CN212935542U - Constant current source charging circuit and gas meter with same - Google Patents
Constant current source charging circuit and gas meter with same Download PDFInfo
- Publication number
- CN212935542U CN212935542U CN202021730356.8U CN202021730356U CN212935542U CN 212935542 U CN212935542 U CN 212935542U CN 202021730356 U CN202021730356 U CN 202021730356U CN 212935542 U CN212935542 U CN 212935542U
- Authority
- CN
- China
- Prior art keywords
- circuit
- power supply
- constant current
- resistor
- input
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000007600 charging Methods 0.000 title claims abstract description 96
- 239000003990 capacitor Substances 0.000 claims abstract description 109
- 238000004891 communication Methods 0.000 claims abstract description 109
- 230000000670 limiting effect Effects 0.000 claims abstract description 49
- 238000010277 constant-current charging Methods 0.000 claims abstract description 4
- 238000005070 sampling Methods 0.000 claims description 31
- 238000001514 detection method Methods 0.000 claims description 21
- 238000001914 filtration Methods 0.000 claims description 12
- 238000004146 energy storage Methods 0.000 claims description 10
- 239000003381 stabilizer Substances 0.000 claims description 3
- 238000000034 method Methods 0.000 abstract description 10
- 230000006855 networking Effects 0.000 abstract description 3
- 230000002829 reductive effect Effects 0.000 description 8
- 230000002093 peripheral effect Effects 0.000 description 5
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 229910052744 lithium Inorganic materials 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 230000005669 field effect Effects 0.000 description 3
- 230000003993 interaction Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 229920006395 saturated elastomer Polymers 0.000 description 3
- 230000003068 static effect Effects 0.000 description 3
- 239000000306 component Substances 0.000 description 2
- 230000001276 controlling effect Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 239000008358 core component Substances 0.000 description 1
- 238000010892 electric spark Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Landscapes
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
The embodiment of the utility model discloses constant current source charging circuit and have its gas table relates to thing networking intelligent terminal equipment technical field. The method comprises the following steps: the charging management circuit is electrically connected with the input end of the communication power supply circuit, and the output end of the charging management circuit is connected with the communication module; the charging management circuit comprises a switch control module and a constant current limiting module, wherein the input end of the switch control module is connected with the power supply, the output end of the switch control module is connected with the constant current limiting module, and the output end of the constant current limiting module is electrically connected with the input end of the communication power supply circuit so as to realize the constant current charging of the power supply to the communication power supply circuit. When the farad capacitor of the communication power supply circuit is charged in a constant-current and current-limiting manner, the working voltage of other power utilization elements or functional circuits is basically not influenced, and the normal work of a system and the functional circuits is ensured. Therefore, the circuit can be well suitable for products which have large limitation requirements on external input power and simultaneously have remote communication and multifunctional circuits.
Description
Technical Field
The utility model belongs to the technical field of thing networking intelligent terminal equipment technique and specifically relates to a constant current source charging circuit and have its intelligent gas table is related to.
Background
The intelligent terminal products using the communication technology of the internet of things (including GPRS module, NB-I0T module, Lora-WAN, Bluetooth and the like) as information carriers are continuously developed vigorously along with the continuous increase of market demands.
According to the safety standard requirements, electric sparks or thermal effect energy possibly generated by the interior of products and connecting wires exposed to a potential explosive environment of the products (such as a corrector and a flowmeter) and other electrical products are limited to a level incapable of generating ignition, and the corresponding explosion-proof requirements are met. Therefore, the input power of the power supply of the intelligent gas metering product has a limit requirement.
The intelligent electrical products are not isolated from remote communication data interaction, remote instruction issuing, remote function operation and the like, and the intelligent gas metering products are no exception. The peak current of a communication module (taking NB-IOT as an example) in the explosion-proof product is more than 200 mA, which is far larger than the input current of the explosion-proof product. Meanwhile, intelligent gas metering products have more functions, and some products have three or thirty functional circuits or even more, and the requirements are a challenge to input power supplies. In the existing low-power-consumption product, a power supply part of a communication module is powered by a farad capacitor energy storage element.
At present when low-power consumption product design, with farad capacitor energy storage component for communication module power supply mode, the conventional current-limiting resistance current-limiting that directly uses charges, but this kind of product often is when carrying out remote communication, because the continuous consumption of farad capacitor energy can constantly force more electric currents to charge for it, and the power of total input power is fixed, will lead to microprocessor MCU system and peripheral other function circuit's operating voltage to probably receive the influence like this, finally lead to system and function circuit can not normally work, remote communication also can not normally communicate. Therefore, this charging method is not suitable for products with large limitation on external input power and with telecommunication and multifunctional circuits.
SUMMERY OF THE UTILITY MODEL
In view of this, the embodiment of the utility model provides a constant current source charging circuit and have its intelligent gas table can solve above-mentioned technical problem at least to can be applicable to better in having great restriction requirement to external input power, have remote communication and multifunctional circuit's product simultaneously again.
In order to achieve the above object, a first aspect of the present invention provides a constant current source charging circuit, including: the charging management circuit is electrically connected with the input end of the communication power supply circuit, and the output end of the communication power supply circuit is used for connecting the communication module and at least supplying power to the communication module;
the charging management circuit comprises a switch control module and a constant current limiting module, the power supply is connected with the switch control module, the output end of the switch control module is connected with the input end of the constant current limiting module, and the output end of the constant current limiting module is electrically connected with the input end of the communication power supply circuit so as to realize the constant current charging of the communication power supply circuit by the power supply;
the constant current limiting module comprises a first triode and a three-terminal shunt voltage stabilizer, an emitting electrode of the first triode is connected with a current sampling resistor, and an output end of the current sampling resistor is electrically connected with an input end of the communication power supply circuit.
