Description
POWER SUPPLY FOR DIGITAL-DOORLOCK USING WIRELESS POWER TRANSMISSION
Technical Field
[1] The present invention relates to a power supply for a digital doorlock, and more particularly to a power supply capable of supplying driving power to a digital doorlock without use of a battery or a power cable. Background Art
[2] A digital doorlock is operated by electric energy to selectively lock a door, and recently various identifying means using password, fingerprint recognition, card reader and the like is added thereto to give excellent door control functions.
[3] However, a conventional digital doorlock is supplied with power through a battery or a power cable, which is not useful for construction and requires much cost in maintenance and repair. That is, in case of a digital doorlock using a battery, the battery should be frequently exchanged, which is so cumbersome and takes much costs, and in view of power capacity it is not suitable for various home network and bi¬ directional communication. In addition, in case of a digital doorlock supplied with power through a cable, a data communication cable should be wired to the doorlock via inside of the door together with wires, so it may not be easily constructed and the wires and cables are apt to be easily damaged due to frequently opening/closing behaviors of the door. Disclosure of Invention Technical Problem
[4] The present invention is designed to solve such problems of the prior art, and therefore an object of the invention is to provide a power supply for a digital doorlock, which is capable of supplying power to the digital doorlock without use of battery or power cable.
[5] Another object of the present invention is to provide a power supply for a digital doorlock, which gives sufficient power capacity and data transmitting/receiving functions so that the digital doorlock may bi-directionally exchange data with a home network.
Technical Solution
[6] In order to accomplish the above object, the present invention provides a power supply for a digital doorlock installed to one side of a door, which includes a receiving module connected to a power input terminal of the digital doorlock, the receiving module converting RF (Radio Frequency) power into DC (Direct Current) power and
outputting the DC power to the digital doorlock; and a transmitting module installed out of the door to apply RF power to the receiving module.
[7] The power supply of the present invention may further include a data transmitting/ receiving unit for bi-directionally transmitting and receiving data for operation control of the digital doorlock with the use of a carrier wave corresponding to the RF power as a medium.
[8] The data transmitting/receiving unit preferably conducts the data communication in an ASK (Amplitude Shift Keying) modulation manner.
[9] The power supply of the present invention may further include an interface for supporting the bi-directional communication between the transmitting module and a home network.
[10] The transmitting module is preferably installed to one side of a doorframe cor¬ responding to the door.
Brief Description of the Drawings
[11] These and other features, aspects, and advantages of preferred embodiments of the present invention will be more fully described in the following detailed description, taken accompanying drawings. In the drawings: [12] Fig. 1 is a block diagram showing functional configuration of a power supply for a digital doorlock according to a preferred embodiment of the present invention; [13] Fig. 2 is a circuit diagram partially showing a specific configuration for realizing wireless power transmission and bi-directional data communication; [14] Fig. 3 shows a waveform of a signal related to doorlock operation control, which is received and transmitted by ASK (Amplitude Shift Keying) modulation; and [15] Fig. 4 is a perspective view showing a power supply for a digital doorlock according to a preferred embodiment of the present invention.
Best Mode for Carrying Out the Invention [16] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. [17] Fig. 1 is a block diagram showing functional configuration of a power supply for a digital doorlock according to a preferred embodiment of the present invention. [18] Referring to Fig. 1, the power supply according to the preferred embodiment of the present invention includes a receiving module 10 for converting RF power into DC power and then applying it to a digital doorlock 1, and a transmitting module 20 installed out of a door to supply RF power to the receiving module 10. [19] The receiving module 10 is installed to the door so that its DC output terminal is in connection with a power input terminal (not shown) of the digital doorlock 1. The receiving module 10 includes a receiving antenna 11 for generating an induced elec-
tromotive force corresponding to the RF power applied via a free space, a rectifier 12 for converting AC current output from the receiving antenna 11 into DC current, and a charging/discharging unit 13 connected to an output terminal of the rectifier 12 for charging and discharging. Here, the receiving antenna 11, the rectifier 12 and the charging/discharging unit 13 may be configured with components used in common RFID (Radio Frequency Identification) or WPT (Wireless Power Transmission) techniques. For example, the receiving antenna 11 may adopt a coil antenna, a microstrip patch antenna and so on, and the rectifier 12 may use a rectifying circuit adopting a short-key diode or the like, which has relatively faster switching speed.
[20] DC power generated at the output terminal of the receiving module 10 is transferred to an power input terminal of the digital doorlock 1. Here, the digital doorlock 1 may be selected from various electronic doorlocks that are operated by electric energy and selectively conduct locking operation to the door.
[21] The transmitting module 20 is installed out of the door so that it may be separated from the receiving module 10, and it applies RF power of an electromagnetic waveform to the receiving module 10. Preferably, the transmitting module 20 is installed to a doorframe 101 (see Fig. 4) of the door to face with the receiving module 10, and a distance between the transmitting module 20 and the receiving module 10 is set to be several centimeters.
[22] Additionally, the transmitting module 20 may be configured to selectively shift its operating power into an OFF state when the door is sensed to be open, and to shift into an ON state again when the door is sensed to be closed. Here, a sensor for sensing an open or close state of the door may use a common open/close sensing means such as a magnetic sensor.
