CN217741957U

CN217741957U - Switching device and lighting system

Info

Publication number: CN217741957U
Application number: CN202221237796.9U
Authority: CN
Inventors: 李志峰; 杨磊
Original assignee: Schneider Electric Industries SAS
Current assignee: Schneider Electric Industries SAS
Priority date: 2022-05-20
Filing date: 2022-05-20
Publication date: 2022-11-04
Anticipated expiration: 2032-05-20

Abstract

Embodiments of the present disclosure provide a switching device and a lighting system. The switching device includes: a switch adapted to make or break a connection of a load to a line; a control unit configured to control an operation of the switch; a rechargeable battery configured to supply power to the control unit when the switch is turned off; and a power take-off unit adapted to draw power from the line and configured to be able to charge the rechargeable battery; wherein the control unit is configured to: the charging current for charging the rechargeable battery is changed based on the output voltage of the power take-out unit. Therefore, when loads with different powers are connected, the magnitude of the charging current can be adjusted to be matched with the power of the connected load, and therefore the compatibility of the switch device is improved.

Description

Switching device and lighting system

Technical Field

Embodiments of the present disclosure relate to switching devices, and more particularly, to switching devices using rechargeable batteries.

Background

Loads are often used with switches that can make or break the connection of the load to a power source. A control unit is typically used to control the operation of the switches. With the switch open, the control unit still needs to draw power from the power supply to maintain operation of the control unit itself. However, leakage current due to the control unit drawing power may flow through the load with the switch open, which is undesirable.

In the case where the load is a lamp, most of the current single fire switches on the market have a "ghost fire" problem. This is because the energy (or current) of the control unit for the switch is also derived from the mains supply when the lamp is off, and this current will flow through the lamp. Especially, in the case of a very low power LED lamp, such as a 3W bulb, the current will continuously charge the electrolytic capacitor used in the bulb, and when the voltage on the electrolytic capacitor reaches a certain level, the LED lamp will emit light. After the LED lamp bead emits light, the energy on the electrolytic capacitor is rapidly reduced because of consumption, and the lamp is turned off. When the lamp goes out, the voltage on the electrolytic capacitor can be increased again, so that the LED lamp beads can flicker intermittently, and an undesirable 'ghost fire' problem is caused.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is an object of the disclosed embodiments to provide a switching device and a lighting system including the same, which can solve or alleviate at least one of the problems of the related art.

In a first aspect of the present disclosure, a switching device is provided. The switching device includes: a switch adapted to make or break a connection of a load to a line; a control unit configured to control an operation of the switch; a rechargeable battery configured to supply power to the control unit when the switch is turned off; and a power take-off unit adapted to draw power from the line and configured to be able to charge the rechargeable battery; wherein the control unit is configured to: the charging current for charging the rechargeable battery is changed based on the output voltage of the power take-out unit.

In such an embodiment, when the switch is open, the control unit is powered by the rechargeable battery, and no longer needs to draw energy from the mains. Therefore, when the switch is turned off, a leakage current flowing through the load does not occur. In the case where the load is a lamp, there is no "ghost fire" problem. In addition, the rechargeable battery can prolong the service life of the product and improve the user experience.

When loads with different powers are connected, the allowed power taking capability is different because the load currents are different. If the charging current of the rechargeable battery is too large to exceed the allowable power taking capability, the output voltage of the power taking unit will decrease, thereby causing the power taking unit to work abnormally (e.g., the power taking is unsuccessful). When loads with different powers are connected, the embodiment of the disclosure can adjust the magnitude of the charging current based on the output voltage of the power taking unit, so that the adjusted charging current is matched with the allowed power taking capability, and the normal work of the switch device is ensured. Therefore, the compatibility of the switching device can be improved.

In some embodiments, the control unit is configured to: outputting a Pulse Width Modulation (PWM) signal to a charging unit for a rechargeable battery for controlling a charging current; and changing the duty ratio of the PWM signal based on the output voltage of the power taking unit. By adjusting the duty cycle of the PWM signal, the average value of the charging current can be controlled. This provides a feasible way of controlling the charging current.

