CN216795332U

CN216795332U - Power supply controller of intelligent sphygmomanometer

Info

Publication number: CN216795332U
Application number: CN202123252875.5U
Authority: CN
Inventors: 温承华
Original assignee: Dongguan Wahhing Electrical Appliance Co ltd
Current assignee: Dongguan Wahhing Electrical Appliance Co ltd
Priority date: 2021-12-22
Filing date: 2021-12-22
Publication date: 2022-06-21
Anticipated expiration: 2031-12-22

Abstract

The utility model discloses a power supply controller of an intelligent sphygmomanometer, which comprises a 100-plus 240VAC input module, an EMI filtering module, an input rectifying and filtering module, a PWM converter module, an output rectifying and filtering module, a feedback control module, a PWM control module, an output indicator lamp module and a DC input module, wherein the PWM control module comprises a PWM control chip, and an output overvoltage protection unit, a short-circuit protection unit, an overcurrent protection unit and a power supply overtemperature protection unit which are electrically connected with the PWM control chip; the PWM converter module comprises a transformer, an absorption circuit connected with the transformer, a VCC power supply unit and an MOS tube used as a switch, the VCC power supply unit is connected with a VCC pin of the PWM control chip and an output overvoltage protection unit, the MOS tube is connected with a T1A winding of the transformer, and the overcurrent protection unit is connected with the MOS tube. The utility model has the advantages of output overvoltage protection, short-circuit protection, overcurrent protection and power supply overtemperature protection, ensures the safety of equipment and users and is very safe to use.

Description

Power supply controller of intelligent sphygmomanometer

The technical field is as follows:

the utility model relates to the technical field of electronics, in particular to a power supply controller for an intelligent sphygmomanometer.

The background art comprises the following steps:

with the continuous improvement of the scientific and technical level, social economy is rapidly developed, the living standard of people is greatly improved, the requirements of people on health are higher and higher, and household medical equipment is also popularized more and more.

An intelligent sphygmomanometer is one of common household medical devices, and can judge the functions of the heart and the pressure of external vascular tissues through measured blood pressure information, so that the intelligent sphygmomanometer is widely concerned and applied by people. The intelligent sphygmomanometer is characterized in that a sensor and a control circuit board inside a product are removed, a matched power supply controller is required to be used, the power supply controller not only provides stable electric energy for the intelligent sphygmomanometer, and meanwhile, when the intelligent sphygmomanometer works abnormally, timely protection action is carried out, and driving protection and navigation protection are carried out for users to safely use the intelligent sphygmomanometer.

The current intelligent sphygmomanometer controller uses the design of a common LED-free indicator lamp, and cannot visually feed back to a user when a power supply controller is abnormal.

The current intelligent sphygmomanometer controller has no functions of output overvoltage protection, overcurrent protection and power supply overtemperature protection lamps, and cannot protect the intelligent sphygmomanometer controller better, so that the service life of the intelligent sphygmomanometer controller cannot be effectively guaranteed.

In view of the above, the present inventors propose the following.

The utility model has the following contents:

the utility model aims to overcome the defects of the prior art and provides a power supply controller of an intelligent sphygmomanometer.

In order to solve the technical problems, the utility model adopts the following technical scheme: the power supply controller of the intelligent sphygmomanometer comprises a 100-plus-240 VAC input module, an EMI filtering module, an input rectifying and filtering module, a PWM converter module, an output rectifying and filtering module, a feedback control module, a PWM control module, an output indicator lamp module and a DC input module, wherein the PWM control module comprises a PWM control chip, and an output overvoltage protection unit, a short-circuit protection unit, an overcurrent protection unit and a power supply overtemperature protection unit which are electrically connected with the PWM control chip; the PWM converter module comprises a transformer, an absorption circuit connected with the transformer, a VCC power supply unit and an MOS tube used as a switch, wherein the VCC power supply unit is connected with a VCC pin of the PWM control chip and an output overvoltage protection unit, the MOS tube is connected with a T1A winding of the transformer, and the overcurrent protection unit is connected with the MOS tube.

Furthermore, in the above technical solution, the output overvoltage protection unit includes a triode Q3, a resistor R4, a capacitor C8, and a voltage regulator ZD1, a C-pole of the triode Q3 is connected to a BO pin of the PWM control chip, an E-pole of the triode Q3 is grounded, the capacitor C8 is connected between the E-pole and the C-pole of the triode Q3, a B-pole of the triode Q3 is connected to an anode of the voltage regulator ZD1, and a cathode of the ZD1 is connected to a VCC pin of the PWM control chip after being connected to the resistor R5.

