TWI732399B - Charge apparatus - Google Patents

Abstract

A charge apparatus is provided. A detection circuit includes a voltage dividing path between an output of a charging circuit and an output of a reference voltage generating circuit. The detecting circuit provides a detection signal according to a divided voltage on the voltage dividing path. A control circuit determines whether a load is connected to the charging apparatus according to the detection signal.

Description

Charging device

The present invention relates to an electronic device, and particularly relates to a charging device.

The power of the portable electronic device is usually provided by the rechargeable power storage device, so the use time of the portable electronic device depends on the power storage capacity of the rechargeable power storage device. In addition, the rechargeable power storage device must be used with a charging device. Among them, the charging device can not only boost the power of the rechargeable power storage device in a timely manner, but also can detect whether the portable electronic device is connected to the rechargeable power storage device, and determine whether the portable electronic device needs to be charged.

Traditional charging devices can, for example, use Hall sensing, design mechanical switches, or use pogo pins to detect the connection of a portable electronic device and determine whether to charge or not. However, these methods will be bulky. Shortcomings such as excessive size, high cost, easy damage to the mechanical structure, poor waterproof and dustproof effect, and the need for additional pins.

The invention provides a charging device, which can improve the disadvantages of the traditional charging device such as large volume, high cost, easy damage to the mechanical structure, poor waterproof and dustproof effect, and the need for additional pins.

The charging device of the present invention includes a power supply, a charging circuit, a reference voltage generating circuit, a detection circuit and a control circuit. The charging circuit is coupled to the power source and provides a charging voltage according to the power source. The reference voltage generating circuit is coupled to the power source and provides a reference voltage according to the power source. The detecting circuit is coupled to the charging circuit and the reference voltage generating circuit. The detecting circuit includes a voltage dividing path between the output terminal of the charging circuit and the output terminal of the reference voltage generating circuit. The detecting circuit is based on the divided voltage on the voltage dividing path. Provide detection signal. The control circuit is coupled to the reference voltage generation circuit, the detection circuit and the charging circuit, and determines whether the load is connected to the charging device according to the detection signal and the charging current of the charging circuit.

In an embodiment of the present invention, the above-mentioned control circuit also judges the charging state of the load according to the charging current of the charging circuit.

In an embodiment of the present invention, the aforementioned detection circuit includes a diode, a resistor, a voltage divider circuit, and a comparator. The anode of the diode is coupled to the output terminal of the reference voltage generating circuit. The resistor is coupled between the cathode of the diode and the output terminal of the charging circuit. The voltage divider circuit is coupled to the common junction of the diode and the resistor, and divides the voltage on the common junction of the diode and the resistor to generate a divided voltage. The positive and negative input terminals of the comparator are respectively coupled to the output terminals of the voltage dividing circuit and the charging circuit, and compare the divided voltage with the charging voltage to generate a detection signal.

In an embodiment of the present invention, the aforementioned voltage divider circuit includes a first resistor and a second resistor. The second resistor and the first resistor are connected in series between the common connection point of the diode and the resistor and the ground. The common connection point of the first resistor and the second resistor is coupled to the positive input terminal of the comparator.

In an embodiment of the present invention, the aforementioned detection circuit includes a first resistor and a diode. The first end of the first resistor is coupled to the reference voltage generating circuit. The anode and the cathode of the diode are respectively coupled to the second end of the first resistor and the output end of the charging circuit. The load has a second resistor, and the common contact of the first resistor and the diode generates a detection signal. When the load is connected to the charging device, the second resistor is coupled between the cathode of the diode and the ground.

In an embodiment of the present invention, when the control circuit determines that the load is not connected to the charging device according to the detection signal, the control circuit controls the charging circuit to stop outputting the charging voltage.

In an embodiment of the present invention, when the control circuit determines that the load is connected to the charging device according to the detection signal and the charging current and the load has not been fully charged, the control circuit controls the charging circuit to output a charging voltage to charge the load.