In some embodiments, the charging unit is a linear constant current charging unit. The charging current of the linear charging scheme is less than the charging current of the non-linear charging scheme. Thus, the charging current of the linear charging scheme is more easily matched to the load current of the low power load, and the power consumption is lower.

In some embodiments, the power take-off unit is further configured to: when the switch is turned on, power is supplied to the control unit and the rechargeable battery is charged. In such an embodiment, the control unit may be powered with the take-out voltage while the rechargeable battery is being charged with the take-out voltage. Therefore, the control unit may not consume the capacity of the battery when the switch is turned on, thereby extending the life span of the product.

In some embodiments, the switching device further comprises a power conversion unit connected between the power taking unit and the control unit, the power conversion unit being configured to convert an output voltage of the power taking unit into a supply voltage for the control unit.

In some embodiments, the switching device further includes a voltage sampling unit connected between the power taking unit and the control unit, the voltage sampling unit being configured to sense a value of an output voltage of the power taking unit and provide the sensed value to the control unit. The voltage sampling unit may lower or raise the output voltage of the power taking unit to a value suitable for sampling by the control unit.

In some embodiments, the voltage sampling unit comprises a resistive voltage divider. The resistive voltage divider may reduce the output voltage of the power taking unit to a value suitable for sampling by the control unit.

In some embodiments, the switch comprises a relay or thyristor.

In some embodiments, the switch comprises a latching relay and the load comprises an LED light. The self-locking relay can automatically keep continuously electrified after being switched on. The LED lamp has the advantages of energy conservation, environmental protection, long service life and the like, and is gradually replacing the traditional lamp.

In some embodiments, the control unit comprises a wireless communication device. In this way, the control unit can communicate wirelessly with another device (e.g., a cell phone or a computer, etc.), so that an intelligent switch can be provided.

In some embodiments, the switchgear comprises a single fire switch. In such an embodiment, the neutral wire is connected directly to the load without passing through the switch. Therefore, only one input line, namely the input live wire, is arranged on the switch device. Most of the existing houses and office buildings are only provided with a single live wire, so that the single live wire switch is widely applied.

In a second aspect of the present disclosure, a lighting system is provided. The lighting system includes: an LED lamp; and a switching device according to the first aspect of the present disclosure. The lighting system has all the advantages of the switching device and will not be described in further detail herein.

Drawings

A switching device and a lighting system including the switching device according to embodiments of the present disclosure are described below with reference to the accompanying drawings, in which:

fig. 1 shows a schematic diagram of a switching device and a lighting system comprising the switching device according to one embodiment of the present disclosure;

fig. 2 illustrates a circuit diagram of a charging unit and a voltage sampling unit according to one embodiment of the present disclosure.

Detailed Description

Embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that in the drawings, similar components or functional elements may be denoted by the same reference numerals. The accompanying drawings are intended to be merely illustrative of embodiments of the disclosure and not limiting thereof. Persons skilled in the art may derive alternatives from the following description without departing from the spirit and scope of the disclosure.

As mentioned above, most of the current single fire switches on the market suffer from the "ghost fire" problem. To eliminate the "ghost fire" problem or other leakage problem to the load, batteries (e.g., dry cell or non-rechargeable batteries) may be used to power the control circuitry in the switching device. In this way, the control part in the switching device does not need to draw energy from the mains supply, and no current flows into the external lamp load when the switch is switched off, so that there is no ghost fire problem. However, since the space of the switching device (particularly, the smart switch) is limited, the use capacity of the battery is limited, so that the capacity of the battery is quickly exhausted. Furthermore, in this solution, the control part of the switching device is powered by the battery, whether the switch is on or off, which also causes a rapid depletion of the battery. This can seriously affect the useful life of the product.

A mode of combining a rechargeable battery and a dry battery can be used, and the mode can also solve the problem of the ghost fire of taking electricity by single fire. Due to the addition of the rechargeable battery, the service life of the product can be prolonged, and the user experience is improved. Since the rechargeable battery needs to be charged by taking electricity when the external load lamp is turned on, the rechargeable battery generally adopts a constant-current constant-voltage charging mode. However, if the power of the connected load (e.g., LED light bulb) is low (e.g., 3W or less), the load current flowing through the load is low, which results in a limited current that can be shunted from the load current by a single hot-strike. At this time, if the required charging current is too large, the power-taking circuit may work abnormally, and the rechargeable battery may not be charged normally. On the other hand, if the rechargeable battery is charged with too small charging current, the charging time will be too long.