Furthermore, in the above technical solution, the over-current protection unit includes a resistor R8, a resistor R14 connected between the resistor R8 and the G pole of the MOS transistor, a resistor R9 connected between the resistor R8 and the ground, and a resistor R9A, a resistor R9B, and a resistor R9C connected in parallel with the resistor R9 in this order, and the other end of the resistor R9 connected to the ground is further connected to the S pole of the MOS transistor.

Further, in the above technical solution, the power supply over-temperature protection unit includes a thermistor NTC connected to a BO pin of the PWM control chip, and the thermistor NTC is also grounded.

Furthermore, in the above technical solution, the G pole of the MOS transistor is connected to the resistor R7 and the resistor R6 and then connected to the GATE pin of the PWM control chip, the D pole of the MOS transistor is connected to the T1A winding of the transformer, and the S pole of the MOS transistor is connected to the overcurrent protection unit.

Further, in the above technical solution, a resistor R5 is further connected between the VCC power supply unit and the VCC pin of the PWM control chip.

Further, in the above technical solution, the VCC power supply unit includes a T1B winding of the transformer, and a diode D2 and a resistor 13 connected to the T1B winding, the resistor 13 is connected to a resistor R5 and then connected to a VCC pin of the PWM control chip, and the resistor 13 is also connected to a filter capacitor EC2 and then connected to ground.

Further, in the above technical solution, the 100-plus-240 VAC input module includes a 100-plus-240 VAC input terminal, and a fuse F1 and a thermistor NTC1 connected to the AC input terminal.

Further, in the above technical solution, the EMI filter module includes a common mode inductor LF1, a safety X capacitor CX1, and a common mode inductor LF2, which are connected in sequence.

Further, in the above technical solution, the output rectifying and filtering module includes a schottky rectifying diode Q2, an electrolytic capacitor EC3, and an electrolytic capacitor EC 4; the output indicator lamp module comprises an LED and a resistor R23, and the LED and the resistor R23 are connected in series and then connected in parallel with the positive electrode and the negative electrode of the output end.

After adopting the technical scheme, compared with the prior art, the utility model has the following beneficial effects: under various abnormal conditions, the utility model can be used for corresponding protection measures such as output overvoltage protection, short-circuit protection, overcurrent protection and power supply overtemperature protection, thereby ensuring the safety of equipment and users and ensuring the safety of the equipment and the users. The LED indication of the output indicator lamp module is adopted, the working state of the power supply is intuitively fed back to a user, and better use experience is provided for the user.

Description of the drawings:

fig. 1 is a circuit diagram of the present invention.

The specific implementation mode is as follows:

the utility model is further illustrated below with reference to specific embodiments and the accompanying drawings.

Referring to fig. 1, the power supply controller for the intelligent sphygmomanometer comprises a 100-VAC input module 1, an EMI filter module 2, an input rectification filter module 3, a PWM converter module 4, an output rectification filter module 5, a feedback control module 6, a PWM control module 7, an output indicator light module 8 and a DC input module 9.

The 100-plus-240 VAC input module 1 comprises a 100-plus-240 VAC input end 11, and a fuse F1 and a thermistor NTC1 which are connected with the AC input end 11.

The fuse F1 can be immediately fused under the condition of abnormal overload of the power supply, thereby preventing the abnormal condition from further damaging the power supply controller or the intelligent sphygmomanometer and protecting the life and property safety of users. Before the power supply controller is started, the thermistor NTC1 has a large resistance value, surge current at the moment of starting can be effectively reduced, the temperature gradually rises during the work of the power supply controller, and the resistance value of the thermistor NTC1 gradually decreases so as to reduce self heating loss.

The power supply controller of the intelligent sphygmomanometer adopts a C8 socket, and can be used in different countries or regions by only inserting corresponding AC lines into the sockets, so that the intelligent sphygmomanometer is very convenient to use.

The EMI filtering module 2 comprises a common mode inductor LF1, a safety X capacitor CX1 and a common mode inductor LF2 which are connected in sequence. The common mode inductor LF1, the safety X capacitor CX1 and the common mode inductor LF2 form a pi-type filter, so that noise in a power grid and a power supply controller is effectively filtered, and the EMC meets the safety standard when the power supply controller works.

The input rectifying and filtering module 3 comprises a rectifying bridge BD1, an electrolytic capacitor EC1 and a capacitor C1. By using the unidirectional conduction characteristic of the diode and the energy storage principle of the capacitor, alternating current mains supply (AC) is converted into Direct Current (DC) to provide electric energy for the PWM converter module 4. EC1 is 100uF/450V electrolytic capacitor as main energy storage filter capacitor, C1 is 10nF/1kV ceramic capacitor for absorbing high frequency noise and providing purer high voltage DC for PWM converter module 4.

