch tube Q3; the control end of the first switching tube Q1 is connected with a first control drive end control1, the first control drive end control1 is used for receiving a control signal of the first switching tube Q1, the control end of the fourth switching tube Q4 is connected with a third control drive end control3, and the third control drive end control3 is used for receiving a control signal of the fourth switching tube Q4.
The control end of the second switching tube Q2 is connected with a first pull-up circuit, the control end of the third switching tube Q3 is connected with a second pull-up circuit, and the first pull-up circuit and the second pull-up circuit are respectively connected with a first energy storage capacitor C1 and a second energy storage capacitor C2; under the condition that the first power supply end VCC is not powered, the first energy storage capacitor C1 and the second energy storage capacitor C2 respectively supply power to the first pull-up circuit and the second pull-up circuit, so that the second switching tube Q2 and the third switching tube Q3 are conducted, and two ends of the DC brush motor BDC are in short circuit. A diode D1 is arranged between the first energy storage capacitor C1 and the first power supply end, and a diode D2 is arranged between the second energy storage capacitor C2 and the first power supply end.
The second switching tube Q2 and the third switching tube Q3 are both MOSFETs, the first ends of the second switching tube Q2 and the third switching tube Q3 are both drains, the second ends of the second switching tube Q2 and the third switching tube Q3 are both sources, and the control ends of the second switching tube Q2 and the third switching tube Q3 are both gates.
Specifically, to lock the motor, the gate terminals of Q2 and Q3 need to be given a corresponding bias voltage to turn on Q2 and Q3 when no power is supplied. Pull-up circuits are added at the gate terminals of Q2 and Q3. After a power supply end VCC is closed, the energy storage capacitors C1 and C2 supply power to the pull-up circuit, a conduction voltage VCC _ g is provided for grid ends of Q2 and Q3, so that Q2 and Q3 are conducted, two ends of the brush motor are in short circuit, and the motor is locked. Diodes D1 and D2 are added between the power supply end and the energy storage capacitors C1 and C2 to stop the leakage of current and maintain the voltage of the energy storage capacitors.
Further, a control terminal of the second switching tube Q2 is connected to a first terminal of the fifth switching tube Q5, a second terminal of the fifth switching tube Q5 is connected to a second control driving terminal control2, a control terminal of the fifth switching tube Q5 is connected to a second power terminal VCC _ t, and the second control driving terminal control2 is configured to receive a control signal of the second switching tube Q2; the control end of the third switching tube Q3 is connected to the first end of the sixth switching tube Q6, the second end of the sixth switching tube Q6 is connected to the fourth control driving end control4, the control end of the sixth switching tube Q6 is connected to the third power end VCC _ t, and the fourth control driving end control4 is configured to receive a control signal of the third switching tube Q3.
Under the condition that power is supplied to the second power supply terminal VCC _ t and the third power supply terminal VCC _ t, a turn-on voltage is supplied to the second control driving terminal control2 and the fourth control driving terminal control4, a closing voltage is supplied to the first control driving terminal control1 and the third control driving terminal control3, so that the fifth switching tube Q5 and the sixth switching tube Q6 are turned on, the second switching tube Q2 and the third switching tube Q3 are turned on, and the first switching tube Q1 and the fourth switching tube Q4 are turned off.
Specifically, mos transistors Q5 and Q6 are added as switches at the control terminal, and VCC _ t is a power supply for conducting Q5 and Q6 under the condition of power supply. When power is supplied, Q5 and Q6 are conducted, control signals can be transmitted normally, and the voltages of the grid ends of Q2 and Q3 can be pulled down through the pull-down circuit when the control signals are in an idle state, so that Q2 and Q3 are kept not conducted; when no power is supplied, Q5 and Q6 are not conductive, and Q2 and Q3 are in high-impedance state.