The switching device provided by the present disclosure may change a charging current for charging a rechargeable battery based on an output voltage of a power taking unit. When the loads with different powers are connected, the size of the charging current can be adjusted, so that the switching device can work normally, the situation that electricity is not taken successfully due to overlarge charging current and the control unit does not work is avoided. This improves the compatibility of the switching device. Moreover, the charging current is not too small, thereby shortening the charging time.

A switching device and a lighting system including the same of the embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. In the drawings, a double-headed arrow represents an alternating current signal, and a single-headed arrow represents a direct current signal. Fig. 1 shows a schematic diagram of a switching device 120 and a lighting system 100 comprising the switching device 120 according to one embodiment of the present disclosure. As shown in fig. 1, the lighting system 100 may include a load 110 and a switching device 120. The load 110 may be connected to the live line L via a switching device 120.

The load 110 may be an LED lamp. The LED lamp has the advantages of energy conservation, environmental protection, long service life and the like, and is gradually replacing the traditional lamp. Although LED lamps are exemplified as the load 110 in some embodiments, the present disclosure may also be applicable to other types of loads used with switching devices. Also, the lamp applicable to the present disclosure is not limited to the LED lamp, and the present disclosure may also be applicable to other types of lamps, such as a conventional tungsten lamp, an energy saving lamp, an incandescent lamp, or a fluorescent lamp, etc.

As shown in fig. 1, the switching device 120 may include a switch 130, a control unit 140, a rechargeable battery 160, and a power-taking unit 150. The switch 130 may switch the load 110 on or off from the line L. The switch 130 shown in fig. 1 has one output connected to the first live line L1. It is also possible that the switch 130 has a plurality of outputs to be connected to the plurality of loads 110 through a plurality of live lines (a first live line L1, a second live line L2, a third live line L3, etc.), respectively. Although not shown, the switch 130 may also include a drive circuit associated with the switch. The control unit 140 may control the operation of the switch 130. The control unit 140 may send a control signal to the switch 130 to turn the switch 130 on or off.

When the switch 130 is turned off, the rechargeable battery 160 can supply power to the control unit 140 to ensure the control unit 140 operates normally. To this end, the switching device 120 may include a power supply unit 164 that supplies the output power of the rechargeable battery 160 to the control unit 140. Since the control unit 140 no longer needs to draw energy from the mains with the switch 130 open, no leakage current through the load 110 will occur. In the case where the load 110 is a lamp, there is no "ghost fire" problem. In addition, the rechargeable battery is not only dependent on a dry battery, so that the service life of the product can be prolonged, and the user experience is improved.

The power taking unit 150 may draw power from the line L and charge the rechargeable battery 160 with the drawn power. In the embodiment of the present disclosure, the control unit 140 may change the charging current for charging the rechargeable battery 160 based on the output voltage of the power taking unit 150. The control unit 140 may constantly recognize the power-taking voltage output by the power-taking unit 150 (also referred to as "output voltage of the power-taking unit 150"), which may be used as an input voltage for the charging unit 162 of the rechargeable battery 160. When the output voltage reaches a different value, the control unit 140 may change the charging current for the rechargeable battery 160. When loads 110 (such as light bulbs) with different powers are connected, the allowed power taking capability is different because the load current flowing through the loads 110 is different. If the charging current of the rechargeable battery 160 is too large to exceed the allowable power-taking capability, the output voltage of the power-taking unit 150 will decrease, and the power-taking unit 150 will operate abnormally and cannot charge the rechargeable battery 160 normally. The embodiment of the present disclosure may adjust the magnitude of the charging current based on the output voltage of the power taking unit 150, so that the adjusted charging current matches the allowed power taking capability, that is, matches the power of the connected load. In this way, when the loads 110 with different powers are connected, the normal operation of the switching device 120 can be ensured, and the power getting failure caused by the overlarge charging current can be avoided. Accordingly, the compatibility of the switching device 120 with different loads 110 may be improved. In short, the charging current may be adjusted to a suitable level based on the output voltage of the power taking unit 150. The adjusted charging current is not too large to cause abnormal operation of the power taking unit 150, but not too small to cause overlong charging time.