Optionally, the charging management circuit further includes a microprocessor, the switch control module includes an electronic switch device, a power input end of the electronic switch device is connected to the power supply, and a signal control end of the electronic switch device is connected to the microprocessor.
Optionally, the constant current limiting module includes a first triode and a three-terminal shunt regulator, a collector of the first triode is connected with an output end of the electronic switching device, a bias resistor is connected between the collector and a base of the first triode, an emitter of the first triode is connected with a current sampling resistor, a reference end of the three-terminal shunt regulator is connected to an input end of the current sampling resistor, an anode of the three-terminal shunt regulator is connected to an output end of the current sampling resistor, and a cathode of the three-terminal shunt regulator is connected to a node between the base of the first triode and the bias resistor;
and the output end of the current sampling resistor is electrically connected with the input end of the communication power supply circuit.
Optionally, the electronic switching device is a MOS transistor;
the switch control module further includes: the output end of the power supply terminal is connected with the drain electrode of the MOS tube, and a first decoupling capacitor is arranged between the power supply terminal and the drain electrode;
the input end of the first signal terminal is used for being connected with the microprocessor, the output end of the first signal terminal is connected with the grid electrode of the MOS tube, a first current-limiting resistor is arranged between the first signal terminal and the grid electrode, a first bypass capacitor is further arranged on a node between the output end of the first current-limiting resistor and the grid electrode, and two ends of the first bypass capacitor are further connected with a pull-down resistor in parallel.
Optionally, the charging management circuit further includes an input detection circuit, where the input detection circuit includes a first switch control unit circuit and an input voltage sampling unit circuit;
the first switch control unit circuit is provided with a second signal terminal, the input end of the second signal terminal is used for being connected with the microprocessor, and the output end of the second signal terminal is used for being connected with an external power interface through a second current-limiting resistor, a second triode, a third current-limiting resistor and a third triode in sequence;
and the emitter of the third triode is connected with the external power interface.
Optionally, the input voltage sampling unit circuit includes: the first end of the first divider resistor is connected with the collector of the third triode, the first end of the second divider resistor is connected with the second end of the first divider resistor, the second end of the second divider resistor is grounded, a second bypass capacitor is further arranged on an output line of the second end of the first divider resistor, the second bypass capacitor is connected in parallel with the two ends of the second divider resistor, and the output line of the second end of the first divider resistor is used for being connected with a microprocessor.
Optionally, the charging management circuit further includes an input boost circuit, the input boost circuit includes a boost chip, a filtering unit, an energy storage unit and a voltage dividing unit, the filtering unit and the energy storage unit are respectively connected to the input pin of the boost chip, and the voltage dividing unit is connected to the FB pin of the boost chip.
Optionally, the filtering unit includes a filtering capacitor, the energy storage unit includes an inductor, the voltage dividing unit includes a third voltage dividing resistor and a fourth voltage dividing resistor, the input ends of the filter capacitor and the inductor are used for being connected with an external power interface, the output end of the filter capacitor is connected with a first input pin of the boosting chip, the output end of the inductor is connected with the second input pin of the boosting chip, the enabling pin of the boosting chip is used for being connected with the microprocessor, a first output pin of the boost chip is connected with a first decoupling capacitor of the switch control module, one end of the third voltage dividing resistor and one end of the fourth voltage dividing resistor are respectively connected to the FB pin of the boost chip, the other end of the third voltage dividing resistor is connected to a node between the first output pin and the first decoupling capacitor, and the other end of the fourth voltage dividing resistor is grounded.
Optionally, the communication power supply circuit includes a faraday capacitor and a second decoupling capacitor, the faraday capacitor is used for storing energy, and the second decoupling capacitor is connected in parallel to an input bypass of the faraday capacitor.
Optionally, the power supply detection circuit further comprises a farad capacitor power supply detection circuit, wherein the farad capacitor power supply detection circuit comprises a second switch control unit circuit and a power supply voltage sampling unit circuit;
the charging management circuit further comprises a microprocessor; the second switch control unit circuit is provided with a third signal terminal, the input end of the third signal terminal is used for being connected with the microprocessor, and the output end of the third signal terminal is used for being connected with the output end of the communication power supply circuit through a fourth current-limiting resistor, a fourth triode, a fifth current-limiting resistor and a fifth triode in sequence;
an emitter of the fifth triode is connected with the output end of the communication power supply circuit;
the input voltage sampling unit circuit includes: the first end of the sixth divider resistor is connected with the collector of the fifth triode, the first end of the seventh divider resistor is connected with the second end of the sixth divider resistor, the second end of the seventh divider resistor is grounded, a third bypass capacitor is further arranged on an output line of the second end of the sixth divider resistor, the third bypass capacitor is connected in parallel with the two ends of the seventh divider resistor, and an output line of the second end of the sixth divider resistor is used for being connected with the microprocessor.
Optionally, the electronic switching device includes a sixth transistor and a seventh transistor;
the switch control module further includes: the power supply terminal input end is connected with the power supply, the power supply terminal output end is connected with the emitter of the sixth triode, and a first decoupling capacitor is arranged between the power supply terminal and the emitter;
the input end of the first signal terminal is used for being connected with the microprocessor, the output end of the first signal terminal is connected with the base electrode of the seventh triode, a sixth current limiting resistor is arranged between the first signal terminal and the base electrode, the emitting electrode of the seventh triode is connected with the base electrode of the sixth triode through the seventh current limiting resistor, and the collecting electrode of the sixth triode is connected with the input end of the constant current limiting module.
Optionally, the first decoupling capacitor includes a first capacitor and a second capacitor that are arranged in parallel at the output end of the power supply terminal, and the other ends of the first capacitor and the second capacitor are grounded respectively.
