Output voltage indicating circuit

Abstract

The invention discloses an output voltage indicating circuit which is electrically connected with a power supply output end, and the power supply output end provides output voltage to the output voltage indicating circuit. The output voltage indicating circuit comprises a first detection unit which is electrically connected with the power supply output end and is configured to output a first signal when the output voltage is greater than or equal to a first voltage; the first control unit is electrically connected with the first detection unit and is configured to receive the first signal; the first light-emitting part is electrically connected with the first control unit, and the first control unit controls the first light-emitting part to be conducted or not conducted according to the first signal; the second detection unit is electrically connected with the power supply output end and is configured to output a second signal according to the output voltage; the second control unit is electrically connected with the second detection unit and is configured to receive the second signal; and the second light-emitting part is electrically connected with the second control unit, and the second control unit controls the second light-emitting part to be conducted or not conducted according to the second signal.

Description

Technical Field

[0001] This invention relates to an indicator circuit, and more particularly to an output voltage indicator circuit. Background Technology

[0002] PD3.1 is currently the highest standard for USB fast charging, providing output voltages of 5V, 9V, 15V, 20V, 28V, 36V, and 48V. Therefore, a USB PD 3.1 charger can provide different output voltages depending on the charging needs of various devices (such as smartphones, laptops, and IoT devices). However, to know the charger's current output voltage, users need to first check the charging voltage required by the device being charged. This lack of real-time output voltage information makes it difficult to effectively prevent accidents such as electric shock, resulting in lower safety. Summary of the Invention

[0003] To address the aforementioned technical problems, the present invention provides an output voltage indicating circuit electrically connected to a power output terminal. The power output terminal provides an output voltage to the output voltage indicating circuit. The output voltage indicating circuit includes a first detection unit, a first control unit, a first light-emitting element, a second detection unit, a second control unit, and a second light-emitting element. The first detection unit is electrically connected to the power output terminal and configured to output a first signal when the output voltage is greater than or equal to a first voltage. The first control unit is electrically connected to the first detection unit and configured to receive the first signal. The first light-emitting element is electrically connected to the first control unit. The first control unit controls the first light-emitting element to be turned on or off according to the first signal. The second detection unit is electrically connected to the power output terminal and configured to output a second signal according to the output voltage. The second control unit is electrically connected to the second detection unit and configured to receive the second signal. The second light-emitting element is electrically connected to the second control unit. The second control unit controls the second light-emitting element to be turned on or off according to the second signal.

[0004] In one embodiment, the first detection unit includes a first resistor, a Zener diode, and a second resistor. A first terminal of the first resistor is electrically connected to the power output terminal. The cathode of the Zener diode is electrically connected to a second terminal of the first resistor. The anode of the Zener diode is electrically connected to one end of the second resistor. A first node is provided between the Zener diode and the second resistor to output the first signal.

[0005] In one embodiment, the first control unit includes a switch connected in parallel with the first light-emitting element. When the first detection unit provides the first signal to the first control unit, the first signal turns the switch on, thereby turning off the first light-emitting element. When the output voltage is less than the first voltage, the switch turns off, thereby turning on the first light-emitting element.

[0006] In one embodiment, the first control unit includes a switch connected in series with the first light-emitting element. When the first detection unit provides the first signal to the first control unit, the first signal turns on the switch, thereby turning on the first light-emitting element. When the output voltage is less than the first voltage, the switch does not turn on, thereby turning off the first light-emitting element.

[0007] In one embodiment, the second control unit includes a first comparator. The positive and negative terminals of the first comparator receive the second signal and a reference voltage, respectively. The output of the first comparator is connected in series with the second light-emitting element. When the output voltage is greater than or equal to a second voltage, the voltage of the second signal is greater than the reference voltage, causing the output of the first comparator to provide a first turn-on signal to the second light-emitting element. The first turn-on signal turns on the second light-emitting element. The second voltage is less than the first voltage.

[0008] In one embodiment, the second detection unit includes a third resistor and a fourth resistor. A first terminal of the third resistor is electrically connected to the power output terminal. A second terminal of the third resistor is electrically connected to the first terminal of the fourth resistor. A second node is provided between the third resistor and the fourth resistor to output the second signal.