According to the embodiment of the application, the control end of the second switch tube in the H-bridge drive circuit of the direct-current brush motor is connected with the first pull-up circuit, the control end of the third switch tube in the H-bridge drive circuit is connected with the second pull-up circuit, the first pull-up circuit and the second pull-up circuit are respectively connected with the first energy storage element and the second energy storage element, and then the first pull-up circuit and the second pull-up circuit are respectively supplied with power through the first energy storage element and the second energy storage element, so that the second switch tube and the third switch tube are conducted, two ends of the direct-current brush motor are in short circuit, the hospital bed posture adjusting operation and the hospital bed posture maintaining can be realized under the state of having external power supply or internal power supply, and the hospital bed posture can be maintained for a long time when no external power supply exists and the internal power supply cannot supply can supply.
In the embodiment of the application, the current consumption mainly comprises the leakage current of the diode, the leakage current of the lower tube of the H-bridge and the mos tube of the switch and the self-discharge of the energy storage capacitor. In order to obtain the holding time of the energy storage capacitor, the leakage current of the capacitor, the reverse leakage current of the diode, coulomb electrons required by the gate drive conduction of the H-bridge lower tube and the drain-source leakage current of the switch mos tube need to be obtained. The conduction condition of the mos tube under the H-bridge is that the grid electrode and the source electrode meet a certain voltage difference, and the condition for forming the voltage difference is that the grid electrode of the mos tube obtains enough coulomb electrons. Therefore, the total coulomb electrons minus the coulomb electrons obtained by the mos tube gate under the H-bridge are the electric energy consumed by the H-bridge under the tube. In order to control the time for maintaining the motor locked during power failure, it is necessary to select a device with a proper leakage current and a capacitor with a proper capacity.
Specifically, the diode has a reverse leakage current of 3pA at a reverse voltage of 20V. When the power supply is 18V, the leakage current of the film capacitor is 60 pA. The grid electrode of the H-bridge lower tube needs 6nC, Vgs (th) and the conducting voltage is 1.5V. When the direct-current voltage of the drain-source electrode is 20V, the maximum reverse leakage current of the switching tube is 10 nA. If the circuit is built by using the device, the theoretical shortest time is 4.5 hours, and if the locked state of more than 72 hours is to be kept, the capacitance capacity can be increased to more than 160 uF.
The embodiment of the application also provides an electric sickbed, which comprises a direct current brush motor and a control circuit of the direct current brush motor as shown in 2, wherein the direct current brush motor is used as a driving device for changing the posture of the sickbed.
When two ends of the electrode of the direct current brush motor are in short circuit, the motor can be locked. In the application of the electric sickbed, the push rod motor is required to be retractable forwards and backwards, so that the push rod motor is required to be driven by a bidirectional driving circuit, and the motor can be locked under the conditions of power supply and no power supply.
Specifically, the posture adjustment operation of the hospital bed (driving of the motor inside the electric push rod) is realized in a state of having an external power supply or an internal power supply. Under the state of having external power supply or internal power supply, the sick bed gesture (the locking of the motor in the electric putter) is maintained when there is no gesture adjustment operating condition. When no external power supply is available and the internal power supply is exhausted or fails and cannot supply power, the posture of the hospital bed is maintained (the locking of the motor inside the electric push rod). When the external end power supply, the internal battery and the control cable (without power supply) are disconnected, the motor is only kept connected with the control system, and the motor locking for more than 72 hours can be realized.
It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
While the present embodiments have been described with reference to the accompanying drawings, it is to be understood that the invention is not limited to the precise embodiments described above, which are meant to be illustrative and not restrictive, and that various changes may be made therein by those skilled in the art without departing from the spirit and scope of the invention as defined by the appended claims.
