CN212379536U

CN212379536U - Power supply power failure detection circuit

Info

Publication number: CN212379536U
Application number: CN202020411267.0U
Authority: CN
Inventors: 郑德华; 陈耿圳
Original assignee: Zhuhai Shengchang Electronics Co ltd
Current assignee: Zhuhai Shengchang Electronics Co ltd
Priority date: 2020-03-26
Filing date: 2020-03-26
Publication date: 2021-01-19
Anticipated expiration: 2030-03-26

Abstract

The utility model provides a power failure detection circuit, which comprises a power supply circuit, a power failure detection circuit and a singlechip circuit; the power supply circuit comprises a power supply main circuit and a voltage reduction circuit, wherein the input end of the power supply main circuit is connected with commercial power, and the output end of the power supply main circuit is connected with the voltage reduction circuit; the output ends of the power main circuit and the voltage reduction circuit are grounded through a capacitor C1 and a capacitor C2 respectively; the power failure detection circuit comprises a voltage stabilizing diode Z1, a resistor R1, a resistor R2 and a power switch device, wherein the negative electrode of the voltage stabilizing diode Z1 is connected with the output end of the main circuit of the power supply, and the positive electrode of the voltage stabilizing diode Z1 is connected with the control end of the power switch device through a resistor R1; the high-level end of the power switch device is connected with the output end of the voltage reduction circuit through a resistor R2, and the low-level end of the power switch device is grounded; the signal receiving end of the single chip microcomputer circuit is connected with the high-level end of the power switch device, and the power end of the single chip microcomputer is connected with the output end of the voltage reduction circuit on one hand and connected with the ground through a capacitor C3 on the other hand. The circuit can perform data storage or protection actions before the power supply is completely powered off.

Description

Power supply power failure detection circuit

Technical Field

The utility model relates to an electronic circuit technical field especially relates to a power failure detection circuit.

Background

With the increase of electronic equipment, the load capacity of a power grid is greatly improved. When the power grid fluctuates or power failure occurs, the subsequent working circuit is abnormally powered off, so that on one hand, data cannot be stored in time, data loss is caused, and huge loss can be brought to customers; on the other hand, no protection measures are taken in abnormal power failure, so that a working circuit is easily damaged, and unnecessary burden of a client is increased.

With the increasing maturity of semiconductor technology, semiconductor devices play an important role in the whole circuit, and are sensitive to voltage and current, and abnormal grid fluctuation or power failure can cause damage to the semiconductor devices and even cause the whole circuit to fail. For example, with the rapid development of the LED lighting industry, LEDs are installed in all households and outdoor lighting, so that the LED power supply market is developed vigorously, and the requirements on the LED power supply are higher and higher. The LED power supply belongs to a semiconductor device, is sensitive to voltage and current abnormity, and particularly can cause power grid fluctuation and even power failure in places with severe power consumption environments, so that the LED power supply is abnormally powered off, data is lost or the LED power supply is damaged. Therefore, it is necessary to develop a power failure detection circuit.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem that a follow-up working circuit cannot timely store data or cannot perform corresponding protection actions due to abnormal power failure of a power grid, the application provides a power supply power failure detection circuit, which has the following specific implementation mode:

a power failure detection circuit comprises a power supply circuit, a power failure detection circuit and a single chip circuit;

the power supply circuit comprises a power supply main circuit and a voltage reduction circuit, wherein the input end of the power supply main circuit is respectively connected with a live line L and a zero line N, and the output end of the power supply main circuit is connected with the input end of the voltage reduction circuit; the output ends of the power supply main circuit and the voltage reduction circuit are grounded through a capacitor C1 and a capacitor C2 respectively;

the power failure detection circuit comprises a voltage stabilizing diode Z1, a resistor R1, a resistor R2 and a power switch device; the negative electrode of the voltage-stabilizing diode Z1 is connected with the output end of the power supply main circuit, and the positive electrode of the voltage-stabilizing diode Z1 is connected with the control end of the power switch device through a resistor R1; the high-level end of the power switch device is connected with the output end of the voltage reduction circuit through a resistor R2, and the low-level end of the power switch device is grounded;

the single-chip microcomputer circuit comprises a single-chip microcomputer and a capacitor C3, a signal receiving end of the single-chip microcomputer is connected with a high-level end of the power switch device, and a power supply end of the single-chip microcomputer is connected with an output end of the voltage reduction circuit on one hand and is connected with the ground through the capacitor C3 on the other hand.

In one or more embodiments of the present invention, the power switch device is an NPN transistor or an NMOS transistor.

In one or more embodiments of the utility model, the step-down circuit adopts LDO step-down chip, the input of LDO step-down chip with the output of power main circuit is connected, the output is connected with the power end of singlechip, low-voltage end ground connection.

In one or more embodiments of the present invention, the LDO buck chip is a 78L33 model.

In one or more embodiments of the present invention, the single chip microcomputer is a chip whose model is STM32G030F6P 6.

The utility model discloses the beneficial implementation effect who brings is: after the power failure detection circuit and the single chip circuit are adopted, when the input mains supply of the power main circuit is in power failure, the power failure detection circuit can transmit a detected power failure signal to the single chip circuit, after the single chip circuit detects the power failure signal, the data is stored and other protection actions are carried out before the power supply is completely powered off, and after the power main circuit is powered on again, the data before the power failure is read, and normal operation is recovered. The power failure detection circuit has the advantages of ingenious design concept, simple structure, sensitive response and low cost, can effectively avoid data loss after abnormal power failure and reduce loss caused by data loss, and also reduces the damage probability of a working circuit due to the fact that a power failure protection mechanism is made in advance.

