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In another embodiment, the local server 1 is connected to the coordinator 2 wirelessly. In this embodiment, the native server 1 issues a command to the coordinator 2 which executes the command by sending a corresponding data packet wirelessly to the good meters 3 by a radio frequency (RF) link, e.g. ZigBee which will or may not support an industry commonplace such as IEEE 802.14.5. Then the sensible meters 3 send an appropriate response back to the coordinator 2 by the identical RF link. The present invention is said usually to meters for measuring power and more significantly to a sensible meter system. The smart meter system 50 comprises an area server 1 linked to a coordinator 2 and good meters three (sensible meter 1-N). In a single embodiment, the local server 1 is connected to the coordinator 2 via wires. The good meter 3 contains a power supply 35, a battery backup 36, a liquid crystal show or LCD display 37, a RF controller System-on-Chip (SOC) 38, and voltage and current sensors 39. The battery backup 36 provides a non-interruptible power provide in the event of a power failure. The battery backup 36 permits the detection of power failure within the smart meter 3. The status of the battery backup 36 is reported in the Status register.

The local server 1 points commands to the coordinator 2 by means of a coordinator-server interface management register. The power usage could be accessed for instance by displaying internet pages utilizing any machine that is related to the native server or the internet. The facility utilization will also be analyzed to enable system management, e.g. cut off the facility if necessary. The database could be analyzed to find out optimum power utilization and distribution. But for non-resistive masses, corresponding to AC motors, the average AC energy will be calculated by the direct product of current and voltage averaged over a time frame. The average energy dissipated in resistive hundreds, e.g. household appliances, could be calculated as the product of root-imply-squares of current and voltage averaged over a time period. By eliminating the transformer the smart meter might be physically smaller, less pricey and will not be tampered as in the case when the transformer core is placed in a saturation condition.

Another advantage of using resistors and optically coupled isolators is the truth that voltage and present sensing's can't be tampered as within the case of transformers by inserting a powerful exterior magnets in the shut proximity as to saturate the transformer cores. The circuit designs for voltage and present sensing's and electrical isolation are disclosed. This bias condition enables the IR LED diode to function at a voltage bias condition to maximize the sensitivity of the optically coupled isolator and decrease the present consumption. The IF LED 9 is biased within the ahead conduction region utilizing a voltage source VB 8. This bias situation is decided by selecting a present-limiting resistor RD 10 that's equal to the distinction of bias voltage supply VB eight and the ahead voltage VF of the IR LED diode divided by the forward present IF of the IR LED diode. These voltages are optically coupled and electrically remoted to the inputs of the low voltage circuits through the use of optically coupled isolators. Using optically coupled isolators, the sensed voltages within the excessive voltage energy strains are optically coupled and electrically remoted to the low voltage circuits. Circuits for the voltage and current sensing method are described utilizing resistors and optically coupled isolators.

The method consists of coupling at the very least one resistor to a excessive voltage portion of the sensible meter. One widespread method to attain that's to use voltage and current transformers. FIG. 6 is an illustration of circuit for voltage sensing transistor in an open collector configuration with a load resistor connected to the collector. FIG. 3 is an illustration of circuit design for a current sensing portion of voltage and present sensors 39 in the smart meter 3 of FIG. 2 for a single-phase energy line system. The smart meter system 50 is a many-to-one information communication topology. Cite:Bochuan Wang, Xixiu Wu, Zhuqing Xia, Xin Yang, and Zhining Yang, "Research on the Characteristics of the Low Voltage Power Line Carrier Communication Channel," Journal of Advances in Computer Networks vol. Pat. No. 9,000,753, entitled "SMART METER VOLTAGE AND Current SENSING Using OPTICALLY COUPLED ISOLATORS", which is included herein by reference. A transformer-less method and system for voltage and current sensing utilizing voltage drops across resistors is disclosed. A sensible meter system voltage and current sensing are carried out as voltage drops throughout a shunt resistor in collection with the ability line or from a voltage divider linked throughout the ability strains. The method consists of coupling a resistor voltage divider to a high voltage portion of the good meter.