Charging test circuit

Abstract

The utility model discloses a charging test circuit which comprises a power supply input interface DC1, a constant current control unit, a current detection unit, a display control unit, a display unit, a same interface CN1 and a grounding line GND, the power supply input interface DC1 is connected with an external power supply, the same interface CN1 is in butt joint with charging equipment, and the current detection unit is connected with the display control unit. The power input interface DC1 charges a charging device through the constant current control unit and the same interface CN1, the current detection unit detects the output voltage of a detected device through the same interface CN1, and the constant current control unit comprises a current controller U1 and a resistor R1. According to the utility model, by utilizing the setting mode of the charging test circuit, the same interface CN1 is used to realize charging and charging state indication of equipment connected to the interface, when charging is not carried out, the same interface CN1 is used to receive the output of the equipment to be tested, and whether the output voltage of the equipment is normal is displayed through a double-color LED to complete the test of the output state of the equipment.

Description

Technical Field

[0001] The utility model relates to the field of test circuits, in particular to a charging test circuit. Background Art

[0002] Charging refers to the process of replenishing or storing electrical energy in a battery or electronic device. In electronic devices, charging is usually performed by connecting to a power adapter or other charging device. The charging process mainly includes three stages: constant current charging, constant voltage charging, and cut-off charging. In the constant current charging stage, the charger will deliver electrical energy to the battery or device at a constant current. The current will gradually increase until it reaches the set maximum charging current. Once the battery or device reaches the set maximum charging voltage, the charger will keep the current constant at that voltage. The constant voltage charging stage is mainly to maintain the safety of the battery or device and prevent overcharging.

[0003] For special working scenarios, the circuit needs to charge the device through an interface and display whether the charging is completed. It also needs to use another interface to test whether the output voltage of the device is normal. The existing charging circuit can only complete the single charging function and cannot complete the test and charging status indication at the same time. It is not convenient to use the same charging interface to test whether the output voltage of the device is normal. Utility Model Content

[0004] The purpose of the utility model is to provide a charging test circuit to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a charging test circuit, the charging test circuit includes a power input interface DC1, a constant current control unit, a current detection unit, a display control unit, a display unit, a same interface CN1 and a ground line GND, the power input interface DC1 is connected to an external power supply, the same interface CN1 is connected to a charging device, the power input interface DC1 charges the charging device through the constant current control unit and the same interface CN1, and the current detection unit detects the output voltage of the device under test through the same interface CN1.

[0006] Preferably, the constant current control unit includes a current controller U1 and a resistor R1, the resistor R1 is connected to the current controller U1, pin 2 of the current controller U1 is connected to a ground line GND, and pin 3 of the current controller U1 is connected to a power input interface DC1.

[0007] Preferably, the current detection unit includes a transistor Q1, a resistor R2 and a resistor R3, the resistor R2 is connected between the same interface CN1 and the resistor R1, the transistor Q1 is connected to the resistor R2 and the resistor R3, the resistor R3 is connected in parallel with the resistor R2, and the transistor Q1 is connected to the display control unit.

[0008] Preferably, the display control includes a transistor Q2, a rectifier diode D1 and a resistor R5, the resistor R5 is connected between the transistor Q1 and the rectifier diode D1, the rectifier diode D1 is connected to the transistor Q2, one pin of the transistor Q2 is grounded, and the other pin of the transistor Q2 is connected to the display unit.

[0009] Preferably, the display unit includes a resistor R4, a resistor R6 and a bi-color LED, one end of the resistor R6 is connected to pin 1 of the current controller U1, pin 3 of the bi-color LED is connected to the transistor Q2, and the resistor R6 is connected between the bi-color LED and the transistor Q2 and pin 3 of the bi-color LED and the transistor Q2.

[0010] Preferably, pin 2 of the bicolor LED is grounded, pin 1 of the bicolor LED is connected to resistor R4, resistor R4 is connected to resistor R5 and transistor Q1, and transistor Q1, resistor R1 and resistor R2 are connected to resistor R6.

[0011] Technical effects and advantages of the utility model:

[0012] The utility model utilizes the setting mode of the charging test circuit, and the charging test circuit includes a power input interface DC1, a charging constant current control unit, a charging current detection unit, a display control unit, a charging state and device output display unit and the same interface CN1, so that the same interface CN1 is used to realize the charging and charging state indication of the device connected to the interface. When not charging, the same interface CN1 is used to receive the output of the device under test, and whether the output voltage of the device is normal is displayed by a two-color LED to complete the test of the output state of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a circuit block diagram of the utility model. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0015] The utility model provides Figure 1 A charging test circuit shown in the figure includes a charging test circuit including a power input interface DC1, a constant current control unit, a current detection unit, a display control unit, a display unit, a same interface CN1 and a ground line GND. The power input interface DC1 is connected to an external power supply, and the same interface CN1 is connected to a charging device. The power input interface DC1 charges the charging device through the constant current control unit and the same interface CN1. The current detection unit detects the output voltage of the device under test through the same interface CN1. The constant current control unit includes a current controller U1 and a resistor R1. The resistor R1 is connected to the current controller U1. Pin 2 of the current controller U1 is connected to the ground line GND. The current controller U1 Pin 3 is connected to the power input interface DC1. The principle of charging constant current control is to adjust the current in the charging circuit by using the current controller U1. The current controller U1 can adjust the current according to the feedback signal to keep it at a set constant value. The common current controller U1 includes a constant current source, a current sensor and a feedback loop. During the charging process, the current controller U1 adjusts the working state of the charging circuit in real time by monitoring the current of the charging battery. When the current of the charging battery is lower than the set constant current value, the current controller will increase the voltage output to increase the current in the charging circuit. When the current of the charging battery is higher than the set constant current value, the current controller will reduce the voltage output to reduce the current in the charging circuit.

