Abstract
The present invention involves utilizing AC power lines adapted for connection to an AC power source and a signal line to perform baseband signal transmission and communication. According to the invention, a threshold voltage is provided as a comparison reference for an AC input voltage to determine whether the communication is permitted. If the AC input voltage is greater than the threshold voltage, the communication is permitted. On the contrary, if the AC input voltage is smaller than the threshold voltage, the communication is not permitted. By virtue of the invention, the initiation time and the termination time of the baseband signal communication for each load tend to be substantially identical. Reliability is thus increased and noise interference problem is not created.
Claims
1. A power line-based communication device, comprising: an AC power input terminal having a first power line, a second power line and a signal line; a rectifying unit electrically connected to the AC power input terminal; a voltage comparison module adapted to receive an AC input voltage through the rectifying unit and set with a threshold voltage for comparing with the AC input voltage; and a signal transmission interface connected to the voltage comparison module and the signal line, respectively.
2. The device according to claim 1, wherein the rectifying unit is a half-wave rectifier electrically connected to the first power line, and the voltage comparing module is electrically connected at its one end to the half-wave rectifier and electrically connected at the other end to the second power line.
3. The device according to claim 1, wherein the rectifying unit is a full-wave rectifier electrically connected to the first and second power lines, respectively, and the voltage comparison module is electrically connected to the full-wave rectifier.
4. The device according to claim 1, wherein the voltage comparison module comprises a setting unit for setting the threshold voltage value, and a comparison unit electrically connected to the setting unit for comparing the threshold voltage value with the received AC input voltage.
5. The device according to claim 4, further provided with a micro-processor unit adapted for electrical connection to a load, wherein the micro-processor unit is electrically connected to the signal transmission interface.
6. The device according to claim 4, wherein a non-isolated power conversion unit is further provided and electrically connected to the rectifying unit and the voltage comparison module, respectively.
7. The device according to claim 4, wherein at least one isolation unit is further provided for connection to the signal transmission interface.
8. The device according to claim 2, wherein the voltage comparison module comprises a setting unit for setting the threshold voltage value, and a comparison unit electrically connected to the setting unit for comparing the threshold voltage value with the received AC input voltage.
9. The device according to claim 8, further provided with a micro-processor unit adapted for electrical connection to a load, wherein the micro-processor unit is electrically connected to the signal transmission interface.
10. The device according to claim 8, wherein a non-isolated power conversion unit is further provided and electrically connected to the rectifying unit and the voltage comparison module, respectively.
11. The device according to claim 8, wherein at least one isolation unit is further provided for connection to the signal transmission interface.
12. The device according to claim 3, wherein the voltage comparison module comprises a setting unit for setting the threshold voltage value, and a comparison unit electrically connected to the setting unit for comparing the threshold voltage value with the received AC input voltage.
13. The device according to claim 12, further provided with a micro-processor unit adapted for electrical connection to a load, wherein the micro-processor unit is electrically connected to the signal transmission interface.
14. The device according to claim 12, wherein a non-isolated power conversion unit is further provided and electrically connected to the rectifying unit and the voltage comparison module, respectively.
15. The device according to claim 12, wherein at least one isolation unit is further provided for connection to the signal transmission interface.
16. The device according to claim 1, further provided with a micro-processor unit adapted for electrical connection to a load, wherein the micro-processor unit is electrically connected to the voltage comparison module and the signal transmission interface, respectively.
17. The device according to claim 2, further provided with a micro-processor unit adapted for electrical connection to a load, wherein the micro-processor unit is electrically connected to the voltage comparison module and the signal transmission interface, respectively.
18. The device according to claim 3, further provided with a micro-processor unit adapted for electrical connection to a load, wherein the micro-processor unit is electrically connected to the voltage comparison module and the signal transmission interface, respectively.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a structural schematic diagram of a communication device according to the first embodiment of the invention;
[0018] FIG. 2 is a structural schematic diagram of a communication device according to the second embodiment of the invention;
[0019] FIG. 3 is the signal waveform diagram according to the second embodiment of the present invention;
[0020] FIG. 4 is a structural schematic diagram of a communication device according to the third embodiment of the invention;
[0021] FIG. 5 is the signal waveform diagram according to the third embodiment of the present invention;
[0022] FIG. 6 is a structural schematic diagram of a communication device according to the fourth embodiment of the invention;
[0023] FIG. 7 is a structural schematic diagram of a communication device according to the fifth embodiment of the invention;
[0024] FIG. 8 is a structural schematic diagram of a communication device according to the sixth embodiment of the invention;
[0025] FIG. 9 is a structural schematic diagram of a communication device according to the seventh embodiment of the invention;
[0026] FIG. 10 is a structural schematic diagram of a communication device according to the eighth embodiment of the invention; and
[0027] FIG. 11 is a schematic diagram showing the communication device according to the invention in use.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The communication method according to the invention mainly involves utilizing AC power lines adapted for connection to an AC power source and a signal line to perform baseband signal transmission and communication, wherein a threshold voltage is set as a comparison reference for an AC input voltage to determine whether the communication is permitted. FIG. 1 is a structural schematic diagram showing a communication device according to the first embodiment of the invention. According to the invention, a power line-based communication device 100 comprises an AC power input terminal 1, a rectifying unit 2, a voltage comparison module 3 and a signal transmission interface 4, wherein the AC power input terminal 1 has a first power line 11, a second power line 12 and a signal line 13. The rectifying unit 2 is electrically connected to the AC power input terminal. In the second embodiment shown in FIG. 2, the rectifying unit may be a half-wave rectifier 21 electrically connected to the first power line 11.