As shown in fig. 1, the switching device 120 may include a charging unit 162 for charging the rechargeable battery 160. The charging unit 162 may charge the rechargeable battery 160 using the output voltage of the power taking unit 150. In some embodiments, the control unit 140 may output a Pulse Width Modulation (PWM) signal to the charging unit 162 for controlling the charging current. The control unit 140 may include a PWM signal generator for generating a PWM signal. The frequency of the PWM signal may be between 10Hz and 1 KHz. The control unit 140 may change the duty ratio of the PWM signal based on the output voltage of the power taking unit 150. When the output voltage of the power taking unit 150 reaches different values, the control unit 140 may output the PWM signal to the charging unit 162 and change the duty ratio of the PWM signal. By adjusting the duty cycle of the PWM signal, the average value of the charging current can be controlled. This provides a feasible way of controlling the charging current of the rechargeable battery 160. In such an embodiment, the control unit 140 may continuously identify the output voltage of the power taking unit 150 and determine the duty ratio of the corresponding PWM signal to control the charging current and improve the compatibility of the switching device 120.

The control unit 140 may also be referred to herein as a control portion, a control module, a controller, or a control circuit. By way of example only, and not limitation, the control unit 140 may include a Micro Control Unit (MCU).

In some embodiments, the control unit 140 may include a wireless communication device. The control unit 140 may implement transceiving of wireless data. In this case, the control unit 140 may be referred to as a wireless control unit. For example, the control unit 140 may include Zigbee or Bluetooth Low Energy (BLE) module circuits. The control unit 140 may also include radio frequency circuitry for transceiving wireless data. In this way, the control unit 140 may wirelessly communicate with another device (e.g., a cell phone or a computer, etc.) to facilitate remote control of the load 110 by a user. Such an embodiment facilitates providing an intelligent switch.

As shown in fig. 1, the load 110, the switch 130, and the power taking unit 150 are connected in series between the neutral line N and the live line L. Although fig. 1 shows the switch 130 located between the load 110 and the power-taking unit 150, it is also possible that the power-taking unit 150 is located between the load 110 and the switch 130.

When the switch 130 is in the off state, the lamp (i.e., the load 110) is off, the power taking unit 150 does not operate, and the rechargeable battery 160 supplies power to the control unit 140 through the power supply unit 164. Alternatively, the switching device 120 may include a non-rechargeable battery (e.g., a dry cell battery) to provide the power required by the components of the switching device 120 when the capacity of the rechargeable battery 160 is exhausted.

When the switch 130 is in the on state, the lamp is on, and the power-taking unit 150 is connected in series with the load 110, and the load current flowing through the load 110 also flows through the power-taking unit 150. The power-taking unit 150 may draw power from the load current to power the control unit 140 and charge the rechargeable battery 160. That is, the power supply unit 150 operates when the lamp is turned on. The power taking unit 150 may have an input terminal connected to the live line L, and have a first output terminal and a second output terminal. The first output is connected to a switch 130 to deliver an alternating current signal. The second output may be connected to both the control unit 140 and the rechargeable battery 160 to deliver a direct current signal. In such an embodiment, the control unit 140 may be powered with the power-taking voltage while the rechargeable battery 160 is being charged with the power-taking voltage. Accordingly, when the switch 130 is turned on, the control unit 140 may not consume the capacity of the battery, thereby extending the life span of the product.

The control unit 140 may detect an output voltage of the power taking unit 150. When the output voltage of the power-taking unit 150 is higher than the threshold value enough to supply power to the control unit 140, the control unit 140 may send a disable signal to the power supply unit 164 to stop the supply of power to the control unit 140 by the rechargeable battery 160. When the output voltage of the power-taking unit 150 is lower than the threshold value and is insufficient to supply power to the control unit 140, the control unit 140 may transmit an enable signal to the power supply unit 164 to supply power to the control unit 140 using the rechargeable battery 160.