In a second aspect, the present invention provides a gas meter with a constant current source charging circuit, including the base table and set up the controller on the base table, be equipped with the main control board in the controller be equipped with communication module on the main control board and reach the constant current source charging circuit, the constant current source charging circuit is arbitrary for the first aspect the constant current source charging circuit, the communication supply circuit's of constant current source charging circuit output with communication module's power supply terminal connects.
The embodiment of the utility model provides a constant current source charging circuit and have its intelligent gas table, include: the charging management circuit is electrically connected with the input end of the communication power supply circuit, and the output end of the communication power supply circuit is used for connecting a communication module and at least supplying power to the communication module; the charging management circuit comprises a switch control module and a constant current limiting module, the power supply is connected with the switch control module, the output end of the switch control module is connected with the input end of the constant current limiting module, and the output end of the constant current limiting module is electrically connected with the input end of the communication power supply circuit so as to clamp the voltage of the communication power supply circuit. The charging management circuit is arranged, the on-off control module of the charging management circuit is used for carrying out intelligent management control on the on-off of an input power supply, and the like, the constant current limiting module is adopted to replace the current limiting scheme of the current limiting resistor, the voltage of the communication power supply circuit is clamped, so that the constant current limiting charging of the communication power supply circuit is realized, further, the constant current limiting charging is realized for the charging current of the communication power supply circuit, when the communication power supply circuit is charged, the current for charging the communication power supply circuit keeps constant current, and the working voltage of a pull-down microprocessor system and other peripheral function circuits basically cannot appear. Therefore, the constant-current-limiting charging of the communication power supply circuit is realized, the working voltage of other electric elements or functional circuits is basically not influenced, and the normal work of the system and the functional circuits is ensured to a certain extent. Therefore, the circuit can be well suitable for products which have large limitation requirements on external input power and simultaneously have remote communication and multifunctional circuits.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a circuit block diagram of an embodiment of the constant current source charging circuit of the present invention;
fig. 2 is a schematic circuit diagram of another embodiment of the constant current source charging circuit of the present invention;
fig. 3 is a schematic circuit diagram of another embodiment of the constant current source charging circuit of the present invention;
fig. 4 is a schematic circuit diagram of another embodiment of the constant current source charging circuit of the present invention.
Detailed Description
The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
It should be apparent that numerous technical details are set forth in the following detailed description to provide a more thorough description of the present invention, and it will be apparent to those skilled in the art that the present invention may be practiced without some of these details. In addition, some methods, means, components and applications thereof known to those skilled in the art are not described in detail in order to highlight the gist of the present invention, but the implementation of the present invention is not affected thereby. The embodiments described herein are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.
The embodiment of the utility model provides a constant current source charging circuit and have its intelligent gas table through setting up specific charge management circuit, power needs when can satisfying communication module communication also can not influence the normal operating voltage requirement of MCU microprocessor system and other functional circuits when normal communication. Meanwhile, the charging start time, the charging duration and the like of the farad capacitor can be controlled in real time, the intelligent power supply management of the communication module is realized, the static power consumption of the communication module can be reduced, and the static power consumption of a product with the communication module is further reduced. This scheme is applicable to and has great restriction to external input power, has remote communication and multifunctional circuit's product again simultaneously, for example intelligent gas table.
Example one
Referring to fig. 1, the embodiment of the present invention provides a constant current source charging circuit 1, including: the charging management circuit comprises a charging management circuit and a communication power supply circuit 2, wherein the input end of the charging management circuit is used for being connected with a power supply source, the output end of the charging management circuit is electrically connected with the input end of the communication power supply circuit 2, and the output end of the communication power supply circuit 2 is used for being connected with a communication module and at least used for supplying power for the communication module.
The charging management circuit comprises a switch control module 3 and a constant current limiting module 4, the power supply is connected with the switch control module, the output end of the switch control module is connected with the input end of the constant current limiting module, and the output end of the constant current limiting module is electrically connected with the input end of the communication power supply circuit to clamp the voltage of the communication power supply circuit, so that constant current charging is realized.
Specifically, the charging management circuit further comprises a microprocessor, the switch control module 3 comprises an electronic switch device, a power input end of the electronic switch device is connected with the power supply, a signal control end of the electronic switch device is connected with the microprocessor, and an output end of the electronic switch device is connected with an input end of the constant current limiting module 4.
The microprocessor pin can directly control the on and off of an electronic switch device of the switch control module 3, so that the on and off of the input power supply are controlled, the on time, the on duration, the off time, the off duration and the like of the input power supply are controlled, and the intelligent control of the input power supply is realized.
Referring to fig. 2 and 3, in some embodiments, the electronic switching device is a MOS transistor, which is called a metal-oxide-semiconductor (semiconductor) field effect transistor. The MOS tube can be an NMOS field effect tube control circuit and can also use a PMOS field effect tube, and what is different is that if the NMOS tube used by the electronic switch device is changed into the PMOS tube, the conduction resistance of the general P-channel MOS tube is larger than that of the N-channel MOS tube under the same current and rated voltage, the switching speed is slower than that of the N-channel MOSFET tube, so the N-channel MOSFET tube is commonly used in the switch circuit, and the P-channel MOSFET tube is generally used in a normally open bus circuit.