[0029] The voltage comparison module 3 comprises a voltage dividing unit 31, a setting unit 32 and a comparison unit 33. The comparison unit 33 is electrically connected to the voltage dividing unit 31 and the setting unit 32, respectively. The voltage comparison module 3 receives an AC input voltage from the AC power input terminal 1 through the rectifying unit 2 and divides the voltage to generate a divided voltage signal. According to the second embodiment shown in FIG. 2, one end of the voltage comparison module 3 is electrically connected to the half-wave rectifier 21 and the other end thereof is electrically connected to the second power line 12, and the setting unit 32 of the voltage comparison module 3 is set with a threshold voltage (Vth) for comparison with the AC input voltage.
[0030] According to the embodiment shown in FIG. 2, in the case where the rectifying unit is a half-wave rectifier 21, the signal level reference ground is fixedly connected to the second power line 12. Referring to the signal waveform diagram shown in FIG. 3, when the AC power is input through the AC power input terminal 1, the AC power is rectified by the half-wave rectifier 21, and the rectified power is transmitted to the voltage comparison module 3 for comparison to obtain a communication cycle time including a duty time t1 and a forbidden time t2. The communication cycle time is an AC cycle, and the communication frequency is a multiple of the AC frequency. The duty time t1 is the time in which the AC input voltage is greater than the threshold voltage. The voltage level is clear, allowing the signal transmission interface 4 to communicate. The signal transmission interface 4 can proceed with transmission and communication of baseband signals through the signal line 13. The forbidden time t2 is the time in which the AC input voltage is lower than the threshold voltage. The voltage level is unclear, prohibiting the signal transmission interface 4 to communicate.
[0031] According to the third embodiment shown in FIG. 4, the rectifying unit is a full-wave rectifier 22 electrically connected to the first and second power lines 11, 12, respectively. The voltage comparison module 3 is electrically connected to the full-wave rectifier 22, whose signal level reference ground is in compliance with the AC power to correspond to the first and second power lines 11, 12 through the full-wave rectifier 22. When the input AC is in the positive half-wave, the signal level reference ground is located on the second power line 12. When the input AC is in the negative half wave, the signal level reference ground is located on the first power line 11. Referring to the signal waveform diagram shown in FIG. 5, when the AC power is input through the AC power input terminal 1, the full-wave rectifier 22 functions for rectification to transmit the rectified power to the voltage comparison module 3 for comparison. After comparison, a communication cycle time including a duty time t1 and a forbidden time t2 is obtained, wherein the communication cycle time is an AC cycle, and the communication frequency is a multiple of the AC frequency. The duty time t1 is the time in which the AC input voltage is greater than the threshold voltage. The voltage level is clear, allowing the signal transmission interface 4 to communicate. The signal transmission interface 4 can proceed with transmission and communication of baseband signals through the signal line 13. The forbidden time t2 is the time in which the AC input voltage is lower than the threshold voltage. The voltage level is unclear, prohibiting the signal transmission interface 4 to communicate.
[0032] Referring to FIG. 6, which is a structural schematic diagram showing a communication device according to the fourth embodiment of the invention. The voltage dividing unit of the voltage comparison module 3 can be two resistors 311 connected in series, which are electrically connected to the full-wave rectifier 22 to achieve voltage dividing effect. The use of field-effect transistors (MOSFET) 312, in conjunction with Zener diodes 313, constitutes a comparison unit that can proceed with comparison of the AC input voltage with the threshold voltage value to determine the period during which communication is permitted. This embodiment may use a higher voltage signal for communication to facilitate the signal level judgment.
