Consumers have been found manipulating their electric meters, causing them to stop, under-register or even bypassing the meter, effectively using power without paying for it. An energy meter is a device that measures the amount of electrical energy supplied to a
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a meter is the kilowatt hour, which is equal to the amount of energy used by a load of one kilowatt in one hour. Figure 1 shows a system block diagram for a three-phase energy meter. As shown the energy meter hardware includes a power supply, an analog front end, a microcontroller section, and an interface section. The analog front end is the part that interfaces to the high voltage lines. It converts high voltages and high currents to voltages sufficiently small to be measured directly by the ADC (Analog/Digital Converter) of the microcontroller. Voltage measurement is done with a shunt resister (shown as "Load"), while the current measurements require more precise measurement and thus are done by Current Transformer (CT) on all phases along with current measurement on neutral. Meter manufacturers often integrate gain amplifiers in order to amplify voltage as well as current measurements in the range supported by the ADC. The amount of amplification required depends on the ADC resolution as well as the Class accuracy (0. 1, 0. 2. 1. 0 etc. ) required for a three-phase meter. A typical energy meter also requires a Real Time Clock (RTC) for tariff information. The RTC required for a metering application needs to be very accurate (< 5ppm) for Time of Day (TOD), which involves dividing the day, month and year into tariff slots. Higher rates are applied at peak load periods and lower tariff rates at off-peak load periods. The...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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