[0009] In one embodiment, the second detection unit further includes a fifth resistor, the first terminal of which is electrically connected to the second terminal of the fourth resistor. A third node is provided between the fourth resistor and the fifth resistor to output a third signal.

[0010] In one embodiment, the output voltage indication circuit further includes a third control unit and a third light-emitting element. The third control unit is electrically connected to the second detection unit and configured to receive the third signal. The third light-emitting element is electrically connected to the third control unit. The third control unit controls the second light-emitting element to be turned on or off according to the third signal.

[0011] In one embodiment, the third control unit includes a second comparator. The positive and negative terminals of the second comparator receive the third signal and a reference voltage, respectively. The output of the second comparator is connected in series with the third light-emitting element. When the output voltage is greater than or equal to the third voltage, the voltage of the third signal is greater than the reference voltage, causing the output of the second comparator to provide a second turn-on signal to the third light-emitting element. The second turn-on signal turns on the third light-emitting element. The third voltage is greater than the second voltage and less than the first voltage. Attached Figure Description

[0012] Figure 1 This is a circuit diagram of an output voltage indicator circuit according to an embodiment of the present invention;

[0013] Figure 2 This is a circuit diagram of an output voltage indicator circuit according to another embodiment of the present invention;

[0014] Wherein: 1. First detection unit; 10. First resistor; 101. First terminal of the first resistor; 102. Second terminal of the first resistor; 11. Zener diode; 110. Cathode of the Zener diode; 111. Anode of the Zener diode; 12. Second resistor; 121. One terminal of the second resistor; 130. First node; 2. First control unit; 21. Switch; 3. First light-emitting element; 4. Second detection unit; 40. Third resistor; 401. First terminal of the third resistor; 402. Second terminal of the third resistor; 41. Fourth resistor; 411. First terminal of the fourth resistor ; 412, the second end of the fourth resistor; 140, the second node; 42, the fifth resistor; 421, the first end of the fifth resistor; 150, the third node; 5, the second control unit; 51, the first comparator; 511, the positive terminal of the first comparator; 512, the negative terminal of the first comparator; 513, the output terminal of the first comparator; 6, the second light-emitting element; 7, the second comparator; 71, the second comparator; 711, the positive terminal of the second comparator; 712, the negative terminal of the second comparator; 713, the output terminal of the second comparator; 8, the third light-emitting element; 9, the power output terminal. Detailed Implementation

[0015] The various embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. The terms "first" and "second," etc., used in this disclosure are only used to distinguish different elements and parts and do not represent any order or importance.

[0016] Please see Figure 1The present invention provides an output voltage indicating circuit electrically connected to a power output terminal 9. The power output terminal 9 provides an output voltage to the output voltage indicating circuit. The output voltage indicating circuit includes a first detection unit 1, a first control unit 2, a first light-emitting element 3, a second detection unit 4, a second control unit 5, and a second light-emitting element 6.

[0017] The first detection unit 1 is electrically connected to the power output terminal 9 and configured to output a first signal when the output voltage is greater than or equal to a first voltage. The first control unit 2 is electrically connected to the first detection unit 1 and configured to receive the first signal. The first light-emitting element 3 is electrically connected to the first control unit 2. The first control unit 2 controls the first light-emitting element 3 to be turned on or off according to the first signal, so that the first light-emitting element 3 is in a bright or off state.

[0018] The second detection unit 4 is electrically connected to the power output terminal 9 and configured to output a second signal according to the output voltage. The second control unit 5 is electrically connected to the second detection unit 4 and configured to receive the second signal. The second light-emitting element 6 is electrically connected to the second control unit 5. The second control unit 5 controls the second light-emitting element 6 to be turned on or off according to the second signal, thereby making the second light-emitting element 6 in a bright or dark state.