The control unit 140 may compare the output voltage Va of the power taking unit 150 with a threshold value and increase or decrease the charging current based on the comparison result. When the switch 130 is turned off, the control unit 140 may set the duty ratio of the PWM signal to 0. That is, the rechargeable battery 160 is not charged. After the switch 130 is turned on, when the control unit 140 detects that the output voltage Va of the power-on unit 150 is greater than the first threshold Vth1 (e.g., 6V), the control unit 140 may change from outputting a PWM signal having a duty ratio of 0 to outputting a PWM signal having a certain duty ratio (e.g., 30%). The control unit 140 constantly detects the output voltage Va of the power-taking unit 150. After a while, when the output voltage Va of the power taking unit 150 is greater than the second threshold Vth2 (e.g., 5V), the control unit 140 may increase the duty ratio of the PWM signal, for example, to 40%. If Va is less than Vth2, the duty cycle is reduced to 20%. In this way, the control unit 140 increases or decreases the duty ratio of the PWM signal by continuously detecting the output voltage Va of the power taking unit 150, so that the charging current of the rechargeable battery 160 matches the load current. It is noted that the numerical values mentioned herein are only illustrative and not restrictive.

In some embodiments, the power-taking unit 150 supplies power to the control unit 140 through the power conversion unit 180. The power conversion unit 180 may convert the output voltage of the power taking unit 150 into a suitable supply voltage for the control unit 140. For example, the power conversion unit 180 may provide a stable 3.3V voltage required by the control unit 140 regardless of the power-taking voltage. To some extent, the power conversion unit 180 may have a voltage stabilizing function.

In some embodiments, the control unit 140 detects the output voltage of the power taking unit 150 through the voltage sampling unit 170. The voltage sampling unit 170 may sense a value of the output voltage of the power taking unit 150 and provide the sensed value to the control unit 140. The voltage sampling unit 170 may lower or raise the output voltage of the power taking unit 150 to a value suitable for sampling by the control unit 140.

In some embodiments, the switch 130 may include a relay or thyristor. More specifically, the switch 130 may include a self-locking relay. The self-locking relay can automatically keep continuously electrified after being switched on.

By way of example only, and not limitation, the switching device 120 may be a smart switch or a wall switch. The switching device 120 may include a single fire switch in which the load 110 is connected directly to the neutral line N, rather than through the switch 130. There is only one input line, i.e., input line hot, on the switching device 120. Most of the existing houses and office buildings are only provided with a single live wire, so that the single live wire switch is widely applied.

Fig. 2 illustrates a circuit diagram of the charging unit 162 and the voltage sampling unit 170 according to one embodiment of the present disclosure. As shown in fig. 2, the voltage sampling unit 170 may include a resistive voltage divider. By way of example only, and not limitation, the resistive voltage divider includes a resistor R1 and a resistor R2. The resistor R1 and the resistor R2 are connected in series between the output voltage of the power taking unit 150 and the ground. The output signal of the resistive voltage divider at the node between the resistor R1 and the resistor R2 is provided to the control unit 140 for ADC (analog-to-digital conversion) sampling to determine the value of the output voltage of the power taking unit 150. The resistive voltage divider may reduce the output voltage of the power taking unit 150 to a value suitable for sampling by the control unit 140. Other types of voltage dividers are also possible.

As shown in fig. 2, the charging unit 162 may include a charging chip 210, a driving circuit 220, and an external resistor Rg. The output voltage of the power-taking unit 150 is connected to the pin VIN of the charging chip 210. The charging unit 162 shown in fig. 2 is a linear constant current charging unit. The charging current of the linear charging scheme (e.g., a few mA) is smaller than the charging current of the non-linear charging scheme (e.g., a few hundred mA). Thus, the charging current of the linear charging scheme is more easily matched to the load current of the low power load. That is, the linear charging scheme is more suitable for small power loads and the power consumption is lower. The external resistor Rg and the driving circuit 220 connected through the PROG pin of the charging chip 210 can control the magnitude of the charging current. The BAT pin is a voltage output pin connected to the rechargeable battery 160. The output of the BAT pin may have overvoltage protection. The CHRG pin is a charge state indication and the STDBY pin is a full charge state indication. The CHRG pin and the STDBY pin may be connected to the control unit 140 for further control.