The switch control module 3 further includes: power supply terminal VCCAnd a first signal terminal, wherein the power supply terminal output terminal is connected to the drain of the MOS transistor Q2, and the power supply terminal V isCCA first decoupling capacitor C1 and a first decoupling capacitor C2 are arranged between the input power supply and the drain electrode and used for storing energy for the input power supply and filtering a bypass high-frequency noise signal;
the input end of the first signal terminal is used for being connected with the microprocessor, the EDLC _ PWR-CHARGE-CTL is arranged on the input end of the first signal terminal, the output end of the first signal terminal is connected with the grid electrode of the MOS tube Q2, and the microprocessor finishes the control of the on-off of the MO S tube Q2 by outputting high and low levels to the input end of the first signal terminal and transmitting the high and low levels in the switch control module; a first current limiting resistor R6 is arranged between the first signal terminal and the grid, a first bypass capacitor C8 is further arranged on a node between the output end of the first current limiting resistor R6 and the grid, and the first bypass capacitor C8 is a bypass capacitor of an EDLC _ PWR-CHARGE-C TL level signal input from the first signal terminal and plays a role in resisting interference and reducing noise signals; the two ends of the first bypass capacitor C8 are also connected in parallel with a pull-down resistor R7, and the first current limiting resistor R6 and the pull-down resistor R7 complete the fixing of the gate level of the MOS transistor Q2 together.
The communication power supply circuit at least comprises an energy storage element, such as a farad capacitor, and is used for supplying power to functional circuit modules such as a communication module. In some embodiments, the communication supply circuit 2 comprises a farad capacitor C4. The farad capacitor C4 is used as an energy storage element to provide a power supply for the communication module, and farad capacitors with small leakage current and withstand voltage value of more than 1.5 times of working voltage are preferred; wherein farad leakage current is more than or equal to 0 and less than or equal to 20 uA.
The communication module comprises any one of a GPRS module, an NB-IOT module, a Lora-WAN and Bluetooth.
When the communication module needs to communicate, a control signal can be sent to an electronic switch device of the switch control module 3 through a control pin of the microprocessor MCU, a switch of the switch control module 3 is turned on, current limitation is carried out on an input power supply through the constant current limiting module 4 so as to meet the electrical and explosion-proof safety standard, and the input power supply is output and supplied to the farad capacitor for charging, so that the farad capacitor is used as a power supply for remote communication to supply power to the communication module.
The input power supply can be supplied by external alternating current or external lithium batteries. The charging time of the farad capacitor is related to the capacitance value of the farad capacitor and the constant current limiting value, and can be set in advance through a microprocessing MCU after theoretical calculation or actual test, so that intelligent control management is realized.
Because farad capacitor self has the leakage current, even if not communicating also can consume the energy, consequently, when thing networking communication module need not communicate, can turn off switch control module 3's switch through microprocessor MCU's control pin, stop providing the power to farad capacitor and charge for it. Therefore, the loss of power or energy of the input power supply can be reduced by controlling the switch-off of the switch control module 3, so that the utilization rate of the external input power supply of the circuit or the service life of a battery is improved.
It can be understood that, when the remote communication is performed, due to the rapid energy consumption of the faraday capacitor, if the charging current of the faraday capacitor is not limited, the power supply is not sufficient, and the operating voltage of the microprocessor system and other peripheral functional circuits is directly pulled down, so that the operating voltage of the microprocessor system or other peripheral functional circuits is lower than the lowest operating voltage, which affects the normal operation of the product. If the input power source is a lithium battery, the external power supply condition can exist when the remote communication is carried out, so that the rated voltage of the battery is pulled down to be the lowest voltage or the cut-off voltage, and the normal use of the battery is influenced.
In order to prevent the above problems, in this embodiment, the constant current limiting module 4 is arranged to perform constant current limiting on the load current, and keep the current for charging the next stage farad capacitor constant, so that the constant current limiting charging of the farad capacitor is realized while the working voltage of other electric elements or functional circuits is not affected, and the normal operation of the system and the functional circuits is ensured to a certain extent.
Referring to fig. 2, the constant current limiting module 4 includes a first triode Q1 and a three-terminal shunt regulator U1, a collector of the first triode Q1 is connected to an output terminal of the electronic switching device, a bias resistor R4 is connected between the collector and a base of the first triode Q1, the resistance of the bias resistor R4 is such that the triode can reach a saturation conducting state, an emitter of the first triode Q1 is connected to a current sampling resistor R2, a reference terminal of the three-terminal shunt regulator U1 is connected to an input terminal of the current sampling resistor R2, an anode of the three-terminal shunt regulator U1 is connected to an output terminal of the current sampling resistor R2, and a cathode of the three-terminal shunt regulator U1 is connected to a node between the base of the first triode Q1 and the bias resistor R4; the output end of the current sampling resistor R2 is electrically connected with the input end of the communication power supply circuit 2.
The three-terminal shunt regulator U1 is a TL431 three-terminal adjustable shunt regulator, and is a core component of the constant current limiting module 4, the first triode Q1 is preferably an NPN type, and serves as a constant current regulating tube, and serves as a bias resistor R4 of the first triode Q1, and when the first triode Q1 is selected, the resistance value of the first triode Q1 is required to be in a saturated conduction state. The resistance value of the current sampling resistor R2 determines the magnitude of an output current (Iout), when the load resistance is reduced, the current is increased to Iout from 0mA, the Vref power supply of the TL431 is +2.5V, the voltage at two ends of the current sampling resistor R2 is forced to reach the reference voltage Vref (2.5V), the three-terminal shunt regulator U1 is started and conducted, the base current of the first triode Q1 is reduced, the conduction degree of the first triode Q1 is reduced, the current is stabilized at Iout, and therefore constant current output is achieved.
In some embodiments, the three-terminal shunt regulator U1 may also be replaced with a zener diode. The TL431 three-terminal adjustable shunt voltage stabilizer and the current sampling resistor R2 are high-precision and low-temperature-drift materials, and can enable constant current to achieve high-precision output.
In addition, in the conventional low power consumption product, a power supply part of the communication module is also supplied with power by a combination of a lithium battery and an SPC battery capacitor. Because SPC battery capacitor cost is slightly higher, simultaneously because output current peak value is slightly higher, restriction requirement when explosion-proof product design also can lead to the not enough condition of electric energy utilization. The constant current source charging circuit scheme provided by the embodiment replaces the existing SPC battery capacitor, the overall design cost of the product can be effectively reduced, and meanwhile, the circuit topology is simple and reliable, and the application and popularization are convenient.
