Today, I will introduce a national invention authorized patent-a fast power-off circuit for gas meters. The patent was applied for by Golden Card Smart Group Co., Ltd. and was authorized and announced on September 4, 2018.
Content descriptionThe utility model belongs to the field of gas meters, and particularly relates to a quick power-off circuit for gas meters.
Background of the inventionThe current smart gas meter uses NB-IoT communication technology for intelligent data transmission, fault information upload and valve remote control. Due to the low power consumption, wide coverage, large access volume, and low cost of use of NB-IoT communication technology, NB-IoT communication technology has begun to gradually replace GPRS communication technology in the Internet of Things field. As the NB-IoT communication technology becomes more and more widely used, the failures of unsuccessful device access to the network, abnormal response to module commands or non-response are gradually increasing, making the communication process based on NB-IoT devices continue to search the network or communication stagnation, and finally Cause the communication to fail. In response to the above-mentioned failures, the R&D personnel added the power-off restart module function to the device in the design, and tried multiple communication data interaction operations when a communication failure occurred, thereby improving the communication success rate.
The DC-DC step-down circuit that provides power for the power-off restart module in the smart gas meter is the DC-DC step-down circuit, which controls the power on and off by controlling the enable pin in the DC-DC step-down circuit, so that the front end of the NB-IoT communication module The filter capacitor is discharged below the reset voltage threshold of the NB-IoT communication module to realize the restart of the communication module. However, the large value of the power feedback resistance of the DC-DC step-down circuit in low-power products results in too long discharge time of the filter capacitor, which cannot guarantee the reliable restart of the NB-IoT communication module, which affects the normal operation of the smart gas meter.
Summary of the inventionIn order to solve the shortcomings and deficiencies in the prior art, the present utility model provides a quick disconnection for gas meters based on the conduction state of the triode to make the capacitor in the voltage stabilizing circuit quickly discharge, and thereby quickly reset the NB-IoT communication circuit. Electric circuit.
In order to achieve the above technical purpose, the present invention provides a fast power-off circuit for gas meters, including a DCDC voltage stabilizing circuit, and an NB-IoT communication circuit connected to the output of the DC-DC voltage stabilizing circuit. A discharge circuit is provided between the voltage stabilizing circuit and the NB-IoT communication circuit. The discharge circuit includes: a transistor Q3, the base of the transistor Q3 is connected to the control pin CTR1, the emitter of the transistor Q3 is grounded, and the collector of the transistor Q3 It is connected with the output terminal of the DC-DC voltage stabilizing circuit; the collector of the transistor Q3 is also connected with a resistor R3, and a resistor R6 is arranged between the base of the transistor Q3 and the control pin CTR1.
Optionally, the DC-DC voltage stabilizing circuit includes: a voltage stabilizing chip U1 and a switching tube Q1 connected to the input end of the stabilizing chip, the drain of the switching tube Q1 is connected to the input end of the stabilizing chip, and the source of the switching tube Q1 The pole is connected with the power supply terminal; the gate of the switching tube Q1 is connected with a transistor Q2, the collector of the transistor Q2 is connected via a resistor R5 to the pin IC_CTR1 that is used to output the data communication state corresponding to the high and low levels, the emitter of the transistor Q2 and the voltage regulator Chip connection.
Optionally, the DC-DC voltage stabilizing circuit includes: an inductor L1 connected to the output end of the voltage stabilizing chip; the end of the inductor L1 away from the voltage stabilizing chip is connected to a filter capacitor C1 and a resistor R4 and resistor R8 connected in series; the voltage stabilizing chip The resistor R7 is also connected to the resistor R7, and the other end of the resistor R7 and the resistor R8 is grounded away from the resistor R4.
Optionally, the DC-DC voltage stabilizing circuit includes a resistor R1 and a capacitor C3 connected in parallel to the input end of the voltage stabilizing chip, and a capacitor C2 is also connected in parallel to both ends of the resistor R1 and the capacitor C3.
The beneficial effects of the technical solution provided by the utility model are as follows: 1. By adding a discharge circuit to the existing gas meter circuit, the transistor Q3 is turned on when the communication circuit fails, so that the rapid discharge operation is realized, thereby enabling the communication The circuit restarts quickly, reducing the abnormal state of the gas meter due to communication failure, preventing the increase of data transmission time due to communication abnormality, and improving the communication success rate of the gas meter.
2. According to the different working status of the communication circuit, make the corresponding level signal output by the pin IC_CTR1, make the DC-DC power supply enable pin control the power off, turn on the discharge loop control switch, and quickly discharge the filter capacitor through the discharge loop. The communication module The reset is successful; and after a certain period of delay, the enable pin controls the power to be turned on, and the communication circuit is powered on to restart.
Mini PC
Are you tired on big and messy wires on traditional computer tower? If yes, mini pc bring clean and space saving working environment back to you. Whatever daily tasks, like browsing web pages, documents checking or making, online teaching or learning, entertainments, etc. Or heavy duty handling, like photshops, video or music editing, gaming, apps developing, engineering drawing, designing jobs, etc. You can always find a right pc mini intel at this store.
Mini PC Office is an most and popular series designed for those who mainly run WPS, photoshops, PR, email, entertainments, etc. Sometimes, also call it as mini pc officeworks or home assistant mini pc.
Mini Gaming PC comes with higher level processors, like intel i3, i5, i7 10th, 11th or 12th; bigger memory and storage, like 16GB or 32GB ram, 512gb up to 1tb. Of course, rich slots support linking with two or more monitors or devices.
Except mini pc windows 11, there are also All In One PC , Student Laptop, Gaming Laptop , Android Tablet, Yoga Laptop , etc.
Mini PC Windows 11,High Performance Mini PC,Mini PC DDR4,PC Mini Intel
Henan Shuyi Electronics Co., Ltd. , https://www.shuyiaiopc.com