Product Tutorials

Power Meter Tutorials

Measurement

Power and Energy Measurement

Switching Mode Power Supply

Switching Mode Power Supply is adopted to almost Household Appliances and Office Automation Equipment
The inputted current waveform is distorted like pulse wave and also voltage waveform is distorted same point as current. It includes so much harmonic components because of circuit design of capacitor input style.

Requirements for Power Meter;

Accurate measurement in case of large Crest Factor waveform
Wide frequency bandwidth up to components of distorted input waveform
Accuracy and Linearity in case of small current input

Inverter Driven Motor

Type of Inverter : PWM is main method and PAM becomes popular

PWM(Pulse Width Modulation) : Revolution speed of motor is controlled by using change of pulse width of voltage waveform. And there are two types of method in PWM. One is Sinusoidal PWM and another is Square-wave PWM. The Sinusoidal or Square- mean current waveform of motor input.

PAM(Pulse Amplitude Modulation) : Revolution speed is controlled by amplitude of voltage. And the waveform both voltage and current are square. Therefore, frequency bandwidth of measuring instrument for current is required higher than PWM type inverter.

Requirements for Power Meter;

Immunity against large and high frequency common mode voltage
Broad frequency bandwidth from DC to components of square waveform

High frequency fluorescent Lamp

Inverter for high frequency fluorescent lamp
In general, the waveform is a kind of triangle or sinusoidal. And the fundamental frequency is below 100kHz. Also envelope is twice of commercial frequency.

Requirements for Power Meter;

Immunity against large and high frequency common mode voltage
Broad frequency bandwidth from DC to components of carrier frequency
Small loss of instrument(high impedance of voltage input and low impedance of current input