In an embodiment of the present invention, when the control circuit determines that the load is connected to the charging device and the load has been charged according to the detection signal and the charging current, the control circuit controls the charging circuit to stop outputting the charging voltage.

In an embodiment of the present invention, the above-mentioned charging circuit includes a voltage conversion circuit and a current sensing circuit. The voltage conversion circuit is coupled to the control circuit and converts the voltage provided by the power supply to generate a charging voltage. The current sensing circuit is coupled to the voltage conversion circuit and the control circuit, senses the charging current, and transmits the sensing result to the control circuit.

In an embodiment of the present invention, the aforementioned charging voltage is greater than the reference voltage.

Based on the above, the detection circuit of the embodiment of the present invention can provide a detection signal according to the divided voltage on the divided voltage path between the output terminal of the charging circuit and the output terminal of the reference voltage generating circuit, and the control circuit judges according to the detection signal Whether the load is connected to the charging device. In this way, there is no need to use magnets, mechanical switches, or additional spring pin pins to detect whether the load is connected to the charging device, and it can effectively improve the large size, high cost, and easy damage of the mechanical structure of the traditional charging device. Shortcomings such as poor waterproof and dustproof effects and the need for additional pins.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, the following specific embodiments are described in detail in conjunction with the accompanying drawings.

FIG. 1 is a schematic diagram of a charging device according to an embodiment of the present invention, please refer to FIG. 1. The charging device 100 includes a power supply 102, a charging circuit 104, a reference voltage generation circuit 106, a detection circuit 108, and a control circuit 110. The power supply 102 is coupled to the charging circuit 104 and the reference voltage generation circuit 106, and the detection circuit 108 is coupled to the reference voltage generation circuit 106 and the output terminal of the charging circuit 104. The control circuit 110 is coupled to the charging circuit 104, the reference voltage generating circuit 106 and the detection circuit 108. To keep the diagram concise, the coupling of the control circuit 110 and the charging circuit 104 is not shown in FIG. Connection relationship.

The charging circuit 104 can provide a charging voltage V1 according to the power supply 102. The reference voltage generating circuit 106 generates a reference voltage at its output terminal according to the power supply 102. The detection circuit 108 includes a voltage dividing path between the output terminal of the charging circuit 104 and the output terminal of the reference voltage generating circuit 106. The detecting circuit 108 can provide a detection signal S1 according to the divided voltage on the voltage dividing path, and the control circuit 110 can determine whether the load RL is connected to the charging device 100 according to the detection signal S1. The load RL can be a portable electronic device such as a wireless earphone, a power bank, a smart bracelet, or a smart watch, but is not limited thereto. In addition, the control circuit 110 can also determine the charging state of the load according to the charging current I1 of the charging circuit 104 to determine whether to charge the load RL.

For example, when the control circuit 110 determines that the load RL is not connected to the charging device 100 according to the detection signal S1, the control circuit 110 can control the charging circuit 104 to stop outputting the charging voltage V1. When the control circuit 110 determines that the load RL is connected to the charging device 100 according to the detection signal S1 and the charging current I1 and the load RL has not yet been charged (for example, when the charging current I1 is greater than the preset current value, the control circuit 110 may determine that the load RL has not been completed Charging), the control circuit 110 can control the charging circuit 104 to output a charging voltage V1 to charge the load RL. In addition, when the control circuit 110 determines that the load RL is connected to the charging device 100 according to the detection signal S1 and the charging current I1 and the load RL has been charged (for example, when the charging current I1 is less than or equal to the preset current value, the control circuit 110 may determine The load RL has been charged), the control circuit 110 controls the charging circuit 104 to stop outputting the charging voltage V1.