[0019] In one embodiment, the first detection unit 1 includes a first resistor 10, a Zener diode 11, and a second resistor 12. The first terminal 101 of the first resistor 10 is electrically connected to the power output terminal 9. The cathode terminal 110 of the Zener diode 11 is electrically connected to the second terminal 102 of the first resistor 10. The anode terminal 111 of the Zener diode 11 is electrically connected to one terminal 121 of the second resistor 12. A first node 130 is formed between the Zener diode 11 and the second resistor 12 to output the first signal to the first control unit 2. Here, the first resistor 10 and the second resistor 12 are connected in series across the two ends of the Zener diode 11, respectively, to prevent excessive current flowing through the Zener diode 11 and damage to it.

[0020] In one embodiment, the first control unit 2 includes a switch 21 connected in parallel with the first light-emitting element 3. When the output voltage is greater than or equal to a first voltage, the first detection unit 1 provides the first signal to the first control unit 2, which turns on the switch 21, thus turning off the first light-emitting element 3. When the output voltage is less than the first voltage, the first detection unit 1 does not provide the first signal to the first control unit 2, causing the switch 21 to turn off and turning on the first light-emitting element 3. In another embodiment, the switch 21 may be connected in series with the first light-emitting element 3 (not shown). When the first detection unit 1 provides the first signal to the first control unit 2, the first signal turns on the switch 21, thus turning on the first light-emitting element 3. When the output voltage is less than the first voltage, the first detection unit 1 does not provide the first signal to the first control unit 2, causing the switch 21 to turn off and turning off the first light-emitting element 3. In this embodiment, the switch 21 may be an N-type MOSFET, and the first detection unit 1 is electrically connected to the gate of the N-type MOSFET, but is not limited thereto. In other embodiments, the switch 21 may also be a transistor.

[0021] In one embodiment, the second detection unit 4 includes a third resistor 40 and a fourth resistor 41. The first terminal 401 of the third resistor 40 is electrically connected to the power output terminal 9, and the second terminal 402 of the third resistor 40 is electrically connected to the first terminal 411 of the fourth resistor 41. A second node 140 is provided between the third resistor 40 and the fourth resistor 41 to output the second signal to the second control unit 5. The second detection unit 4 is used to divide the output voltage to form the second signal.

[0022] In one embodiment, the second control unit 5 includes a first comparator 51. The positive terminal 511 and the negative terminal 512 of the first comparator 51 receive the second signal and a reference voltage, respectively. The output terminal 513 of the first comparator 51 is connected in series with the second light-emitting element 6. When the output voltage is greater than or equal to a second voltage, the voltage of the second signal is greater than the reference voltage, causing the output terminal 513 of the first comparator 51 to provide a first turn-on signal to the second light-emitting element 6, which turns on the second light-emitting element 6. When the output voltage is less than the second voltage, the voltage of the second signal is less than the reference voltage, therefore the output terminal 513 of the first comparator 51 will not provide the first turn-on signal to the second light-emitting element 6, causing the second light-emitting element 6 to not turn on.

[0023] In one embodiment, the power output terminal 9 is the power output terminal of a USB PD 3.1 charger, capable of providing output voltages of 5V, 9V, 15V, 20V, 28V, 36V, and 48V. The first voltage and the second voltage can be any two output voltages, as long as the second voltage is less than the first voltage. For example, the first voltage can be set to 48V, and the second voltage can be set to 36V. The first light-emitting element 3 and the second light-emitting element 6 can be LEDs of different colors. For example, the first light-emitting element 3 can be a red LED, and the second light-emitting element 6 can be a green LED. When the output voltage is greater than or equal to the first voltage (48V), the first detection unit 1 provides the first signal to the first control unit 2, which turns on the switch 21, thus de-conducting the first light-emitting element 3 and preventing it from lighting up. When the output voltage is less than the first voltage (48V), the first signal is not provided to the first control unit 2, causing the switch 21 to de-conduct, thus turning on the first light-emitting element 3 and emitting red light. When the output voltage is greater than or equal to the second voltage (36V), the voltage of the second signal provided by the second detection unit 4 to the second control unit 5 is greater than the reference voltage, causing the first comparator 51 to provide the first turn-on signal to the second light-emitting element 6, thereby turning on the second light-emitting element 6 and emitting green light. When the output voltage is less than the second voltage (36V), the voltage of the second signal provided by the second detection unit 4 to the second control unit 5 is less than the reference voltage, therefore the first comparator 51 will not provide the first turn-on signal to the second light-emitting element 6, thereby turning off the second light-emitting element 6 and keeping it off. Thus, the output voltage indicating circuit can use different light colors to indicate different output voltages or their ranges, as shown in Table 1.