[23] For generating RF power, the transmitting module 20 includes a power unit 23 for converting home AC power of about 110-240 V into DC power of about 6 V, an os¬ cillating unit 22 for oscillating the DC power output from the power unit 23 to generate high frequency power of for example 125 kHz, and a transmitting antenna 21 connected to the oscillating unit 22 to transmit RF power to the receiving antenna 11 via a free space. The power unit 23 preferably adopts common SMPS (Switching Mode Power Supply), and the transmitting antenna 21 and the oscillating unit 22 may be configured with components used in common RFTD or WPT techniques.
[24] Preferably, the power supply of the present invention may further include a first data transmitting/receiving unit 14 and a second data transmitting/receiving unit 24 for data communication between the receiving module 10 and the transmitting module 20. Here, the second data transmitting/receiving unit 24 preferably wireless-transmits data related to doorlock operation control, transmitted through a local network such as LAN (Local Area Network), a leased line system and a power line communication system,
to the receiving module 10 through the transmitting antenna 21 by using a carrier wave corresponding to the RF power as a medium. In addition, the first data transmitting/ receiving unit 14 detects and transmits data related to doorlock operation control received in the receiving antenna 11 toward the digital doorlock 1, and also wireless- transmits data informing of recognition and operation status of the digital doorlock 1 to the second data transmitting/receiving unit 24 of the transmitting module 20 through the receiving antenna 11. In this case, the transmitting module 20 is further provided with an interface 25 corresponding to a home network 30 so as to support bi¬ directional communication between the transmitting module 20 and the home network 30.
[25] Fig. 2 partially shows a circuit of the receiving module 10 and the transmitting module 20 for wireless power transmission and bi-direction communication, as an example. Referring to Fig. 2, the receiving module 10 and the transmitting module 20 are respectively provided with a resonance coil Ll and L2 so that RF power is wireless-transmitted from the transmitting module 20 to the receiving module 10 by means of electromagnetic induction. In addition, a transmitting data applied to a TX terminal 26 of the transmitting module 20 via the home network 30 is input to a base terminal of TR2 and TR3 that configure a Push-Pull power amplifier, and then de¬ modulated so that the transmitting data may be transmitted from the resonance coil L2 to the resonance coil Ll. In addition, the data generated at the digital doorlock 1 is input and modulated in a base terminal of TRl through the TX terminal 15 of the receiving module 10 so that it may be transmitted from the resonance coil Ll to the resonance coil L2.
[26] In the bi-directional communication between the transmitting module 20 and the receiving module 10 conducted by the first and second data transmitting/receiving units 14, 24, the modulation of data is preferably conducted according to ASK (Amplitude Shift Keying), which changes the amplitude of the carrier wave in accordance with an input signal, in terms of constructing easiness and price. However, the present invention is not limited to that case, and various modulation manners may be used, (a) of Fig. 3 schematically shows an example of a signal waveform including the data related to doorlock operation control, transmitted from the transmitting module 20 to the receiving module 10 by means of 100% ASK modulation, and (b) of Fig. 3 schematically shows an example of a signal waveform including the data of the digital doorlock, transmitted from the receiving module 10 to the transmitting module 20 by means of about 10% ASK modulation through backscattering of the receiving module 10.
[27] Now, operation of the power supply for a digital doorlock according to the preferred embodiment of the present invention is described.
[28] As shown in Fig. 4, the power supply of the present invention includes a receiving module 10 connected to a digital doorlock 1 installed to a door 100, and a transmitting module 20 installed to a doorframe 101 with being spaced apart from the receiving module 10 by about 2-3 cm. Here, a home AC line of about 220V is wired in the transmitting module 20, and a home network 30 is connected thereto for remote control of the digital doorlock 1 by using the interface 25 as a connection means.
[29] AC power supplied to the transmitting module 20 is converted into DC power of about 6V with passing through the power unit 23 preferably corresponding to SMPS, and the oscillating unit 22 RF-oscillates the DC power into a frequency of for example 125 kHz and then applies it to the transmitting antenna 21 so that the RF power is wireless-transmitted to the receiving module 10 via a free space. Subsequently, induced electromotive force corresponding to the RF power is generated in the receiving antenna 11 of the receiving module 10, and this AC electromotive force is converted into DC by the rectifier 12 and then applied to a power input terminal of the digital doorlock 1 through the charging/discharging unit 13.
[30] Meanwhile, the data for operation control of the doorlock, input to the transmitting module 20 through the home network 30, is preferably ASK-modulated by the second data transmitting/receiving unit 24 and then wireless-transmitted from the transmitting antenna 21 to the receiving antenna 11 so that it may be transmitted to the digital doorlock 1. In addition, the data informing of recognition or operating status of the digital doorlock 1 is ASK-modulated by the first data transmitting/receiving unit 14 and then wireless-transmitted from the receiving antenna 11 to the transmitting antenna 21 so that it may be transmitted to a corresponding controller connected to the home network 30.
[31] The present invention has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. Industrial Applicability
[32] According to the present invention, power may be supplied to a digital doorlock by wireless, so the power supply of the present invention may be easily constructed, require less maintenance costs and cause no environmental problem, differently from the conventional one using a power cable or a battery.
[33] In addition, since the present invention allows power to be continuously supplied to the digital doorlock, sufficient power may be supplied though the system is configured to bi-directionally control the digital doorlock via a home network.