Referring to fig. 3, as an alternative embodiment, the charging management circuit further includes an input detection circuit 5, configured to detect an input power voltage, where network labels of the input detection circuit 5 are MCU-PWR _ NB-AD-CTL and MCU-PWR _ NB-AD, and the input detection circuit is directly connected to an I/O port of the microprocessor MCU, and is respectively used for control of a corresponding functional circuit and acquisition of a voltage signal, and finally, the input detection circuit and the other functional circuits implement intelligent charging control and management of the remote communication power supply.
Specifically, the input detection circuit 5 includes a first switch control unit circuit and an input voltage sampling unit circuit; the first switch control unit circuit is provided with a second signal terminal, the network label of the second signal terminal is MCU-PWR _ NB-AD-CTL, the input end of the second signal terminal is used for being connected with the microprocessor, and the output end of the second signal terminal is used for being connected with an external power interface through a second current limiting resistor R15, a second triode Q6, a third current limiting resistor R13 and a third triode Q4 in sequence; wherein an emitter of the third transistor Q4 is connected to the external power interface.
The input detection circuit 5 is specifically an AD detection circuit of an input power supply, and in the input detection circuit 5, an input end MCU-PWR _ NB-AD-CTL of a second signal terminal outputs a high-level signal at regular time by a microprocessor, so that two triodes, namely a second triode Q6 and a third triode Q4, are in saturation conduction.
The input voltage sampling unit circuit is used for monitoring the change of the input power supply voltage value in real time and playing a role in early warning for the input power supply voltage required by the work of the communication module and the input power supply voltage required by the work of the master control system. Meanwhile, when the consumption of the electric quantity of an external lithium battery, an alkaline battery or other external input power supply is lower than a set minimum threshold value, the replacement reminding function is played. Therefore, the intelligent management of the power supply voltage on the farad capacitor is facilitated, the intelligent charging and remote communication control are completed by combining with other functional circuits in the embodiment, and the intelligent operations of data remote transmission, data interaction, instruction issuing and the like are realized.
The input voltage sampling unit circuit includes: a first divider resistor R9 and a second divider resistor R11, a first end of the first divider resistor R9 is connected to a collector of the third transistor Q4, a first end of the second divider resistor R11 is connected to a second end of the first divider resistor R9, a second end of the second divider resistor R11 is grounded, a second bypass capacitor C10 is further disposed on an output line of a second end of the first divider resistor R9, the second bypass capacitor C10 is connected in parallel to two ends of the second divider resistor R11, and an output line of the second end of the first divider resistor R9 is used for being connected to a microprocessor.
The output line network label of the second end of the first voltage-dividing resistor R9 is the MCU-PWR _ NB-AD described above. The first voltage dividing resistor R9 and the second voltage dividing resistor R11 are used for collecting voltage signals of an input power supply, inputting the voltage signals into an AD pin of the microprocessor, and converting analog input into digital values through an A/D converter in the microprocessor; the second bypass capacitor c10 is a bypass capacitor of the input voltage sampling unit circuit and is used for bypassing the high-frequency interference signal input to the a/D pin of the microprocessor.
With continued reference to fig. 3, in some alternative embodiments, the charge management circuit further includes an input boost circuit 6, the input boost circuit 6 including a boost chip U2, filter capacitors C6 and C7, an inductor; l1, a third voltage dividing resistor R3 and a fourth voltage dividing resistor R5, wherein the filter capacitors C6 and C7 and the input end of the inductor are used for being connected with an external power interface, the output ends of the filter capacitors C6 and C7 are connected with the first input pin VIN of the boost chip U2, the output end of the inductor L1 is connected with the second input pin SW of the boost chip U2, the enable pin EN of the boost chip U2 is used for connecting with a microprocessor, the first output pin VOUT of the boost chip U2 is connected with the first decoupling capacitor C1 of the switch control module 3, one end of the third voltage dividing resistor R3 and one end of the fourth voltage dividing resistor R5 are respectively connected to the FB pin of the boost chip U2, the other end of the third voltage dividing resistor R3 is connected to a node between the first output pin and the first decoupling capacitor, and the other end of the fourth voltage dividing resistor R5 is grounded.
The input boost circuit 6 is specifically an input power DC-DC boost circuit, and a boost chip U2 with low static power consumption, low voltage range and high output efficiency, such as a product related to Texas Instruments (Texas Instruments) and other manufacturers, may be used to maintain the power consumption of the input boost circuit 6 at an extremely low level, and reduce the consumption of the electric energy of the external input power. Meanwhile, a pin 4 in the boost chip U2 is a logic enable input pin of the chip, the pin is used for being connected to a microprocessor, the microprocessor is used for controlling the operation and the stop of the boost chip U2, the power consumption of the input boost circuit 6 can be effectively reduced, and therefore the service life of an input power supply is prolonged.
In the constant current source charging circuit of the present embodiment, the purpose of using this input power source DC-DC boost circuit is to maintain the length of time of remote communication when remote communication is performed, in order to increase the charging voltage of the back-end super capacitor. The filter capacitors C6 and C7 in the circuit are used as input capacitors of the DC-DC booster circuit and are used for inhibiting peak signals of input voltage and providing stable input power for a chip; the inductor L1 is an input inductor and plays a key role in the stability of a DC-DC power supply system loop of the input booster circuit 6; the third voltage dividing resistor R3 and the fourth voltage dividing resistor R5 are external resistor voltage dividers of the boost chip U2, and the actually required voltage value can be obtained by changing the resistance values.
