Detection circuit of charger

Abstract

The utility model provides a detection circuit of a charger, which is used for detecting direct current output by the charger and comprises an indicating lamp. The first detection circuit is used for detecting whether the output voltage of the charger is higher than a set load voltage or not; the second detection circuit is used for detecting whether the output voltage of the charger is higher than a set control high voltage or not; the third detection circuit is used for detecting whether the output voltage of the charger is lower than a set control low voltage or not; a first switch is arranged in a power supply loop of the charger output for the first indicator lamp and the second indicator lamp, the on-off of the first switch is controlled by the first detection circuit, a second switch is arranged in a power supply loop of the second indicator lamp, and the on-off of the second switch is controlled by the second detection circuit. And the on-off of the second switch is controlled by the first detection circuit and the second detection circuit. According to the utility model, various possibilities are taken into consideration, the circuit is simple, devices are universal, economical and practical, the cost is low, dismounting and replacement are easy, and especially, whether normal aging occurs can be monitored clearly.

Description

Technical Field

[0001] The utility model relates to the field of charger detection, in particular to a detection circuit for chargers that detects chargers during the aging process in the production of chargers. Background Art

[0002] A charger, also known as a charging adapter, is a device for charging rechargeable batteries (secondary batteries). With the widespread application of mobile electronic devices, it has become an essential item in life. Chargers need to be aged before leaving the factory, and several indicators of the output voltage of the charger need to be detected during the aging process. The current aging equipment is expensive, increasing the cost of chargers and unable to meet the market demand. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a detection circuit for chargers that monitors the charging output voltage during the aging of chargers, which is economical, affordable, and meets the market demand.

[0004] The technical solution adopted by the utility model to achieve its technical purpose is: a detection circuit for chargers that detects the direct current output by the charger, including an indicator light.

[0005] The indicator light includes a first indicator light indicating that the charger is working with voltage output and a second indicator light indicating that the output voltage of the charger is too high or too low.

[0006] It also includes a first detection circuit for detecting whether the output voltage of the charger is higher than the set load voltage, a second detection circuit for detecting whether the output voltage of the charger is higher than the set control high voltage, and a third detection circuit for detecting whether the output voltage of the charger is lower than the set control low voltage.

[0007] In the power supply loop for the first indicator light and the second indicator light of the charger output, a first switch is provided, and the on / off of the first switch is controlled by the first detection circuit. A second switch is provided in the power supply loop of the second indicator light, and the on / off of the second switch is controlled by the second detection circuit and the second detection circuit.

[0008] Further, in the above detection circuit for chargers: the first indicator light is a green-light-emitting LED, and the second indicator light is a red-light-emitting LED.

[0009] Further, in the detection circuit of the above charger: the first switch is transistor Q1, and the second switch is transistor Q4; the emitter and collector of transistor Q1 are respectively connected to the voltage output terminal of the charger and the anodes of the green LED and the red LED. The cathode of the green LED is grounded, and the cathode of the red LED and the ground are respectively connected to the collector and emitter of transistor Q4; the base of transistor Q1 is connected to the output terminal of the first detection circuit, and the base of transistor Q4 is respectively connected to the output terminals of the second detection circuit and the second detection circuit.

[0010] Further, in the detection circuit of the above charger:

[0011] The first detection circuit includes comparator U2A. The voltage output terminal of the charger is connected to the “+” terminal of comparator U2A, the set on-load voltage signal is connected to the “-” terminal of comparator U2A, and the detection signal is taken from the output terminal of comparator U2A as the output terminal of the first detection circuit, and the effective output signal is high level;

[0012] The second detection circuit includes comparator U2B. The voltage output terminal of the charger is connected to the “+” terminal of comparator U2B, the set control high voltage signal is connected to the “-” terminal of comparator U2B, and the detection signal is taken from the output terminal of comparator U2B as the output terminal of the second detection circuit, and the effective output signal is low level;

[0013] The third detection circuit includes comparator U2C. The voltage output terminal of the charger is connected to the “-” terminal of comparator U2C, the set control low voltage signal is connected to the “+” terminal of comparator U2C, and the detection signal is taken from the output terminal of comparator U2C as the output terminal of the third detection circuit, and the effective output signal is low level;

[0014] At the voltage output terminal of the charger, it is connected to the comparator after passing through a voltage dividing circuit respectively. The on-load voltage signal, the control high voltage signal, and the control low voltage signal are also connected to the comparator after passing through the corresponding voltage dividing circuits.

