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The Tweet-a-watt [13] is a hacked version of the standard Kill-A-Watt Plug in Power Meter. By piggybacking on the device's on-board LM2902N op-amp chip, the creator was able to get readings for voltage and current and transmit to a computer, which then sent this to Twitter via handle @tweetawatt. [ 14 ]
In direct current (DC) circuits, this product is equal to the real power, measured in watts. [3] The volt-ampere is dimensionally equivalent to the watt: in SI units, 1 V⋅A = 1 W. VA rating is most used for generators and transformers, and other power handling equipment, where loads may be reactive (inductive or capacitive).
Fluorescent lamps in various embodiments. Since their introduction as a commercial product in 1939, many different types of fluorescent lamp have been introduced. Systematic nomenclature identifies mass-market lamps as to overall shape, power rating, length, color, and other electrical and illuminating characteristics.
For every hour of operation at the service-factor-adjusted power rating, a motor loses two to three hours of life at nominal power, i.e. its service life is reduced to less than half for continued operation at this level. [4] [10] The service factor is defined in the ANSI/NEMA MG 1 standard, [11] and is generally used in the United States. [12]
Some manufacturers released some 4000-series equivalent CMOS circuits with a 74 prefix, for example, the 74HC4066 [2] was a replacement for the 4066 with slightly different electrical characteristics (different power-supply voltage ratings, higher frequency capabilities, lower "on" resistances in analog switches, etc.).
The wattmeter is an instrument for measuring the electric active power (or the average of the rate of flow of electrical energy) in watts of any given circuit. Electromagnetic wattmeters are used for measurement of utility frequency and audio frequency power; other types are required for radio frequency measurements.
Two meters installed, main and check, both recording the same load. The main meter being used for billing. COP2 10MW to 100MW Two meters installed as in COP3, but higher-accuracy class meters. COP1 > 100MW Very few sites in the UK at this level, generally power stations and connections with the National Grid.
To test for a match, the reference impedance of the bridge is set to the expected load impedance (for example, 50 Ohms), and the transmission line connected as the unknown impedance. RF power is applied to the circuit. The voltage at the line input represents the vector sum of the forward wave, and the wave reflected from the load.