The PWM converter module 4 includes a transformer 41, an absorption circuit 42 connected to the transformer 41, a VCC power supply unit 43, and a MOS 44 as a switch, where the VCC power supply unit 43 is connected to a VCC pin of the PWM control chip 71 and an output overvoltage protection unit 72, the MOS 44 is connected to a T1A winding 411 of the transformer 41, and the overcurrent protection unit 74 is connected to the MOS 44.

The voltage output by the VCC power supply unit 43 is VCC voltage.

The MOS tube 44 is a 7A/650V MOS tube with low conduction loss, and the transformer 41 adopts a PQ2620 magnetic core with low loss of PC 95. The PWM converter module 4 converts the input rectified and filtered high-voltage dc power into a secondary low-voltage ac power, and safely isolates the primary side from the secondary side, which is a core module of the power supply. The resistor R9, the resistor R9A, the resistor R9B and the resistor R9C are connected in parallel, detect the working current of the PWM converter module 4, convert the working current into a voltage signal and transmit the voltage signal to the PWM controller module. The transformer has double insulation levels between the primary and secondary sides, and can effectively prevent electric leakage or electric shock injury caused by misoperation of a user. When a child cuts the outer skin of the DC output line, even if the limb touches the metal part of the DC line, no electric shock injury is caused.

The G pole of the MOS 44 is connected to the resistor R7 and the resistor R6, and then connected to the GATE pin of the PWM control chip 71, the D pole of the MOS 44 is connected to the T1A winding 411 of the transformer 41, and the S pole of the MOS 44 is connected to the overcurrent protection unit 74.

The output rectifying and filtering module 5 comprises a Schottky rectifying diode Q2, an electrolytic capacitor EC3 and an electrolytic capacitor EC 4; the low-voltage alternating current output by the transformer is converted into low-voltage direct current by utilizing the unidirectional conduction characteristic of the diode and the energy storage filtering principle of the capacitor. Q2 adopts the low 20A/100V schottky rectifier diode who switches on the voltage drop, very big promotion the conversion efficiency of power.

The feedback control module 6 comprises an optocoupler U2, a controllable precise voltage-stabilizing source U3 and a voltage division network. The PWM feedback module extracts a voltage signal at an output end through a voltage division network formed by R28, R30 and R31, a reference PIN (PIN1) of a controllable precision voltage-stabilizing source U3 obtains the voltage signal and compares the voltage signal with an internal reference voltage, so that the working state of an output end PIN3 is controlled, the working state of the optocoupler U2 is further controlled, and the optocoupler U2 feeds an output voltage back to the primary side PWM controller module.

The PWM control module 7 includes a PWM control chip 71, and an output overvoltage protection unit 72, a short-circuit protection unit 73, an overcurrent protection unit 74, and a power supply over-temperature protection unit 75 electrically connected to the PWM control chip 71.

The model of the PWM control chip 71 is OB5269BCPA, and OB5269BCPA is a high-performance PWM controller IC, has the advantages of low power consumption, high driving capability, wide working voltage, perfect abnormal protection and the like, and is widely applied to various switching power supply adapters.

The output overvoltage protection unit 72 comprises a triode Q3, a resistor R4, a capacitor C8 and a voltage regulator tube ZD1, wherein the C pole of the triode Q3 is connected with the BO pin of the PWM control chip 71, the E pole of the triode Q3 is grounded, the capacitor C8 is connected between the E pole and the C pole of the triode Q3, the B pole of the triode Q3 is connected with the anode of the voltage regulator tube ZD1, and the cathode of the ZD1 is connected with the VCC pin of the PWM control chip 71 after being connected with the resistor R5.

The output overvoltage protection unit 72 detects an output voltage value by detecting a VCC voltage, when the output voltage is higher than an overvoltage trigger point, the VCC voltage rises and breaks through the voltage regulator tube ZD1, so that the triode Q3 is conducted, the voltage of a BO pin is reduced, the PWM control chip 71 judges that the output voltage is too high from this, the overvoltage protection is triggered, the PWM drive is turned off, and the abnormality of the output overvoltage is prevented from being further aggravated. The output overvoltage protection range designed by the utility model is 13.6-20V.

The PIN2 of the PWM control chip 71 is a PWM feedback signal input PIN (i.e., FB PIN), the PWM feedback signal of the secondary side is transmitted to the FB PIN through the optocoupler U2, and the PWM control chip 71 analyzes the working state of the output end, and further analyzes, calculates and adjusts the duty ratio of the drive waveform of the GATE PIN, so that the power supply forms a stable negative feedback system.