[0024] Output voltage First light-emitting element 3 Second light-emitting element 6 Indicator circuit illuminates color Below 28V Red light Not lit Red light 36V Red light Green light Huang Guang 48V Not lit Green light Green light

[0025] Table 1

[0026] See Figure 2 In one embodiment, the second detection unit 4 further includes a fifth resistor 42. A first terminal 421 of the fifth resistor 42 is electrically connected to a second terminal 412 of the fourth resistor 41. A third node 150 is provided between the fourth resistor 41 and the fifth resistor 42 to output a third signal. Further, the output voltage indication circuit also includes a third control unit 7 and a third light-emitting element 8. The third control unit 7 is electrically connected to the second detection unit 4 and configured to receive the third signal. The third light-emitting element 8 is electrically connected to the third control unit 7. The third control unit 7 controls the second light-emitting element 8 to be turned on or off according to the third signal.

[0027] In one embodiment, the third control unit 7 includes a second comparator 71. The positive terminal 711 and negative terminal 712 of the second comparator receive the third signal and a reference voltage, respectively. The output terminal 713 of the second comparator is connected in series with the third light-emitting element 8. When the output voltage is greater than or equal to the third voltage, the voltage of the third signal is greater than the reference voltage, causing the output terminal 713 of the second comparator 71 to provide a second turn-on signal to the third light-emitting element 8. The second turn-on signal turns on the third light-emitting element 8. When the output voltage is less than the third voltage, the voltage of the third signal is less than the reference voltage, therefore the output terminal 713 of the second comparator 71 will not provide the first turn-on signal to the third light-emitting element 8, causing the third light-emitting element 8 to not turn on. The third voltage is greater than the second voltage and less than the first voltage.

[0028] In one embodiment, the first voltage can be set to 48V, the second voltage can be set to 28V, and the third voltage can be set to 36V. The first light-emitting element 3 can be a red LED, the second light-emitting element 6 can be a green LED, and the third light-emitting element 8 can be a blue LED. The first light-emitting element 3 is not turned on and does not light up when the output voltage is greater than or equal to the first voltage (48V), and is turned on and emits red light when the output voltage is less than the first voltage (48V). The second light-emitting element 6 is turned on and emits green light when the output voltage is greater than or equal to the second voltage (28V), and is not turned on and does not light up when the output voltage is less than the second voltage (28V). The third light-emitting element 8 is turned on and emits blue light when the output voltage is greater than or equal to the third voltage (36V), and is not turned on and does not light up when the output voltage is less than the third voltage (36V). Thus, the output voltage indicating circuit can use more light-emitting colors to indicate different output voltages or their ranges, as shown in Table 2.

[0029] Output voltage First light-emitting element 3 Second light-emitting element 6 Third light-emitting element 8 Indicator circuit illuminates color Below 20V Red light Not lit Not lit Red light 28V Red light Green light Not lit Huang Guang 36V Red light Green light Blue light White light 48V Not lit Green light Blue light Blue light

[0030] Table 2

[0031] In one embodiment, the output voltage indication circuit may include multiple sets of "third control units 7 and third light-emitting elements 8," and the second detection unit 4 may include multiple fifth resistors 42, with a node between each pair of adjacent fifth resistors 42 for electrical connection to the corresponding third control unit 7. The working principle of this embodiment is as described above and will not be repeated here. Thus, the output voltage indication circuit can use more light-emitting colors to indicate different output voltages and / or their ranges.

[0032] In summary, the output voltage indicator circuit of the present invention can control the lighting or extinguishing of multiple light-emitting elements of different colors according to the magnitude of the output voltage, and can display different colored lights under different output voltages. That is, it can use different colored lights to indicate different output voltages, allowing users to understand the current output voltage of the charger in real time and intuitively, thereby effectively preventing accidents such as electric shock and improving safety.