In this way, the detection circuit 108 provides the detection signal S1 according to the divided voltage on the divided voltage path between the output terminal of the charging circuit 104 and the output terminal of the reference voltage generating circuit 106, and the control circuit 110 detects according to The signal S1 determines whether the load RL is connected to the charging device 100 and determines whether to charge the load RL according to the charging current I1 of the charging circuit 104. The load RL can be realized without magnets, mechanical switches or additional components such as spring pins. The detection of whether it is connected to the charging device 100 can effectively improve the disadvantages of the traditional charging device such as large size, high cost, easy damage to the mechanical structure, poor waterproof and dustproof effect, and the need for additional pins.

2 is a schematic diagram of a charging device according to another embodiment of the present invention. FIG. 3 is a schematic diagram of a charging process of a charging device according to an embodiment of the present invention. Please refer to FIGS. 2 and 3. In the embodiment of FIG. 2, the charging circuit 104 may include a voltage conversion circuit 202 and a current sensing circuit 204, wherein the voltage conversion circuit 202 is coupled to the power supply 102, the control circuit 110 and the current sensing circuit 204, and the current sensing circuit 204 is more Coupled to the control circuit 110. The control circuit 110 can control the voltage conversion circuit 202 to convert the voltage provided by the power supply to generate the charging voltage V1, and the current sensing circuit 204 can sense the charging current I1 and transmit the sensing result to the control circuit 110.

In addition, the detection circuit 108 may include a diode D1, a voltage divider circuit 208, a resistor R3, and a comparator A1. In this embodiment, the voltage divider circuit 208 may include resistors R1 and R2, wherein the anode of the diode D1 The output terminal of the reference voltage generating circuit 106 and the first terminal of the resistor R3 are respectively coupled to the cathode, the second terminal of the resistor R3 is coupled to the output terminal of the charging circuit 104, and the resistors R1 and R2 are coupled to the cathode of the diode D1 and Between grounding, the positive and negative input terminals of the comparator A1 are respectively coupled to the common node of the resistors R1 and R2 and the second terminal of the resistor R3, and the output terminal of the comparator A1 is coupled to the control circuit 110.

When the load RL is not connected to the charging device 100 (for example, when the wireless earphone is not placed in the charging box (that is, the charging device 100)), the control circuit 110 is in an ultra-low power state (step S302), and the charging circuit 104 (including voltage The conversion circuit 202 and the current sensing circuit 204) are controlled by the control circuit 110 to enter the power-saving mode, which can reduce the leakage current of the charging device (the leakage current can be, for example, 25μA), and achieve the effect of saving power and ensuring safety . In detail, when the load RL is not connected to the charging device 100, since the charging circuit 104 does not output the charging voltage V1 at this time, the voltage at the negative input terminal of the comparator A1 will be approximately equal to the reference voltage provided by the reference voltage generating circuit 106 (for example, 3V, but not limited to this) The voltage after passing through the resistor R3, and the positive input terminal of the comparator A1 will be equal to the divided voltage generated after the resistors R1 and R2 divide the reference voltage provided by the reference voltage generating circuit 106, That is, the voltage at the negative input terminal of the comparator A1 will be greater than the voltage at the positive input terminal, so the output terminal of the comparator A1 will be at a low voltage level (that is, the detection signal S1 will be at a low voltage level). The control circuit 110 can determine whether the detection signal S1 is converted to a high voltage level (S304). When the detection signal S1 output by the comparator A1 is a low voltage level, the control circuit 110 determines that the load RL is not connected according to the detection signal S1 To the charging device 100.

When the load RL is just connected to the charging device 100, the equivalent resistance of the resistor R3 and the load RL will divide the reference voltage provided by the reference voltage generating circuit 106, so that the voltage at the negative input terminal of the comparator A1 is less than the voltage at the positive input terminal. , So that the detection signal S1 output by the comparator A1 is converted to a high voltage level, and the control circuit 110 can determine that the load RL is connected to the charging device 100 according to the voltage level of the detection signal S1. At this time, the leakage current of the charging device 100 Slightly increased (leakage current can be increased slightly to 40 μA, for example).