Referring to fig. 2 to 4, the communication power supply circuit 2 includes a farad capacitor C4 and a second decoupling capacitor C3, the farad capacitor C4 is used for storing energy and supplying power to the communication module, and the input side of the farad capacitor is connected in parallel with the second decoupling capacitor C3, which and the side bypass capacitor can be called as a filter capacitor, and the filter capacitor and the side bypass capacitor have different names and different positions in the circuit, and play a role in resisting interference and reducing noise signals.
Referring to fig. 3, in other embodiments, the communication power supply circuit 2 further includes a farad capacitor power supply detection circuit 7 for monitoring a change in voltage value of a farad capacitor power supply for remote communication in real time; the farad capacitor power supply detection circuit 7 comprises a second switch control unit circuit and a power supply voltage sampling unit circuit;
the second switch control unit circuit is provided with a third signal terminal, the input end of the third signal terminal is used for being connected with the microprocessor MCU, and the output end of the third signal terminal is connected with the output end of the communication power supply circuit 2 through a fourth current limiting resistor R14, a fourth triode Q5, a fifth current limiting resistor R12 and a fifth triode Q3 in sequence:
the emitter of the fifth triode Q3 is connected with the output end of the communication power supply circuit 2;
the input voltage sampling unit circuit includes: sixth divider resistance R8 and seventh divider resistance R10, the first end of sixth divider resistance R8 with the collecting electrode of fifth triode Q3 is connected, seventh divider resistance R10 first end connect in sixth divider resistance R8's second end, seventh divider resistance R10 second end ground connection, still be equipped with third bypass electric capacity C9 on the output line of sixth divider resistance R8's second end, third bypass electric capacity C9 connect in parallel in seventh divider resistance R10 both ends, the output line of sixth divider resistance R8 second end is used for being connected with microprocessor NCU.
In an AD detection circuit of a remote communication power supply, namely a farad capacitor power supply detection circuit, a high-level signal MCU-EDLC _ PWR-AD-CTL which is output by an MCU microprocessor at fixed time is input to a third signal terminal, so that two triodes of a fourth triode Q5 and a fifth triode Q3 are conducted in a saturated mode; the sixth voltage-dividing resistor and the seventh voltage-dividing resistor R10 are used for collecting voltage signals of the Farad capacitor power supply and outputting the voltage signals to an AD pin of the microprocessor, and analog input is converted into digital values through an A/D converter in the microprocessor; and the third bypass capacitor C9 is used for filtering high-frequency interference signals input into the A/D pin of the MCU microprocessor.
In this embodiment, through this farad capacitor power supply detection circuitry, the change of remote communication power supply voltage value can real-time supervision, plays the effect of early warning for communication module's mains voltage, is more convenient for implement intelligent management to the mains voltage on the farad capacitor to combine other functional circuit to accomplish intelligent charging and telecommunication, with intelligent operations such as realize data teletransmission, data interaction, instruction issue.
Besides the MOS transistor Q2, the electronic switching device may also use a triode to turn on and off the circuit. In an alternative embodiment, as shown with reference to fig. 4, the electronic switching device includes a sixth transistor Q2 and a seventh transistor Q3;
the switch control module 3 further includes: the power supply terminal VCC and the first signal terminal, the output terminal of the power supply terminal is connected with the emitter of the sixth triode Q2, and a first decoupling capacitor C1 and a first decoupling capacitor C2 are arranged between the power supply terminal and the emitter;
the input end of the first signal terminal is used for being connected with the microprocessor, the output end of the first signal terminal is connected with the base electrode of the seventh triode Q3, a sixth current-limiting resistor R6 is arranged between the first signal terminal and the base electrode, the emitter of the seventh triode Q3 is connected with the base electrode of the sixth triode Q2 through a seventh current-limiting resistor R7, and the collector of the sixth triode Q2 is connected with the input end of the constant current-limiting module 4.
In the alternative of this embodiment, a transistor is used as the switching device, and the on and off control of the switch can also be realized, compared with a MOS transistor Q2 as the switching device, the transistor has the characteristic of low price, and the limitation is that the transistor is generally suitable for the occasion of low-current switching control because the saturated conduction current of the transistor is generally lower than the conduction current of the MOSFET, and certainly, the transistor can meet the switching control of the product applied in the scheme of the present application.
The embodiment of the utility model provides a constant current source charging circuit, including charging management circuit and communication supply circuit, through setting up charging management circuit, utilize its on-off control module 3 to carry out the intelligent management control of break-make etc. to the input power to adopt constant current limiting module 4 to replace current limiting resistance current-limiting scheme, to the voltage clamp of communication supply circuit, in order to realize the constant current limiting charging to communication supply circuit; because the charging current of the communication power supply circuit is charged in a constant current limiting manner, the charging current of the communication power supply circuit keeps constant current when the communication power supply circuit is charged, and the working voltage of a pull-down microprocessor system and other peripheral functional circuits is basically avoided. Therefore, the constant-current-limiting charging of the farad capacitor of the communication power supply circuit is realized, the working voltage of other electric elements or functional circuits is basically not influenced, and the normal work of the system and the functional circuits is ensured to a certain extent. Therefore, the circuit can be well suitable for products which have large limitation requirements on external input power and simultaneously have remote communication and multifunctional circuits.
Example two
Based on embodiment a constant current source charging circuit's that provides basis, the embodiment of the utility model provides a still provides a gas table with constant current source charging circuit, include the base table and set up the controller on the base table, be equipped with the main control board in the controller be equipped with communication module on the main control board and reach constant current source charging circuit, constant current source charging circuit is one of the embodiment constant current source charging circuit, constant current source charging circuit's communication supply circuit 2's output with communication module's power supply terminal is connected, is used for doing communication module supplies power.