[0015] Further, in the detection circuit of the above charger: the transistor Q1 is an NPN transistor, and a PNP transistor Q2 is also provided between the output terminal of the first detection circuit and the base of transistor Q1. The collector and emitter of transistor P2 are respectively connected to the base of transistor Q1 and the ground, and the output terminal of the first detection circuit is connected to the base of transistor Q2 after voltage division between the ground through resistors R7 and R6; the transistor Q4 is a PNP transistor, and the output terminals of the second detection circuit and the third detection circuit are respectively connected to the base of transistor Q4 after voltage division through resistors R10 and R12.

[0016] Further, in the detection circuit of the above charger: it further includes an anti-reverse connection diode D1, the cathode of the anti-reverse connection diode D1 is connected to the voltage output terminal of the charger, and the anode is grounded.

[0017] Further, in the detection circuit of the above charger: the nominal output of the voltage output terminal of the charger is 5VDC, and it further includes a DC / DC conversion circuit for converting 5VDC into 3.3VDC.

[0018] The present utility model considers various possibilities, has a simple circuit, common components, is economical and affordable, has a low cost, is easy to disassemble and replace, and is especially clear at a glance for monitoring whether it is aging normally.

[0019] The present utility model uses a comparator and a triode to form an intelligent control circuit, comprehensively considers various possible situations, and monitors whether the charger or adapter is aging normally by observing the change of the LED indicator.

[0020] The following further describes the present utility model in conjunction with the accompanying drawings and specific embodiments. Description of the Drawings

[0021] Attached Figure 1 is the schematic diagram of the detection circuit of the charger in Embodiment 1 of the present utility model. Specific Embodiments

[0022] This embodiment is a charger detection circuit, which intuitively displays the relevant indicators of the charger. Using this detection circuit, the voltage division multiple of the voltage division circuit can be adjusted according to the different nominal output voltages of the charger, and different chargers can be detected, especially during the aging process of the charger. For example Figure 1 As shown, it is a monitoring circuit used when a charger with an output voltage of 5VDC is aging. Observed by the indicator light, the specific output of this charger is: 4.7 - 5.3VDC is the normal output, when it is higher than 5.3VDC and lower than 4.7VDC, the red light is on, only when it is between 4.7 - 5.3VDC, the green light is on only, but when the output voltage of the charger is lower than 4.5VDC, it means it is lower than the load-carrying voltage and both lights are off. Therefore, in this embodiment, three detection circuits are adopted, namely the first detection circuit for detecting whether the output voltage of the charger is higher than the load-carrying voltage (4.5VDC), the third detection circuit for detecting whether the output voltage of the charger is lower than the control low voltage (4.7VDC), and the third detection circuit for detecting whether the output voltage of the charger is higher than the control high voltage (5.3VDC). The structures of these three detection circuits are basically the same. As Figure 1 shown, they are all compared with the corresponding set signals. When the output voltage of the charger reaches the corresponding set value, the comparator flips to control whether the indicator light is lit.

[0023] Such asFigure 1 As shown: In this embodiment, a detection circuit of a charger is provided to detect the direct current output by the charger, including an indicator light; the indicator light includes a first indicator light indicating that the charger is working and has a voltage output, and a second indicator light indicating that the output voltage of the charger is too high or too low; in this embodiment, the first indicator light is a green-light-emitting LED, and the second indicator light is a red-light-emitting LED.