[0016] When there is power input at the charging power input interface DC1, the same interface CN1 is connected to the device, and the charging power charges the device through the input interface DC1, the resistor R2 and the same interface CN1. When the voltage across R2 is greater than or equal to the conduction voltage of the transistor Q1, the transistor Q1 and the transistor Q2 are turned on. When the transistor Q2 is turned on, the 3rd pin of the bi-color LED enters the ground through the collector of the transistor Q2, and the green tube core of the bi-color LED goes out. At the same time, the current passes through the transistor Q1 and the resistor R4, the 1st pin of the bi-color LED enters the ground, and the red tube core of the bi-color LED goes out. The bicolor LED lights up and displays red, indicating that the circuit is charging the device. As the charging current decreases, when the voltage across the resistor R2 is less than the conduction voltage of the transistor Q1, the transistors Q1 and Q2 are cut off, and the charging power current passes through the input interface DC1, the current controller U1, the resistor R1, the resistor R6, and the 3rd pin of the bicolor LED into the ground. The green core of the bicolor LED lights up. At the same time, because the transistor Q1 is cut off, no current passes through the resistor R4, the red core of the bicolor LED goes out, and the bicolor LED displays green, indicating that the circuit has completed charging the device.

[0017] In particular, the current detection unit includes a transistor Q1, a resistor R2 and a resistor R3, the resistor R2 is connected between the same interface CN1 and the resistor R1, the transistor Q1 is connected to the resistor R2 and the resistor R3, the resistor R3 is connected in parallel with the resistor R2, the transistor Q1 is connected to the display control unit, when there is no power input to the charging power input interface DC1, the same interface CN1 is connected to the device, the circuit is in a test working state, when the device outputs voltage, due to the reverse bias of the transistor Q1, the transistor Q1 and the transistor Q2 are cut off, the current passes through the same interface CN1, the resistor R2, the resistor R6, and the 3rd pin of the two-color LED into the ground, and the green tube core of the two-color LED is lit, at the same time, due to the cut-off of the transistor Q1, no current passes through the resistor R4, the red tube core of the two-color LED is extinguished, and the two-color LED displays green, indicating that the output of the device is normal, realizing the test function, and thus the circuit uses one physical interface to complete the charging and testing functions.

[0018] Specifically, the display control includes a transistor Q2, a rectifier diode D1 and a resistor R5, the resistor R5 is connected between the transistor Q1 and the rectifier diode D1, the rectifier diode D1 is connected to the transistor Q2, one pin of the transistor Q2 is grounded, and the other pin of the transistor Q2 is connected to the display unit, the display unit includes a resistor R4, a resistor R6 and a bicolor LED, one end of the resistor R6 is connected to pin 1 of the current controller U1, pin 3 of the bicolor LED is connected to the transistor Q2, the resistor R6 is connected to the bicolor LED and the transistor Q2, and pin 3 of the bicolor LED is connected to the transistor Q2, pin 2 of the bi-color LED is grounded, pin 1 of the bi-color LED is connected to resistor R4, resistor R4 is connected to resistor R5 and transistor Q1, transistor Q1, resistor R1 and resistor R2 are connected to resistor R6, and by conducting the collectors of transistors Q1 and Q2, pin 1 or pin 3 of the bi-color LED can be changed to ground, thereby changing the lights of different colors of the bi-color LED to display its working status. The bi-color LED displays red, indicating that the circuit is charging the device positively, the red core of the bi-color LED is extinguished, and the bi-color LED displays green, indicating that the circuit has completed charging the device.

[0019] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A charging test circuit, characterized in that: The charging test circuit includes a power input interface DC1, a constant current control unit, a current detection unit, a display control unit, a display unit, a common interface CN1 and a ground line GND. The power input interface DC1 is connected to an external power supply, and the common interface CN1 is connected to a charging device. The power input interface DC1 charges the charging device through the constant current control unit and the common interface CN1, and the current detection unit detects the output voltage of the device under test through the common interface CN1.

2. A charging test circuit according to claim 1, characterized in that: The constant current control unit includes a current controller U1 and a resistor R1, wherein the resistor R1 is connected to the current controller U1, a pin 2 of the current controller U1 is connected to a ground line GND, and a pin 3 of the current controller U1 is connected to a power input interface DC1.

3. A charging test circuit according to claim 2, characterized in that: The current detection unit includes a transistor Q1, a resistor R2 and a resistor R3, wherein the resistor R2 is connected between the same interface CN1 and the resistor R1, the transistor Q1 is connected to the resistor R2 and the resistor R3, the resistor R3 is connected in parallel to the resistor R2, and the transistor Q1 is connected to the display control unit.

4. A charging test circuit according to claim 3, characterized in that: The display control includes a transistor Q2, a rectifier diode D1 and a resistor R5, wherein the resistor R5 is connected between the transistor Q1 and the rectifier diode D1, the rectifier diode D1 is connected to the transistor Q2, one pin of the transistor Q2 is grounded, and the other pin of the transistor Q2 is connected to the display unit.

5. A charging test circuit according to claim 4, characterized in that: The display unit includes a resistor R4, a resistor R6 and a bicolor LED, one end of the resistor R6 is connected to pin 1 of the current controller U1, pin 3 of the bicolor LED is connected to the transistor Q2, and the resistor R6 is connected between the bicolor LED and the transistor Q2 and pin 3 of the bicolor LED and the transistor Q2.

6. A charging test circuit according to claim 5, characterized in that: Pin 2 of the bicolor LED is grounded, pin 1 of the bicolor LED is connected to resistor R4, resistor R4 is connected to resistor R5 and transistor Q1, and transistor Q1, resistor R1 and resistor R2 are connected to resistor R6.

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