[0033] The above embodiments are merely illustrative of the concept of the present invention. Those skilled in the art can modify the technical solutions in the foregoing embodiments, or make equivalent substitutions for one or more technical features, to achieve the same purpose and / or advantages as the foregoing embodiments, and such modifications or equivalent substitutions should all be included within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims

1. An output voltage indicating circuit, electrically connected to a power supply output terminal, wherein the power supply output terminal provides an output voltage to the output voltage indicating circuit, the output voltage indicating circuit comprising: A first detection unit is electrically connected to the power output terminal and configured to output a first signal when the output voltage is greater than or equal to a first voltage; A first control unit is electrically connected to the first detection unit and configured to receive the first signal; A first light-emitting element is electrically connected to the first control unit, and the first control unit controls the first light-emitting element to be turned on or off according to the first signal; A second detection unit is electrically connected to the power output terminal and configured to output a second signal according to the output voltage; A second control unit is electrically connected to the second detection unit and configured to receive the second signal; as well as A second light-emitting element is electrically connected to the second control unit, and the second control unit controls the second light-emitting element to be turned on or off according to the second signal.

2. The output voltage indication circuit as described in claim 1, characterized in that: The first detection unit includes a first resistor, a Zener diode, and a second resistor. The first end of the first resistor is electrically connected to the power output terminal. The cathode of the Zener diode is electrically connected to the second end of the first resistor. The anode of the Zener diode is electrically connected to one end of the second resistor. A first node is provided between the Zener diode and the second resistor to output the first signal.

3. The output voltage indication circuit as described in claim 1, characterized in that: The first control unit includes a switch connected in parallel with the first light-emitting element; when the first detection unit provides the first signal to the first control unit, the first signal turns on the switch, thereby turning off the first light-emitting element; when the output voltage is less than the first voltage, the switch turns off, thereby turning on the first light-emitting element.

4. The output voltage indication circuit as described in claim 1, characterized in that: The first control unit includes a switch connected in series with the first light-emitting element; when the first detection unit provides the first signal to the first control unit, the first signal turns on the switch, thereby turning on the first light-emitting element; when the output voltage is less than the first voltage, the switch does not turn on, thereby turning off the first light-emitting element.

5. The output voltage indication circuit as described in claim 1, characterized in that: The second control unit includes a first comparator, the positive terminal of the first comparator receiving the second signal and a reference voltage respectively, and the output terminal of the first comparator being connected in series with the second light-emitting element; when the output voltage is greater than or equal to a second voltage, the voltage of the second signal is greater than the reference voltage, so that the output terminal of the first comparator provides a first turn-on signal to the second light-emitting element, the first turn-on signal turning on the second light-emitting element, and the second voltage being less than the first voltage.

6. The output voltage indication circuit as described in claim 1, characterized in that: The second detection unit includes a third resistor and a fourth resistor. The first end of the third resistor is electrically connected to the power output terminal, and the second end of the third resistor is electrically connected to the first end of the fourth resistor. A second node is provided between the third resistor and the fourth resistor to output the second signal.

7. The output voltage indication circuit as described in claim 6, characterized in that: The second detection unit further includes a fifth resistor, the first end of which is electrically connected to the second end of the fourth resistor, and a third node between the fourth resistor and the fifth resistor to output a third signal.

8. The output voltage indication circuit as described in claim 7, characterized in that, Also includes: A third control unit, electrically connected to the second detection unit and configured to receive the third signal; and A third light-emitting element is electrically connected to the third control unit, and the third control unit controls the second light-emitting element to be turned on or off according to the third signal.

9. The output voltage indication circuit as described in claim 8, characterized in that: The third control unit includes a second comparator, the positive and negative terminals of which receive the third signal and a reference voltage, respectively. The output terminal of the second comparator is connected in series with the third light-emitting element. When the output voltage is greater than or equal to a third voltage, the voltage of the third signal is greater than the reference voltage, causing the output terminal of the second comparator to provide a second turn-on signal to the third light-emitting element. The second turn-on signal turns on the third light-emitting element. The third voltage is greater than the second voltage and less than the first voltage.

Images