In the linear constant current charging scheme shown in fig. 2, icharge = Vref/Rg, where Icharge is the charging current, vref is a constant level reference signal inside the charging chip 210, and Rg is an external resistor.

The driver circuit 220 connected to the external resistor Rg may comprise a switch, which may be, for example, a field effect transistor, a triode, or other similar controllable switching transistor. The PWM signal from the control unit 140 can adjust the on and off of the switching tube. When the PWM signal is high, the charging current is Icharge. When the PWM signal is low, the charging current Icharge is 0. Therefore, if the duty ratio of the PWM signal is n, the charging current Icharge is Icharge = Vref × n/Rg.

In such an embodiment, the control unit 140 obtains the value of the output voltage of the power taking unit 150 by sampling the output of the resistive voltage divider. Based on this value, the control unit 140 may adjust the duty ratio of the PWM signal, and may control the charging current average value of the rechargeable battery 160.

Through the above description, the present disclosure proposes a new control method for battery charging of a switching device, which may improve product compatibility. The switchgear of the present disclosure is particularly suitable for single fire switches and can solve the "ghost fire" problem.

A "unit" or "module" described herein may be implemented by a circuit, an integrated circuit, a chip, or other hardware. Also, one unit or module may be implemented by one or more hardware items, and a plurality of units or modules may be implemented by the same hardware item.

Those skilled in the art will understand that: the foregoing description is provided for the purpose of illustration and not limitation. It will be apparent to one skilled in the art that the present disclosure may be practiced in other implementations that depart from these specific details. Moreover, unnecessary detail of known functions and structures may be omitted from the current description so as not to obscure the present disclosure.

Although specific embodiments have been illustrated and described herein, those of ordinary skill in the art appreciate that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiments shown and that the disclosure has other applications in other environments. This application is intended to cover any adaptations or variations of the present disclosure. The following claims should in no way be construed to limit the scope of the disclosure to the specific embodiments described herein.

Claims

1. A switchgear, comprising:

a switch (130) adapted to switch the load (110) on or off from the live line (L);

a control unit (140) configured to control operation of the switch (130);

a rechargeable battery (160) configured to supply power to the control unit (140) when the switch (130) is open; and

a power take-off unit (150) adapted to draw power from the line of fire (L) and configured to be able to charge the rechargeable battery (160);

wherein the control unit (140) is configured to: changing a charging current for charging the rechargeable battery (160) based on an output voltage of the power taking unit (150).

2. The switching device according to claim 1, wherein the control unit (140) is configured to:

outputting a pulse width modulated, PWM, signal to a charging unit (162) for the rechargeable battery (160) for controlling the charging current; and

changing a duty ratio of the PWM signal based on the output voltage of the power taking unit (150).

3. A switching device according to claim 2, characterized in that the charging unit (162) is a linear constant current charging unit.

4. The switchgear device according to claim 1, wherein said electricity taking unit (150) is further configured to: when the switch (130) is turned on, the control unit (140) is powered and the rechargeable battery (160) is charged.

5. The switching device according to claim 4, characterized in that the switching device (120) further comprises a power conversion unit (180) connected between the power taking unit (150) and the control unit (140), the power conversion unit (180) being configured to convert the output voltage of the power taking unit (150) into a supply voltage for the control unit (140).

6. The switching device according to claim 1, wherein the switching device (120) further comprises a voltage sampling unit (170) connected between the power taking unit (150) and the control unit (140), the voltage sampling unit (170) being configured to sense a value of the output voltage of the power taking unit (150) and to provide the sensed value to the control unit (140).

7. The switching device according to claim 6, wherein the voltage sampling unit (170) comprises a resistive voltage divider.

8. A switching device according to any of claims 1-7, characterized in that the switch (130) comprises a relay or thyristor.

9. A switching device according to any of claims 1-7, characterized in that the switch (130) comprises a self-locking relay and the load (110) comprises an LED lamp.

10. A switching device according to any of claims 1-7, characterized in that the control unit (140) comprises wireless communication means.

11. A switchgear device according to any of the claims 1-7, characterized in that the switchgear device comprises a single live switch.

12. An illumination system, comprising:

an LED lamp; and

a switching device according to any one of claims 1-11.