Circuit, method, and oximeter for indicating power supply by applying double-color light-emitting diode
A circuit, method, and oximeter for indicating a power supply by applying a double-color light-emitting diode (LED) are provided. The circuit, applied to a finger clip type pulse oximeter, comprises the following components: an MCU module, a double-color LED connected to the MCU module, a voltage measurement module connected to the MCU module, a rechargeable battery module connected to the voltage measurement module, and a power supply input module that is suitable for connection with an external power supply and is connected to the MCU module and the rechargeable battery module, wherein the MCU module is suitable for controlling the double-color LED according to the states of the power supply input module and the rechargeable battery module, so that the finger clip type pulse oximeter presents a visual result directly observable by the human eyes.
1 . A circuit, applied to a finger clip type pulse oximeter, for indicating a power supply by applying a double-color light-emitting diode (LED), characterized in that the circuit comprises:
a micro-controller unit (MCU) module;
a double-color LED module, including a double-color LED and connected to the MCU module;
a voltage measurement module connected to the MCU module;
a rechargeable battery module connected to the voltage measurement module; and
a power supply input module, which is suitable for connection with an external power supply and is connected to the MCU module and the rechargeable battery module;
wherein the MCU module is suitable for controlling the double-color LED according to the states of the power supply input module and the rechargeable battery module, so that the finger clip type pulse oximeter presents a visual result directly observable by the human eyes;
wherein the power supply input module comprises a socket and a fuse, and the fuse is connected to the socket;
wherein the circuit further comprises an insertion detection module, and the power supply input module is connected to the MCU module through the insertion detection module; and
wherein the insertion detection module comprises a first resistor, and the first resistor is directly connected between an input/output (I/O) pin of the MCU module and the fuse.
2 . An oximeter for indicating a power supply by applying a double-color LED, characterized in that: the oximeter, being of a finger clip type pulse oximeter, comprises a body and the circuit according to claim 1 ; the body is provided on a surface with a display screen and an indication position located on one side of the display screen, with the double-color LED set corresponding to the indication position.
3 . The circuit for indicating a power supply by applying a double-color LED according to claim 1 , wherein the power supply input module further comprises a first capacitor and a second capacitor, and the first capacitor and the second capacitor are connected in parallel; and one terminal of each of the first capacitor and second capacitor is grounded, and the other terminal of each of the first capacitor and the second capacitor is connected to an output terminal of the power supply input module.
4 . The circuit for indicating a power supply by applying a double-color LED according to claim 3 , wherein a capacitance of the first capacitor is 100 nano farads (nF), and a capacitance of the second capacitor is 10 micro farads (μF).
5 . The circuit for indicating a power supply by applying a double-color LED according to claim 1 , characterized in that: the rechargeable battery module comprises a lithium battery, and a charging management chip connected to an output terminal of the power supply input module; the lithium battery, with its negative electrode grounded, has its positive electrode connected to the charging management chip and connected to the MCU module through the voltage measurement module.
6 . The circuit for indicating a power supply by applying a double-color LED according to claim 5 , characterized in that: the charging management chip has a VIN pin connected to the power supply input module, a battery (BAT) pin connected to the lithium battery for charging current output, and a charging (CHG) pin connected to an indication LED for charging state output, the indication LED capable of exhibiting a third color.
7 . The circuit for indicating a power supply by applying a double-color LED according to claim 4 , characterized in that: the voltage measurement module comprises a second resistor and a third resistor, one terminal of the second resistor being connected to the positive electrode of the lithium battery; the third resistor has its one terminal grounded, and the other terminal connected to the other terminal of the second resistor and then connected to the MCU module.
8 . The circuit for indicating a power supply by applying a double-color LED according to claim 7 , wherein the second resistor has a resistance of 1.2 megaohms (MΩ) and the third resistor has a resistance of 200 kiloohms (KΩ).
9 . The circuit for indicating a power supply by applying a double-color LED according to claim 4 , characterized in that: the double-color LED D 1 comprises a first LED capable of exhibiting a first color, and a second LED capable of exhibiting a second color, with the first color different from the second color; the double-color LED module further comprises a fourth resistor and a fifth resistor; an anode of the first LED is connected to a voltage drain supply (VDD) pin of the MCU module through the fourth resistor, and an anode of the second LED is connected to the same VDD pin of the MCU module through the fifth resistor; a cathode of the first LED is directly connected to one I/O pin of the MCU module, and a cathode of the second LED is directly connected to the other I/O pin of the MCU module.
10 . The circuit for indicating a power supply by applying a double-color LED according to claim 9 , characterized in that:
the above description that the finger clip type pulse oximeter presents a visual result directly observable by the human eyes is specifically as follows:
when the power supply input module is connected to the external power supply, and the lithium battery is being charged, the MCU module controls the first LED to flash in the first color at a predetermined frequency;
when the power supply input module is connected to the external power supply, and the lithium battery is fully charged, the MCU module controls the first LED to be always on in the first color;
when the power supply input module is not connected to the external power supply, and the MCU module detects that the voltage of the detection terminal of the voltage measurement module is lower than a first predetermined voltage, the MCU module controls the second LED to be always on in the second color; and
when the power supply input module is not connected to the external power supply, and the MCU module detects that the voltage of the detection terminal of the voltage measurement module is lower than a second predetermined voltage, the MCU module controls the second LED to flash in the second color at a predetermined frequency;
wherein the second predetermined voltage is lower than the first predetermined voltage.
11 . A method, applied to a finger clip type pulse oximeter, for indicating a power supply by applying the circuit according to claim 1 , characterized in that the method is specifically as follows:
when the power supply input module is connected to the external power supply, and the lithium battery of the rechargeable battery module is being charged, the MCU module controls the first LED of the double-color LED to flash in the first color at a predetermined frequency;
when the power supply input module is connected to the external power supply, and the lithium battery of the rechargeable battery module is fully charged, the MCU module controls a first LED of the double-color LED to be always on in a first color;
when the power supply input module is not connected to the external power supply, and the MCU module detects that a voltage of a detection terminal of the voltage measurement module is lower than a first predetermined voltage, the MCU module controls a second LED of the double-color LED to be always on in a second color; and
when the power supply input module is not connected to the external power supply, and the MCU module detects that the voltage of the detection terminal of the voltage measurement module is lower than a second predetermined voltage, the MCU module controls the second LED of the double-color LED to flash in the second color at a predetermined frequency;
wherein the second predetermined voltage is lower than the first predetermined voltage.