The gas meter with the constant current source charging circuit provided by this embodiment can realize remote intelligent management on the on and off of the input power supply of the gas meter due to the constant current source charging circuit provided by the first embodiment, and can realize constant current limited charging of the communication module during remote communication, and basically does not affect the working voltage of other electric elements or functional circuits, thereby ensuring the normal operation of the gas meter system and the associated functional circuits to a certain extent.
It should be noted that the terms "upper", "lower", and the like, herein indicate orientations and positional relationships, and are only used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; may be directly connected or indirectly connected through an intermediate. Relational terms such as first and third, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, 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 identical elements in a process, method, article, or apparatus that comprises the element. As will be appreciated by one of ordinary skill in the art, the situation may be specified.
The above description is only for the specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (13)
1. A constant current source charging circuit, comprising: the charging management circuit is electrically connected with the input end of the communication power supply circuit, and the output end of the communication power supply circuit is used for connecting the communication module and at least supplying power to the communication module;
the charging management circuit comprises a switch control module and a constant current limiting module, the power supply is connected with the switch control module, the output end of the switch control module is connected with the input end of the constant current limiting module, and the output end of the constant current limiting module is electrically connected with the input end of the communication power supply circuit so as to realize the constant current charging of the communication power supply circuit by the power supply;
the constant current limiting module comprises a first triode and a three-terminal shunt voltage stabilizer, an emitting electrode of the first triode is connected with a current sampling resistor, and an output end of the current sampling resistor is electrically connected with an input end of the communication power supply circuit.
2. The constant current source charging circuit of claim 1, wherein the charging management circuit further comprises a microprocessor, the switch control module comprises an electronic switching device, a power input terminal of the electronic switching device is connected to the power source, and a signal control terminal of the electronic switching device is connected to the microprocessor.
3. The charging circuit of claim 2, wherein the collector of the first transistor is connected to the output of the electronic switching device, a bias resistor is connected between the collector and the base of the first transistor, the reference terminal of the three-terminal shunt regulator is connected to the input of the current sampling resistor, the anode of the three-terminal shunt regulator is connected to the output of the current sampling resistor, and the cathode of the three-terminal shunt regulator is connected to the node between the base of the first transistor and the bias resistor.
4. The constant current source charging circuit according to claim 2, wherein the electronic switching device is a MOS transistor;
the switch control module further includes: the output end of the power supply terminal is connected with the drain electrode of the MOS tube, and a first decoupling capacitor is arranged between the power supply terminal and the drain electrode;
the input end of the first signal terminal is used for being connected with the microprocessor, the output end of the first signal terminal is connected with the grid electrode of the MOS tube, a first current-limiting resistor is arranged between the first signal terminal and the grid electrode, a first bypass capacitor is further arranged on a node between the output end of the first current-limiting resistor and the grid electrode, and two ends of the first bypass capacitor are further connected with a pull-down resistor in parallel.
5. The constant current source charging circuit according to claim 4, wherein the charging management circuit further comprises an input detection circuit, the input detection circuit comprising a first switch control unit circuit and an input voltage sampling unit circuit;
the first switch control unit circuit is provided with a second signal terminal, the input end of the second signal terminal is used for being connected with the microprocessor, and the output end of the second signal terminal is used for being connected with an external power interface through a second current-limiting resistor, a second triode, a third current-limiting resistor and a third triode in sequence;
and the emitter of the third triode is connected with the external power interface.
6. The constant current source charging circuit according to claim 5, wherein the input voltage sampling unit circuit comprises: the first end of the first divider resistor is connected with the collector of the third triode, the first end of the second divider resistor is connected with the second end of the first divider resistor, the second end of the second divider resistor is grounded, a second bypass capacitor is further arranged on an output line of the second end of the first divider resistor, the second bypass capacitor is connected in parallel with the two ends of the second divider resistor, and the output line of the second end of the first divider resistor is used for being connected with a microprocessor.
7. The constant current source charging circuit of claim 2, wherein the charging management circuit further comprises an input boost circuit, the input boost circuit comprises a boost chip, a filtering unit, an energy storage unit and a voltage dividing unit, the filtering unit and the energy storage unit are respectively connected to the input pin of the boost chip, and the voltage dividing unit is connected to the FB pin of the boost chip.
8. The charging circuit of claim 7, wherein the filtering unit comprises a filtering capacitor, the energy storage unit comprises an inductor, the voltage dividing unit comprises a third voltage dividing resistor and a fourth voltage dividing resistor, the filtering capacitor is connected to an input terminal of the inductor for connecting to an external power interface, an output terminal of the filtering capacitor is connected to a first input pin of the voltage boosting chip, an output terminal of the inductor is connected to a second input pin of the voltage boosting chip, an enable pin of the voltage boosting chip is connected to the microprocessor, a first output pin of the voltage boosting chip is connected to a first decoupling capacitor of the switch control module, one end of each of the third voltage dividing resistor and the fourth voltage dividing resistor is connected to a FB pin of the voltage boosting chip, and the other end of the third voltage dividing resistor is connected to a node between the first output pin and the first decoupling capacitor, the other end of the fourth voltage-dividing resistor is grounded.
9. The charging circuit for a constant current source according to claim 1, wherein the communication power supply circuit comprises a farad capacitor and a second decoupling capacitor, the farad capacitor is used for storing energy, and the second decoupling capacitor is connected in parallel to an input bypass of the farad capacitor.
