Power analysis option for digital oscilloscopes
YOKOGAWA has introduced a new power analysis option for its DL7400 series of 500MHz digital oscilloscopes. The DL7400 series already offers up to eight analogue channels, up to 16 logic inputs and very long memory (up to 16 Mword).
Now with the new power analysis option, users of the DL7400 can use a digital oscilloscope to make advanced power and power-related measurements.
The power analysis option is designed to easily and quickly make complex power and power-related measurements on devices such as switching power supplies, converters, inverters, motors, electronic ballasts, etc.
The strengths of making power measurements using the DL7400 are many:
* First, the DL7400 offers up to eight analogue channels and up to 16 logic inputs - this means you can even monitor three phases of input, three phases of output and many control signals simultaneously using one instrument.
* Second, the 500MHz analogue bandwidth and 2GS/s sampling speed allows for more accurate measurement of fast-switching devices as compared to traditional power analysers.
* Third, the instrument's long memory (up to 16 Mword) means that waveforms from startup to steady state behavior can be captured at high sampling rates.
* Fourth, by using the oscilloscope's X-Y display format, you can view a device's area of safe operation (ASO) or safe operating area (SOA).
Probe deskew is especially important for measurements on devices with fast switching speeds. Accounting for differences in electrical lengths between voltage and current probes is extremely easy when using the DL7400 power analysis option.
Using the optional 701935 Deskew Signal Source (which supplies a current and voltage signal with aligned raising/falling edges), you can automatically deskew a channel with the push of one button.
With the DL7400 power analysis option users can define scope channels to either measure voltage or to measure current. For each channel, users select either the voltage probe attenuation or the current-to-voltage conversion ratio of the current probe.
The instrument then automatically displays the measurement waveform in the appropriate units (e.g., V, A, mA). For each voltage or current-defined channel you have the ability to utomatically display voltage, current and power waveform parameters.
The Power Analysis Option also adds special math waveform options that are not possible on the standard DL7400. In addition to displaying real-time power, impedance, I2t, and FFT waveforms, the power analysis option as the ability to display current harmonics and waveform parameter trends.
With the harmonic analysis function, users can test your device to IEC 61000-3-2 limits. The instrument displays measured current harmonics up to the 39th or 40th harmonic, depending the on the class of device, A, B, C, D. Additionally, IEC harmonic limit values are displayed, along with other necessary information such as measured value as a percent of fundamental and as a percent of the IEC limit.
Measured and limit data can be displayed graphically or in tabular format on the screen and can be saved in ASCII format for exporting to a PC.
The unique math trend analysis makes use of the DL7400's Cycle Statistics function to display waveform parameter trends as they change over time. The Cycle Statistics function takes an acquired waveform and calculates waveform parameters (such as peak-to-peak voltage or frequency) for each cycle.
The data is then tabulated and statistical information such as max, min, average and standard deviation and number of cycles is displayed. The new math trend function in the power analysis option then plots out Cycle Statistics information on the screen so that changes in parameters over time are displayed.
For example, this feature would plot out changes in switching frequency of a power supply as it goes from turn-on to steady state.
4-Sep-2003