Drawings

Fig. 1 is a functional block diagram of a power failure detection circuit disclosed in the present invention;

fig. 2 is a circuit diagram of a power failure detection circuit disclosed in the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail with reference to the accompanying drawings 1-2 and the embodiments:

a power failure detection circuit comprises a power supply circuit 10, a power failure detection circuit 20 and a singlechip circuit 30; the power supply circuit 10 comprises a power supply main circuit 101 and a voltage reduction circuit, wherein the input end of the power supply main circuit 101 is respectively connected with a live line L and a zero line N, the output end of the power supply main circuit 101 outputs a first voltage VCC, the first voltage VCC is connected with the input end of the voltage reduction circuit, and the output end of the voltage reduction circuit outputs a second voltage VDD; the output ends of the power supply main circuit 101 and the voltage reduction circuit are grounded through a capacitor C1 and a capacitor C2 respectively; for driving the LED light source circuit, preferably, the voltage reduction circuit employs an LDO voltage reduction chip U1, an input end of the LDO voltage reduction chip U1 is connected to the first voltage VCC, an output end of the LDO voltage reduction chip outputs the second voltage VDD, and a low voltage end of the LDO voltage reduction chip is grounded. The power failure detection circuit 20 comprises a voltage stabilizing diode Z1, a resistor R1, a resistor R2 and a power switch device, wherein in order to simplify the circuit structure, the power switch device preferably adopts an NPN triode Q1 (an NMOS transistor can be selected), the negative electrode of the voltage stabilizing diode Z1 is connected with a first voltage VCC, the positive electrode of the voltage stabilizing diode Z1 is connected with the base level of the NPN triode Q1 through a resistor R1, the collector electrode of the NPN triode Q1 is connected with a second voltage VDD through a resistor R2, and the emitter is grounded; the single chip microcomputer circuit 30 comprises a single chip microcomputer chip U2 and a capacitor C3, a signal receiving end of the single chip microcomputer chip U2 is connected with a collector of an NPN triode Q1, a power supply end of the single chip microcomputer chip U2 is connected with a second voltage VDD on one hand, and is connected with the ground through the capacitor C3 on the other hand, and a grounding end of the single chip microcomputer chip U2 is grounded.

The working principle of the power failure detection circuit is explained as follows:

after the commercial power is processed by the power main circuit 101, the output end of the power main circuit 101 outputs a first voltage VCC, the first voltage VCC stores the voltage through filtering by the capacitor C1, the voltage is reduced by the LDO voltage reduction chip U1 to a required second voltage VDD, and the second voltage VDD stores the voltage through filtering by the capacitor C2. Since the first voltage VCC is greater than the conduction threshold of the zener diode Z1, the zener diode Z1 is turned on, the first voltage VCC turns on the NPN transistor Q1 through the resistor R1, and the collector of the NPN transistor Q1 has a low voltage, so that the NPN transistor Q1 pulls the voltage at the signal receiving terminal of the monolithic chip U2 down to 0V. When the input mains supply of the LED power supply is powered off, the voltage stored in the capacitor C1 starts to be powered off, and when the voltage of the capacitor C1 is lower than the conduction threshold of the zener diode Z1, no voltage passes through the resistor R1 to the NPN transistor Q1, so that the NPN transistor Q1 is in an off state. Because the capacitor C2 stores the voltage of the second voltage VDD, the second voltage VDD is input to the signal receiving terminal of the single chip microcomputer chip U2 through the resistor R2, and after the single chip microcomputer chip U2 detects the power-down signal, the data is stored before the power of the LED power supply is not completely turned off, and other protection actions are performed. When the input mains supply of the LED power supply is powered down, the power-down detection circuit 20 will quickly detect a power-down signal, and then transmit the power-down signal to the single chip circuit 30, and store data and perform other protection actions before the LED power supply is completely powered down. And after the LED power supply is powered on again, reading the data before power failure, and recovering normal operation.

Of course, the above scheme only uses the LED light source as a specific embodiment, and the power failure detection circuit can also be applied to power failure detection and protection of other working circuits.

The above-mentioned embodiments are merely the best embodiments of the present invention, and are not the only solutions, and are not limited to the above-mentioned embodiments, so long as the technical effects of the present invention are achieved by any of the same or similar means, all should fall within the protection scope of the present invention.

Claims

1. A power failure detection circuit is characterized in that: the power failure detection circuit comprises a power supply circuit, a power failure detection circuit and a singlechip circuit;

2. The power down detection circuit of claim 1, wherein: the power switch device adopts an NPN triode or an NMOS transistor.

3. The power down detection circuit of claim 1, wherein: the voltage reduction circuit adopts an LDO voltage reduction chip, the input end of the LDO voltage reduction chip is connected with the output end of the power main circuit, the output end of the LDO voltage reduction chip is connected with the power supply end of the single chip microcomputer, and the low-voltage end of the LDO voltage reduction chip is grounded.

4. The power down detection circuit of claim 3, wherein: the LDO step-down chip is 78L 33.

5. The power down detection circuit of any of claims 1-3, wherein: the single chip microcomputer adopts a chip with the model of STM32G030F6P 6.