10. The constant current source charging circuit according to claim 9, further comprising a farad capacitance power supply detection circuit including a second switch control unit circuit and a power supply voltage sampling unit circuit;
the charging management circuit further comprises a microprocessor;
the second switch control unit circuit is provided with a third signal terminal, the input end of the third signal terminal is used for being connected with the microprocessor, and the output end of the third signal terminal is used for being connected with the output end of the communication power supply circuit through a fourth current-limiting resistor, a fourth triode, a fifth current-limiting resistor and a fifth triode in sequence;
an emitter of the fifth triode is connected with the output end of the communication power supply circuit;
the input voltage sampling unit circuit includes: the first end of the sixth divider resistor is connected with the collector of the fifth triode, the first end of the seventh divider resistor is connected with the second end of the sixth divider resistor, the second end of the seventh divider resistor is grounded, a third bypass capacitor is further arranged on an output line of the second end of the sixth divider resistor, the third bypass capacitor is connected in parallel with the two ends of the seventh divider resistor, and an output line of the second end of the sixth divider resistor is used for being connected with the microprocessor.
11. The constant current source charging circuit according to claim 2, wherein the electronic switching device further comprises a sixth transistor and a seventh transistor;
the switch control module further includes: the power supply terminal input end is connected with the power supply, the power supply terminal output end is connected with the emitter of the sixth triode, and a first decoupling capacitor is arranged between the power supply terminal and the emitter;
the input end of the first signal terminal is used for being connected with the microprocessor, the output end of the first signal terminal is connected with the base electrode of the seventh triode, a sixth current limiting resistor is arranged between the first signal terminal and the base electrode, the emitting electrode of the seventh triode is connected with the base electrode of the sixth triode through the seventh current limiting resistor, and the collecting electrode of the sixth triode is connected with the input end of the constant current limiting module.
12. The constant current source charging circuit according to claim 11, wherein the first decoupling capacitor comprises a first capacitor and a second capacitor connected in parallel to the output terminal of the power supply terminal, and the other ends of the first capacitor and the second capacitor are grounded, respectively.
13. A gas meter with a constant current source charging circuit is characterized by comprising a base meter and a controller arranged on the base meter, wherein a main control board is arranged in the controller, a communication module and a constant current source charging circuit are arranged on the main control board, the constant current source charging circuit is the constant current source charging circuit according to any one of claims 1 to 12, and the output end of a communication power supply circuit of the constant current source charging circuit is connected with a power supply terminal of the communication module.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021730356.8U CN212935542U (en) | 2020-08-18 | 2020-08-18 | Constant current source charging circuit and gas meter with same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202021730356.8U CN212935542U (en) | 2020-08-18 | 2020-08-18 | Constant current source charging circuit and gas meter with same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN212935542U true CN212935542U (en) | 2021-04-09 |
Family
ID=75299138
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202021730356.8U Active CN212935542U (en) | 2020-08-18 | 2020-08-18 | Constant current source charging circuit and gas meter with same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN212935542U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115083358A (en) * | 2022-07-05 | 2022-09-20 | 珠海格力电器股份有限公司 | Display panel backlight control circuit and control method |
| WO2023000367A1 (en) * | 2021-07-20 | 2023-01-26 | Tcl华星光电技术有限公司 | Current limiting circuit |
-
2020
- 2020-08-18 CN CN202021730356.8U patent/CN212935542U/en active Active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2023000367A1 (en) * | 2021-07-20 | 2023-01-26 | Tcl华星光电技术有限公司 | Current limiting circuit |
| CN115083358A (en) * | 2022-07-05 | 2022-09-20 | 珠海格力电器股份有限公司 | Display panel backlight control circuit and control method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102027662B (en) | Current-mode control switching regulator and operations control method thereof | |
| CN100525040C (en) | Sample-taking feedback circuit of switch electric power output electric voltage | |
| CN101924471B (en) | Method for constantly outputting current and device thereof | |
| CN208971380U (en) | Soft starting circuit, control chip, buck converter and boost converter | |
| CN108695956A (en) | Wireless charging and telecommunication circuit and radio-based electronic devices | |
| CN106208369A (en) | A kind of on-line monitoring device of intelligent type low-voltage circuit breaker | |
| CN101471603B (en) | DC-DC decompression converter and ripple improving circuit | |
| CN212935542U (en) | Constant current source charging circuit and gas meter with same | |
| CN205319941U (en) | Double - circuit voltage conversion control chip , double - circuit voltage conversion ware and electronic electric energy meter | |
| CN106787665A (en) | A kind of instrument valve power supply control system | |
| CN107294373B (en) | One kind trembling frequency control circuit and control method | |
| CN109639118B (en) | Self-powered circuit of switching power supply, control chip, switching power supply and electric device | |
| CN203135728U (en) | Voltage switching circuit and switch circuit | |
| CN202978700U (en) | Voltage conversion circuit | |
| CN209526556U (en) | Power supply switch circuit | |
| CN207069898U (en) | One kind trembles frequency control circuit | |
| Kularatna | Modern component families and circuit block design | |
| CN101364771B (en) | Single chip controlled power supply apparatus | |
| CN112787518A (en) | Current mode staggered control converter and control chip | |
| CN113525172A (en) | Lithium battery integrated protection plate, power battery pack and electric vehicle | |
| CN101409503B (en) | Feedback comparing device and DC-to-DC voltage converter | |
| CN201075826Y (en) | Power adapter controlled by single chip | |
| CN219498993U (en) | Charging circuit and device of battery | |
| CN104283245A (en) | High-conversion-efficiency mobile power source circuit | |
| CN221328662U (en) | Mobile power supply control circuit and mobile power supply |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20231107 Address after: 325600 291 weft seventeen Road, Yueqing Economic Development Zone, Wenzhou, Zhejiang Patentee after: Goldcard Smart Group Co.,Ltd. Patentee after: Tancy Instrument Group Co.,Ltd. Address before: 325600 291 weft seventeen Road, Yueqing Economic Development Zone, Wenzhou, Zhejiang Patentee before: Goldcard Smart Group Co.,Ltd. |
|
| TR01 | Transfer of patent right |