[0024] In the power supply loop for supplying power to the green-light LED and the red-light LED of the charger output, a first switch is provided. This switch is an electronic switch. In this embodiment, an NPN triode Q1 is used. The base of the triode Q1 is controlled by a first detection circuit. A second switch is provided in the power supply loop of the red-light LED. In this embodiment, the second switch selects a PNP triode Q4. The base of the triode Q4 is controlled by a second detection circuit and a second detection circuit. In this embodiment, the status is indicated by red and green lights. If the output voltage of the charger is lower than 4.5VDC, no light is on. If it is lower than 4.7VDC and higher than 4.5VDC, both the red light and the green light are on. If the output voltage of the charger is between 4.7 - 5.3VDC, only the green light is on. When the output voltage of the charger is higher than 5.3VDC, both the red light and the green light are on.

[0025] As Figure 1 shown, in this embodiment, the specific connection method is: the first switch is the triode Q1, and the second switch is the triode Q4; the emitter and collector of the triode Q1 are respectively connected to the voltage output terminal of the charger and the anodes of the green-light LED and the red-light LED. The cathode of the green-light LED is grounded. The cathode of the red-light LED and the ground are respectively connected to the collector and emitter of the triode Q4; the base of the triode Q1 is connected to the output terminal of the first detection circuit, and the base of the triode Q4 is respectively connected to the output terminals of the second detection circuit and the second detection circuit

[0026] The first detection circuit includes a comparator U2A. The voltage output terminal of the charger is connected to the “+” terminal of the comparator U2A. The set loaded voltage signal is connected to the “-” terminal of the comparator U2A. The detection signal is taken from the output terminal of the comparator U2A as the output terminal of the first detection circuit, and the effective output signal is a high level;

[0027] The second detection circuit includes a comparator U2B. The voltage output terminal of the charger is connected to the “+” terminal of the comparator U2B. The set control high voltage signal is connected to the “-” terminal of the comparator U2B. The detection signal is taken from the output terminal of the comparator U2B as the output terminal of the second detection circuit, and the effective output signal is a low level;

[0028] The third detection circuit includes a comparator U2C. The voltage output terminal of the charger is connected to the "-" terminal of the comparator U2C, the set control low voltage signal is connected to the "+" terminal of the comparator U2C, and the detection signal is taken from the output terminal of the comparator U2C as the output terminal of the third detection circuit, and the effective output signal is at a low level;

[0029] At the voltage output terminal of the charger, it is also connected to the comparator after passing through a voltage dividing circuit respectively. The loaded voltage signal, the control high voltage signal, and the control low voltage signal are also connected to the comparator after passing through the corresponding voltage dividing circuits. In this embodiment, the loaded voltage signal, the control high voltage signal, and the control low voltage signal are 4.5VDC, 4.7VDC, and 5.3VDC respectively, and can be set according to the specifications of the charger in practice, or these set voltages can be set by adjusting the voltage dividing resistors. There are 4 voltage dividing circuits in this embodiment. Three voltage dividing circuits are used to divide the output voltage of the charger, and the other voltage dividing circuit divides the 3.3VDC standard voltage and compares it with the charger output voltage after being divided in the same way.

[0030] In this embodiment, the triode Q1 is an NPN triode, and a PNP triode Q2 is also provided between the output terminal of the first detection circuit and the base of the triode Q1. The collector and emitter of the triode P2 are connected to the base of the triode Q1 and the ground respectively. The output terminal of the first detection circuit is connected to the base of the triode Q2 after voltage division with the ground through the resistors R7 and R6; the triode Q4 is a PNP triode, and the output terminals of the second detection circuit and the third detection circuit are connected to the base of the triode Q4 after voltage division through the resistors R10 and R12 respectively.

[0031] In this embodiment, it also includes an anti-reverse connection diode D1. The cathode of the anti-reverse connection diode D1 is connected to the voltage output terminal of the charger, and the anode is grounded. At this time, if it is inserted reversely, it will return through the cathode of the diode D1 and will not enter the circuit.