When the detection signal S1 output by the comparator A1 turns to a high voltage level, the control circuit 110 is awakened from the ultra-low power state (step S306), and then controls the charging circuit 104 to provide a charging voltage V1 (step S308), where The charging voltage V1 can be, for example, 5V, but it is not limited thereto. During the period when the charging circuit 104 is charging the load RL, since the negative input terminal of the comparator A1 directly receives the charging voltage V1 provided by the charging circuit 104, and the charging voltage V1 will cause the diode D1 to enter the cut-off state, so that the comparator The positive input terminal of A1 receives the voltage obtained by dividing the charging voltage V1 through the resistors R1~R3, so the detection signal S1 output by the comparator A1 will be converted to a low voltage level. The control circuit 110 can determine whether the load RL has been charged according to the voltage level of the detection signal S1 and the charging current I1 (step S310). For example, when the charging current I1 is greater than the preset current value, the control circuit 110 determines that the load RL has not been fully charged, and returns to step S308 to continue to control the charging circuit 104 to provide the charging voltage V1. When the charging current I1 is less than or equal to the preset current value, the control circuit 110 determines that the load RL has been charged, and controls the charging circuit 104 to stop providing the charging voltage V1 (step S312). At this time, the positive and negative input terminals of the comparator A1 The voltage is similar to the situation when the load RL is just connected to the charging device 100, the detection signal output by the comparator A1 will be converted to a high voltage level, and the leakage current is also similar, for example, about 40 μA).

It can be seen from the embodiments in Figures 2 and 3 that the charging device 100 can effectively improve the disadvantages of traditional charging devices such as large size, high cost, easy damage to the mechanical structure, poor waterproof and dustproof effects, and the need to add additional pins, and can also greatly reduce leakage current. And achieve the effect of power saving. For example, in the case where the load RL is an earphone, after the load RL is charged, if the charging circuit 104 continues to provide the output voltage V1 (which is, for example, 5V), the leakage current between the charging device and the load RL can reach about 1132 μA (including voltage The leakage current of the conversion circuit 202 is 7 μA, the leakage current of the current sensing circuit 204 is 25 μA, the leakage current of the current limiter (not shown) of the charging circuit 104 is 100 μA, and the leakage current of the earphone is 1 mA). If the rechargeable battery used as the power source 102 has a capacity of 500 mAh, the above-mentioned leakage current can consume the power of the rechargeable battery at most after 18 days. Since the control circuit 110 of this embodiment can control the charging circuit 104 to stop providing the charging voltage V1 after determining that the load RL has been charged, that is, to close the output loop, the time for the rechargeable battery to be consumed can be extended to a maximum of 520 Day, greatly increase the usable time of rechargeable batteries.

4 is a schematic diagram of a charging device according to another embodiment of the present invention. FIG. 5 is a schematic diagram of a charging process of a charging device according to another embodiment of the present invention. Please refer to FIGS. 4 and 5. In the embodiment of FIG. 4, the detection circuit 108 includes a resistor R4 and a diode D2. The resistor R4 is coupled between the reference voltage generating circuit 106 and the anode of the diode D2, and the cathode of the diode D2 is coupled to the charging circuit. 104's output. Similar to the embodiment in FIG. 3, when the load RL is not connected to the charging device 100, the control circuit 110 is in an ultra-low power state (step S502). At this time, the charging circuit 104 is controlled by the control circuit 110 and enters the power saving mode. The leakage current of the charging device 100 may be about 5 μA. In detail, since the charging circuit 104 has not been connected to the load RL at this time, the detection signal S1 generated on the common contact of the resistor R4 and the diode D2 will be at a high voltage level (the voltage value of the detection signal S1 at this time Approximately equal to the reference voltage provided by the reference voltage generating circuit 106 (for example, 3V) after passing through the resistor R4), the control circuit 110 can determine whether the detection signal S1 is turned to a low voltage level (S504). When the detection signal S1 output by the comparator A1 is at a high voltage level, the control circuit 110 determines that the load RL is not connected to the charging device 100 according to the detection signal S1.

