Page 301 - Electrician - TT (Volume 1)

ELECTRICIAN - CITS

Fig 6
3 3-element 4-wire type Un balanced
loads.

Digital Wattmeter

Objectives: At the end of this lesson you shall be able to:
• describe the block diagram.

Digital wattmeter

The wattmeter is an instrument for measuring the electric power in watts of any given circuit. Electromagnetic
wattmeters are used for measurment of utility frequency and audio frequency and audio frequency power; other
types are required for radio frequency.
Fig 1 shows the block diagram of digital wattmeter.
Digital wattmeters measure current and voltage electronically thousands of times a second, multiplying the results
in a computer microcontroller chip to determine watts. The computer can also perform statistics such as peak,
average, low watts consumed. They can monitor the power line for voltage surges and outages. Digital electronic
wattmeter, have become popular for conveniently measuring power consumption in household appliances with
saving energy and money.

Fig 1

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CITS : Power - Electrician & Wireman - Lesson 50-53