The PIN3 of the PWM control chip 71 is a current detection PIN (i.e., a CS PIN), the overcurrent protection unit 74 includes a resistor R8, a resistor R14 connected between the resistor R8 and the G pole of the MOS transistor 44, a resistor R9 connected between the resistor R8 and the ground, and a resistor R9A, a resistor R9B, and a resistor R9C connected in parallel with the resistor R9 in sequence, and the other end of the resistor R9 connected to the ground is further connected to the S pole of the MOS transistor 44.

The overcurrent protection unit 74 detects the operating current of the PWM converter module and feeds back the operating current to the PWM control chip 71 as a voltage signal. When the output current increases, the working current of the PWM converter also increases, and the voltage of the CS pin increases. When the output current reaches the overcurrent trigger point, the CS pin voltage exceeds the threshold voltage, and the PWM control chip 71 thus determines that the output current is excessive and enters the overcurrent protection mode. The range of the overcurrent protection point designed by the utility model is 4-6A.

The PIN4 of the PWM control chip 71 is ground (i.e., GND PIN), and is connected to the cathode of the electrolytic capacitor in the input rectifying and filtering module, so as to provide 0V potential lines for each module line on the primary side.

The PIN5 of the PWM control chip 71 is a driving PIN (i.e., a GATE PIN), and controls the operating state of the PWM conversion module by connecting the resistor R6, the resistor R7, and the G-pole of the MOS transistor 44. When the GATE pin is at a high potential, the D-S of the MOS tube 44 is conducted, and the current flows from the primary side high-voltage electrolytic capacitor positive electrode through the transformer primary main winding, the D-S of the MOS tube, the resistor R9, the resistor R9A, the resistor R9B, the resistor R9C and then flows back to the primary side high-voltage electrolytic capacitor negative electrode, so that the electric energy of the transformer is converted into magnetic field energy and stored in the process; when the GATE pin is at a low potential, the D-S of the MOS tube is cut off, the secondary side winding of the transformer releases current, and the transformer converts magnetic field energy into electric energy and releases the electric energy in the process.

The power supply over-temperature protection unit 75 includes a thermistor NTC connected to the BO pin of the PWM control chip 71, the thermistor NTC is also grounded, and when the temperature gradually increases, the resistance of the thermistor NTC gradually decreases, and the BO pin of the PWM control chip 71 detects that a set value is reached, the power supply over-temperature protection unit enters an over-temperature protection mode.

And a resistor R5 is also connected between the VCC power supply unit 43 and the VCC pin of the PWM control chip 71.

The VCC power supply unit 43 includes a T1B winding 412 of the transformer 41, and a diode D2 and a resistor 13 connected to the T1B winding 412, the resistor 13 is connected to a resistor R5 and then connected to a VCC pin of the PWM control chip 71, and the resistor 13 is also connected to a filter capacitor EC2 and then connected to ground. The winding of the T1B is rectified and filtered through a diode D2, a resistor R13 and a filter capacitor EC2, and the PWM control chip 71 is supplied with power through a VCC pin.

The short-circuit protection unit 73 comprises a resistor R5 connected with a VCC pin of the PWM control chip 71 and a resistor R8 connected with a CS pin of the PWM control chip 71, when the PWM control chip 71 detects that the voltage of the VCC pin is lower than a threshold value and the voltage of the CS pin is higher than the threshold value, the output positive and negative short circuits are determined, the PWM control chip 71 enters an output short-circuit protection mode, and the PWM control chip 71 is restarted every about 1 second to detect whether the short-circuit condition is removed. When the short circuit is removed, the power supply automatically recovers to normal output.

The output indicator light module 8 comprises an LED and a resistor R23, and the LED and the resistor R23 are connected in series and then connected in parallel with the positive electrode and the negative electrode of the output end. The utility model adopts the LED indication to visually feed back the working state of the power supply to the user, and aims to provide better use experience for the user. When the output voltage is within the specification range, the green LED is lightened, and a user knows that the power supply is started and can work normally. The LED conduction voltage drop is about 3V, the working current of the LED is 9mA calculated according to the current-limiting resistance parameters, the LED luminous intensity is 5000lux, the common indoor illumination is about 500lux, and the LED luminous intensity is far greater than the indoor illumination. Therefore, even in a bright room, the state of the LED can be clearly distinguished, and the operating state of the power supply can be determined.

In conclusion, under various abnormal conditions, the utility model has corresponding protection measures to deal with, such as output overvoltage protection, short-circuit protection, overcurrent protection and power supply overtemperature protection, so that the safety of equipment and users is ensured, and the use is very safe. The LED indication of the output indicator lamp module 8 is adopted, the working state of the power supply is intuitively fed back to a user, and better use experience is provided for the user.