[0033] Referring to FIG. 7, which is a structural schematic diagram showing a communication device according to the fifth embodiment of the invention. The embodiment herein is further provided with a microprocessor unit 5 for electrical connection to a load 8. The microprocessor 5 is electrically connected to the signal transmission interface 4, and the communication and transmission of baseband signals are performed by directly using the TTL I/O pins of the microprocessor 5 for transmission and reception. According to the embodiment shown in FIG. 7, a non-isolated power conversion unit 6 may be further provided. The non-isolated power conversion unit 6 is electrically connected to the rectifying unit and the voltage comparison module 3, respectively, and adapted to convert the rectified AC power into DC power. According to the embodiment shown in FIG. 7, a rectifier diode 61 connected in series with a resistor 62 is arranged downstream the full-wave rectifier 22 for voltage reduction, and a Zener diode 63 connected in parallel to a capacitor 64 is arranged downstream the resistors, which constitute a non-isolated power conversion unit 6 for providing a simple DC power source. The non-isolated power conversion unit herein is provided for illustrative purpose only, and other non-isolated power conversion architectures known in the art are also applicable in the invention.
[0034] Referring to FIG. 8, which is a structural schematic diagram showing a communication device according to the sixth embodiment of the invention, whose structure is substantially the same as that of the fifth embodiment. The only difference is that in the sixth embodiment, the voltage comparison function is performed by an operational amplifier 314 in conjunction with the Zener diodes 313 to give a reference voltage, which constitutes a voltage judgment loop.
[0035] Referring to FIG. 9, which is a structural schematic diagram showing a communication device according to the seventh embodiment of the invention, whose structure is substantially the same as that of the sixth embodiment. The only difference is that in the seventh embodiment, no processor unit is provided. Instead, at least one isolation unit 7 (which may by way of example be an optical coupler or a signal coupler) is provided. The isolation unit 7 is electrically connected to the signal transmission interface 4, and the TX/RX/INT ports of the signal transmission interface 4 are respectively connected to an isolation unit 7 for isolation from the rear control system.
[0036] In said embodiment, part of the functions of the voltage comparison module (such as the function of controlling the communication cycle, etc.) is performed by a microprocessor unit. Referring to FIG. 10, which is a structural schematic diagram showing a communication device according to the eighth embodiment of the invention. The voltage comparison module is provided with a voltage dividing unit, which may be two series-connected resistors 311. In the same manner, the AC input voltage from the AC power input terminal 1 is received through the rectifying unit (with full-wave rectifier 22 as an example in this embodiment) and divided to generate a divided voltage signal. In addition, the microprocessor unit 5 is electrically connected to the voltage comparison module 3 and the signal transmission interface 4, respectively, and adapted for electrical connection to a load 8. The divided voltage signal obtained by the voltage dividing unit is transmitted to the input pins of the microprocessor unit 5 having A/D function; the internal A/D function of the microprocessor unit 5 is used to judge the voltage position, and the software program built in the microprocessor unit 5 is used to control the communication cycle of the signal transmission interface 4.
[0037] The present invention involves a baseband signal transmission and communication by using AC power lines adapted for connection to an AC power source and a signal line, which can be applied to a load that needs to receive mains supply. As shown in FIG. 11, the invention may be applied to a light source 81 (such as a light emitting diode lamp), a sensor, or a display, etc. While the electricity is transmitted, baseband signal communication can also proceed. A user is allowed to directly accomplish smart remote control simply by connecting each load to a conventional three-wire connector. Taking the light sources 81 as an example, a control system 9 can be electrically connected in series to a plurality of light sources 81 through the power lines 11, 12, and each light source 81 is electrically connected to the power lines 11, 12 through the communication device 100 of the invention. Users can preset various control modes via the control system, such as turning on or turning off the light source and adjusting brightness of the light source. The control system can convert various control modes into baseband signals, and the power line is used for transmission of the baseband signal, which is not only capable of controlling on or off of the light source or evening dimming by using the power line, but also has the advantages of achieving wide coverage, easy connection and high transmission rate by using existing wires. Comparison of the threshold voltage value with the AC input voltage to determine the communication cycle makes the communication cycle of the baseband signals counted from its initiation to termination to be substantially identical for each light source, thus greatly improving the reliability and ensuring that the AC input voltage can be developed to sufficiently high signal level in order to ensure that the equivalent impedance of the rectifying unit meets the transmission requirement of baseband signals.
[0038] It is worthwhile to note that compared with the traditional powerline communication (PLC) technology, the invention utilizes a signal line incorporated in the power lines for data transmission rather than directly loading signals on the power lines, which not only improves the noise interference problem of power line communication, but also spare the use of isolation system and modulation/demodulation system to achieve a simpler system configuration.
