FIG. 3 is an illustration of circuit design for current sensing transistor in an emitter follower configuration with load resistor related to the emitter. FIG. 6 is an illustration of circuit for voltage sensing transistor within the open collector configuration with a load resistor RL 69. An optical transistor sixty nine has a base terminal B that is optically coupled to the IF LED 66. The emitter terminal E is connected to the Vss terminal 71. The collector terminal C is linked to the second terminal of a resistor RL sixty nine within the open collector configuration. An optical transistor 57 has a base terminal B that's optically coupled to the IF LED which is a low voltage portion 102. The collector terminal C is connected to the VDD terminal 56. The emitter terminal E is connected to the primary terminal of a resistor RL fifty eight within the emitter follower configuration. An optical transistor 12 has a base terminal B that's optically coupled to the IF LED which is a low voltage portion 102. The collector terminal C is related to the VDD terminal 11. The emitter terminal E is linked to the first terminal of a resistor RL thirteen in an emitter follower configuration.
That is made attainable by optically isolating a excessive voltage portion of the smart meter from a low voltage portion. A smart meter system voltage and current sensing are performed as voltage drops throughout a shunt resistor in collection with the facility line or from a voltage divider related across the facility strains. Using optically coupled isolators, the sensed voltages in the high voltage power lines are optically coupled and electrically isolated to the low voltage circuits. The facility utilization might be accessed for example by displaying internet pages using any device that's connected to the native server or the web. In so doing, resistors might be utilized to supply the present or voltage sensing properties of the sensible meter. The facility usage will also be analyzed to enable system control, e.g. cut off the facility if vital. The smart meter 3 contains a power supply 35, a battery backup 36, a liquid crystal display or LCD display 37, a RF controller System-on-Chip (SOC) 38, and voltage and current sensors 39. The battery backup 36 offers a non-interruptible energy provide in the occasion of a energy failure. In a second facet, a way of sensing voltage inside a sensible meter is disclosed.
A transformer-less method and system for voltage and present sensing utilizing voltage drops throughout resistors is disclosed. A key function of the current invention is that there is no such thing as a need for a transformer when sensing voltage and current. There is a need to enhance system efficiency, reliability, testability and manufacturability of the smart meter during the product production and prototyping. Although the current invention has been described in accordance with the embodiments shown, certainly one of strange skill in the art will readily acknowledge that there may very well be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Various modifications to the preferred embodiments and the generic principles and options described herein will probably be readily apparent to these expert within the artwork. Thus, the current invention shouldn't be intended to be limited to the embodiments proven, however is to be accorded the widest scope per the rules and features described herein. To explain the options of the present invention in more element refer now to the next description along side the accompanying Figures. The next description is introduced to allow one in all peculiar skill within the artwork to make and use the invention and is offered within the context of a patent application and its necessities.
Accordingly, many modifications may be made by one in all unusual ability within the art without departing from the spirit and scope of the present invention. In this embodiment, the local server 1 points a command to the coordinator 2 which executes the command by sending a corresponding knowledge packet wirelessly to the good meters 3 by a radio frequency (RF) link, e.g. ZigBee that may or may not assist an industry customary such as IEEE 802.14.5. Then the smart meters 3 ship an appropriate response back to the coordinator 2 by the identical RF hyperlink. The local server 1 issues commands to the coordinator 2 by way of a coordinator-server interface management register. FIG. 7 is an illustration of circuit for voltage and present sensing for the emitter follower configuration for a 3-phase energy line software. The advantages of this transformer-much less methodology as compared to the transformer approach are direct sensing of present and voltage that allows AC power and energy measurements for non-resistive hundreds, tamper proof for secure energy measurements, compact sizes, and low costs. The system and technique must be easily carried out, value effective and adaptable to existing techniques. The smart meter system 50 is a many-to-one information communication topology.