It should be understood that the above description is only exemplary of the present invention, and is not intended to limit the scope of the present invention, which is defined by the appended claims.

Claims

1. Intelligence sphygmomanometer power supply controller, it includes 100 supplyes 240VAC input module (1), EMI filtering module (2), input rectification filtering module (3), PWM converter module (4), output rectification filtering module (5), feedback control module (6), PWM control module (7), output indicator lamp module (8), DC input module (9), its characterized in that:

the PWM control module (7) comprises a PWM control chip (71), and an output overvoltage protection unit (72), a short-circuit protection unit (73), an overcurrent protection unit (74) and a power supply over-temperature protection unit (75) which are electrically connected with the PWM control chip (71);

the PWM converter module (4) comprises a transformer (41), an absorption circuit (42) connected with the transformer (41), a VCC power supply unit (43) and an MOS (metal oxide semiconductor) tube (44) used as a switch, wherein the VCC power supply unit (43) is connected with a VCC pin of a PWM control chip (71) and an output overvoltage protection unit (72), the MOS tube (44) is connected with a T1A winding (411) of the transformer (41), and the overcurrent protection unit (74) is connected with the MOS tube (44).

2. The intelligent sphygmomanometer power supply controller according to claim 1, wherein: the output overvoltage protection unit (72) comprises a triode Q3, a resistor R4, a capacitor C8 and a voltage-regulator tube ZD1, the C pole of the triode Q3 is connected with the BO pin of the PWM control chip (71), the E pole of the triode Q3 is grounded, the capacitor C8 is connected between the E pole and the C pole of the triode Q3, the B pole of the triode Q3 is connected with the anode of the voltage-regulator tube ZD1, and the cathode of the ZD1 is connected with the VCC pin of the PWM control chip (71) after being connected with the resistor R5.

3. The intelligent sphygmomanometer power supply controller according to claim 2, wherein: the overcurrent protection unit (74) comprises a resistor R8, a resistor R14 connected between the resistor R8 and the G pole of the MOS tube (44), a resistor R9 connected between the resistor R8 and the ground, and a resistor R9A, a resistor R9B and a resistor R9C which are sequentially connected in parallel with the resistor R9, wherein the other end of the resistor R9 connected with the ground is also connected with the S pole of the MOS tube (44).

4. The intelligent sphygmomanometer power supply controller according to claim 3, wherein: the power supply over-temperature protection unit (75) comprises a thermistor NTC connected with a BO pin of the PWM control chip (71), and the thermistor NTC is also grounded.

5. The intelligent sphygmomanometer power supply controller according to any one of claims 1-4, wherein: the G pole of the MOS tube (44) is connected with the resistor R7 and the resistor R6 and then connected with the GATE pin of the PWM control chip (71), the D pole of the MOS tube (44) is connected with the T1A winding (411) of the transformer (41), and the S pole of the MOS tube (44) is connected with the overcurrent protection unit (74).

6. The intelligent sphygmomanometer power supply controller according to any one of claims 1 to 4, wherein: and a resistor R5 is also connected between the VCC power supply unit (43) and the VCC pin of the PWM control chip (71).

7. The intelligent sphygmomanometer power supply controller according to any one of claims 1-4, wherein: the VCC power supply unit (43) comprises a T1B winding (412) of a transformer (41), a diode D2 and a resistor 13, wherein the diode D2 and the resistor 13 are connected with the T1B winding (412), the resistor 13 is connected with a resistor R5 and then is connected with a VCC pin of a PWM control chip (71), and the resistor 13 is also connected with a filter capacitor EC2 and then is grounded.

8. The intelligent sphygmomanometer power supply controller according to any one of claims 1 to 4, wherein: the 100-plus-240 VAC input module (1) comprises a 100-plus-240 VAC input end (11), and a fuse F1 and a thermistor NTC1 which are connected with the AC input end (11).

9. The intelligent sphygmomanometer power supply controller according to any one of claims 1 to 4, wherein: the EMI filtering module (2) comprises a common-mode inductor LF1, a safety X capacitor CX1 and a common-mode inductor LF2 which are connected in sequence.

10. The intelligent sphygmomanometer power supply controller according to any one of claims 1 to 4, wherein: the output rectifying and filtering module (5) comprises a Schottky rectifying diode Q2, an electrolytic capacitor EC3 and an electrolytic capacitor EC 4; the output indicator light module (8) comprises an LED and a resistor R23, and the LED and the resistor R23 are connected in series and then connected in parallel with the positive electrode and the negative electrode of the output end.