[0032] In addition, in this embodiment, it also includes a DC / DC conversion circuit for converting 5VDC to 3.3VDC. As Figure 1 shown, this circuit includes a triode Q3 and a voltage regulator U1. The model of the voltage regulator U1 is TL_341, and by adjusting the resistance values of the resistors R16 and R11, a stable 3.3VDC can be output from the emitter of the triode.

Claims

1. A detection circuit for a charger, which detects the direct current output by the charger and includes an indicator light; characterized in that: The indicator light includes a first indicator light indicating that the charger is working with voltage output and a second indicator light indicating that the output voltage of the charger is too high or too low; It further includes a first detection circuit for detecting whether the output voltage of the charger is higher than the set on-load voltage, a second detection circuit for detecting whether the output voltage of the charger is higher than the set control high voltage, and a third detection circuit for detecting whether the output voltage of the charger is lower than the set control low voltage; In the power supply loop for the first indicator light and the second indicator light when the charger outputs, a first switch is provided, and the on / off of the first switch is controlled by the first detection circuit. A second switch is provided in the power supply loop of the second indicator light, and the on / off of the second switch is controlled by the second detection circuit and the second detection circuit.

2. The detection circuit of the charger according to claim 1, wherein: The first indicator light is a green-light-emitting LED, and the second indicator light is a red-light-emitting LED.

3. The detection circuit of the charger according to claim 2, wherein: The first switch is a triode Q1, and the second switch is a triode Q4; the emitter and collector of the triode Q1 are respectively connected to the voltage output terminal of the charger and the anodes of the green LED and the red LED. The cathode of the green LED is grounded, and the cathode of the red LED and the ground are respectively connected to the collector and emitter of the triode Q4; the base of the triode Q1 is connected to the output terminal of the first detection circuit, and the base of the triode Q4 is respectively connected to the output terminals of the second detection circuit and the second detection circuit.

4. The detection circuit for a charger according to claim 3, characterized in that: The first detection circuit includes a comparator U2A. The voltage output terminal of the charger is connected to the "+” terminal of the comparator U2A, the set on-load voltage signal is connected to the "-” terminal of the comparator U2A, and the detection signal is the output signal of the comparator U2A as the output terminal of the first detection circuit, and the effective output signal is a high level; The second detection circuit includes a comparator U2B. The voltage output terminal of the charger is connected to the "+” terminal of the comparator U2B, the set control high voltage signal is connected to the "-” terminal of the comparator U2B, and the detection signal is the output signal of the comparator U2B as the output terminal of the second detection circuit, and the effective output signal is a low level; The third detection circuit includes a comparator U2C. The voltage output terminal of the charger is connected to the "-” terminal of the comparator U2C, the set control low voltage signal is connected to the "+” terminal of the comparator U2C, and the detection signal is the output signal of the comparator U2C as the output terminal of the third detection circuit, and the effective output signal is a low level; The voltage output terminal of the charger is also connected to the comparator after passing through a voltage division circuit respectively. The on-load voltage signal, the control high voltage signal, and the control low voltage signal are also connected to the comparator after passing through the corresponding voltage division circuits.

5. The detection circuit of the charger according to claim 4, characterized in that: The transistor Q1 is an NPN transistor, and a PNP transistor Q2 is further arranged between the output end of the first detection circuit and the base of the transistor Q1. The collector and emitter of the transistor P2 are respectively connected to the base of the transistor Q1 and the ground. The output end of the first detection circuit is connected to the base of the transistor Q2 after voltage division with the ground through a resistor R7 and a resistor R6. The transistor Q4 is a PNP transistor, and the output ends of the second detection circuit and the third detection circuit are respectively connected to the base of the transistor Q4 after voltage division through a resistor R10 and a resistor R12.

6. The detection circuit of the charger according to any one of claims 1 to 5, characterized in that: It further includes an anti-reverse connection diode D1. The cathode of the anti-reverse connection diode D1 is connected to the voltage output end of the charger, and the anode is grounded.

7. The detection circuit of the charger according to claim 6, characterized in that: The nominal output of the voltage output end of the charger is 5VDC, and it further includes a DC / DC conversion circuit for converting 5VDC into 3.3VDC.

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