Claims (6)
1. A control circuit of a direct-current brush motor is characterized by comprising an H-bridge drive circuit connected with the direct-current brush motor, wherein the H-bridge drive circuit comprises a first switch tube, a second switch tube, a third switch tube and a fourth switch tube, the first switch tube and the second switch tube form a first half-bridge, the third switch tube and the fourth switch tube form a second half-bridge, and the first half-bridge and the second half-bridge respectively control the on-off of two ends of the direct-current brush motor;
the first end of the first switch tube and the first end of the fourth switch tube are respectively connected with a first power supply end, the second end of the second switch tube and the second end of the third switch tube are respectively connected with a first common ground, one end of the direct current brush motor is respectively connected with the second end of the first switch tube and the first end of the second switch tube, and the other end of the direct current brush motor is respectively connected with the second end of the fourth switch tube and the first end of the third switch tube; the control end of the first switch tube is connected with a first control driving end, the first control driving end is used for receiving a control signal of the first switch tube, the control end of the fourth switch tube is connected with a third control driving end, and the third control driving end is used for receiving the control signal of the fourth switch tube;
the control end of the second switching tube is connected with a first pull-up circuit, the control end of the third switching tube is connected with a second pull-up circuit, and the first pull-up circuit and the second pull-up circuit are respectively connected with a first energy storage element and a second energy storage element; under the condition that the first power end is not powered, the first energy storage element and the second energy storage element respectively supply power to the first pull-up circuit and the second pull-up circuit, so that the second switching tube and the third switching tube are conducted, and two ends of the direct-current brush motor are in short circuit.
2. The control circuit according to claim 1, wherein the control terminal of the second switch tube is connected to a first terminal of a fifth switch tube, a second terminal of the fifth switch tube is connected to a second control driving terminal, the control terminal of the fifth switch tube is connected to a second power supply terminal, and the second control driving terminal is configured to receive a control signal of the second switch tube; the control end of the third switching tube is connected with the first end of a sixth switching tube, the second end of the sixth switching tube is connected with a fourth control driving end, the control end of the sixth switching tube is connected with a third power supply end, and the fourth control driving end is used for receiving a control signal of the third switching tube;
under the condition that power is supplied to the second power supply end and the third power supply end, a conducting voltage is provided for the second control driving end and the fourth control driving end, a closing voltage is provided for the first control driving end and the third control driving end, so that the fifth switching tube and the sixth switching tube are conducted, the second switching tube and the third switching tube are conducted, and the first switching tube and the fourth switching tube are not conducted.
3. The control circuit of claim 1, wherein the second switch tube and the third switch tube are both Metal Oxide Semiconductor Field Effect Transistors (MOSFETs), first ends of the second switch tube and the third switch tube are both drain electrodes, second ends of the second switch tube and the third switch tube are both source electrodes, and control ends of the second switch tube and the third switch tube are both gate electrodes.
4. The control circuit according to claim 1, wherein a first diode is disposed between the first energy storage element and the first power supply terminal, and a second diode is disposed between the second energy storage element and the first power supply terminal.
5. The control circuit of claim 4, wherein the first energy storage element and the second energy storage element are a first energy storage capacitor and a second energy storage capacitor, respectively.
6. An electric hospital bed comprising a dc brush motor as a driving means for changing the posture of the hospital bed and a control circuit for the dc brush motor according to any one of claims 1 to 5.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210203509.0A CN114553073A (en) | 2022-03-02 | 2022-03-02 | Control circuit of direct current brush motor and electric sickbed |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210203509.0A CN114553073A (en) | 2022-03-02 | 2022-03-02 | Control circuit of direct current brush motor and electric sickbed |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114553073A true CN114553073A (en) | 2022-05-27 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210203509.0A Pending CN114553073A (en) | 2022-03-02 | 2022-03-02 | Control circuit of direct current brush motor and electric sickbed |
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| CN (1) | CN114553073A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117907688A (en) * | 2023-12-22 | 2024-04-19 | 苏州新云医疗设备有限公司 | Impedance detection circuit, method and electronic device |
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2022
- 2022-03-02 CN CN202210203509.0A patent/CN114553073A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117907688A (en) * | 2023-12-22 | 2024-04-19 | 苏州新云医疗设备有限公司 | Impedance detection circuit, method and electronic device |
| CN117907688B (en) * | 2023-12-22 | 2024-11-22 | 苏州新云医疗设备有限公司 | Impedance detection circuit, method and electronic device |
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