When the load RL is just connected to the charging device 100, the resistor R4 and the resistor R5 of the load RL divide the reference voltage provided by the reference voltage generating circuit 106, so that the detection signal S1 turns to a low voltage level. The control circuit 110 can determine that the load RL is connected to the charging device 100 according to the voltage level of the detection signal S1. At this time, the leakage current of the charging device 100 is slightly increased (the leakage current may be slightly increased to 23 μA, for example).

When the detection signal S1 output by the comparator A1 turns to a low voltage level, the control circuit 110 is awakened from the ultra-low power state (step S506), and then controls the charging circuit 104 to provide a charging voltage V1 (step S508), where The charging voltage V1 can be, for example, 5V, but it is not limited thereto. During the period when the charging circuit 104 is charging the load RL, since the charging voltage V1 will cause the diode D2 to enter the off state, the voltage value of the detection signal S1 will be approximately equal to the reference voltage provided by the reference voltage generating circuit 106 after passing through the resistor R4 That is, the detection signal S1 will be converted to a high voltage level. The control circuit 110 can determine whether the load RL has been charged according to the voltage level of the detection signal S1 and the charging current I1 (step S510). For example, when the charging current I1 is greater than the preset current value, the control circuit 110 determines that the load RL has not been fully charged, and returns to step S508 to continue to control the charging circuit 104 to provide the charging voltage V1. When the charging current I1 is less than or equal to the preset current value, the control circuit 110 determines that the load RL has been charged, and controls the charging circuit 104 to stop providing the charging voltage V1 (step S512). At this time, the leakage current of the charging device 100 is similar to that of the load. When the RL is just connected to the charging device 100, for example, it is about 23 μA.

It can be seen from the embodiments of FIGS. 4 and 5 that fewer components are required to implement the charging device 100 of the embodiments of FIGS. 4 and 5, which can further improve the traditional charging device's large size, high cost, easy damage to the mechanical structure, poor waterproof and dustproof effects, and requirements. The shortcomings of additional pins, and further reduce the leakage current, and achieve better power saving effect. Similar to the embodiment in FIG. 2, when the load RL is an earphone, after the load RL is charged, if the charging circuit 104 continues to provide the output voltage V1, the leakage current of the charging device and the load RL will cause the charging of the power supply 102 The battery's power is quickly consumed. Since the control circuit 110 of the embodiment of the present case can also control the charging circuit 104 to stop providing the charging voltage V1 after determining that the load RL has been charged, that is, to close the output circuit, the time for the rechargeable battery to be consumed can be extended to the maximum In 906 days, the time for the rechargeable battery to be exhausted was greatly lengthened, and the usable time of the rechargeable battery was increased.

To sum up, the detection circuit of the embodiment of the present invention can provide a detection signal according to the divided voltage on the divided voltage path between the output terminal of the charging circuit and the output terminal of the reference voltage generating circuit, and the control circuit according to the detection The signal determines whether the load is connected to the charging device. In this way, there is no need to use magnets, mechanical switches, or additional spring pin pins to detect whether the load is connected to the charging device, and it can effectively improve the large size, high cost, and easy damage of the mechanical structure of the traditional charging device. Shortcomings such as poor waterproof and dustproof effects and the need for additional pins. In some embodiments, it is also possible to reduce the leakage current by controlling the charging circuit to stop supplying the charging voltage, so as to achieve the effect of saving power and extending the use time.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the relevant technical field can make some changes and modifications without departing from the spirit and scope of the present invention. The protection scope of the present invention shall be subject to those defined by the attached patent application scope.

100: charging device 102: Power 104: charging circuit 106: Reference voltage generating circuit 108: Detection circuit 110: control circuit 202: voltage conversion circuit 204: Current Sensing Circuit 208: Voltage divider circuit V1: Charging voltage S1: Detection signal RL: load I1: Charging current D1, D2: Diode R1~R4: resistance A1: Comparator S302~S312, S502~S512: charging process steps

Fig. 1 is a schematic diagram of a charging device according to an embodiment of the present invention. Fig. 2 is a schematic diagram of a charging device according to another embodiment of the present invention. FIG. 3 is a schematic diagram of a charging process of a charging device according to an embodiment of the present invention. Fig. 4 is a schematic diagram of a charging device according to another embodiment of the present invention. FIG. 5 is a schematic diagram of a charging process of a charging device according to another embodiment of the present invention.

100: charging device

102: Power

104: charging circuit

106: Reference voltage generating circuit

108: Detection circuit

110: control circuit

V1: Charging voltage

S1: Detection signal

RL: load

I1: Charging current

Claims (10)

A charging device includes: a power source; a charging circuit coupled to the power source and providing a charging voltage according to the power source; a reference voltage generating circuit coupled to the power source and providing a reference voltage according to the power source; and a detection circuit, The output terminal of the charging circuit is directly connected with the output terminal of the reference voltage generating circuit, the detection circuit includes a voltage dividing path directly connected between the output terminal of the charging circuit and the output terminal of the reference voltage generating circuit, the The detecting circuit provides a detecting signal according to the divided voltage on the voltage dividing path; and a control circuit, directly connected to the reference voltage generating circuit and the output terminal of the detecting circuit, for receiving the detecting signal, and according to The detection signal determines whether a load is connected to the charging device to switch the state of the control circuit. The charging device described in item 1 of the scope of patent application, wherein the control circuit also judges the charging state of the load according to the charging current of the charging circuit. The charging device according to claim 1, wherein the detection circuit includes: a diode, the anode of which is coupled to the output terminal of the reference voltage generating circuit; a resistor, which is coupled to the cathode of the diode And the output terminal of the charging circuit; a voltage divider circuit, coupled to the common junction of the diode and the resistor, divides the voltage on the common junction of the diode and the resistor to generate the division Voltage; and a comparator whose positive and negative input terminals are respectively coupled to the voltage divider circuit and the charging circuit The output terminal of the circuit compares the divided voltage with the charging voltage to generate the detection signal. The charging device according to item 3 of the scope of patent application, wherein the voltage divider circuit includes: a first resistor; and a second resistor, which is connected in series with the first resistor to the common connection of the diode and the resistor Between the point and the ground, the common connection point of the first resistor and the second resistor is coupled to the positive input terminal of the comparator. The charging device according to claim 1, wherein the detection circuit includes: a first resistor, the first end of which is coupled to the reference voltage generating circuit; and a diode, the anode and the cathode of which are respectively coupled The second end of the first resistor and the output end of the charging circuit, the load has a second resistor, the common contact of the first resistor and the diode generates the detection signal, wherein when the load is connected to the When charging the device, the second resistor is coupled between the cathode of the diode and the ground. For the charging device described in item 1 of the scope of patent application, when the control circuit determines that the load is not connected to the charging device according to the detection signal, the control circuit controls the charging circuit to stop outputting the charging voltage. The charging device described in item 2 of the scope of patent application, wherein when the control circuit determines that the load is connected to the charging device according to the detection signal and the charging current and that the load has not been fully charged, the control circuit controls the charging The circuit outputs the charging voltage to charge the load. As the charging device described in item 2 of the scope of patent application, when the control When the control circuit determines that the load is connected to the charging device according to the detection signal and the charging current and the load has completed charging, the control circuit controls the charging circuit to stop outputting the charging voltage. The charging device according to claim 1, wherein the charging circuit includes: a voltage conversion circuit coupled to the control circuit and converting the voltage provided by the power supply to generate the charging voltage; and a current sensing circuit coupled The voltage conversion circuit and the control circuit are connected, the charging current is sensed, and the sensing result is transmitted to the control circuit. The charging device described in item 1 of the scope of patent application, wherein the charging voltage is greater than the reference voltage.

Images