Figure 4-34: Waveform Crest Factor Affects Max. Rms Voltage - California Instruments MX30-1 User Manual

Mx series ac and dc power source series i / series ii

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User Manual – Rev AJ

The figure shown here illustrates the relationship between the crest factor of the wave sh

its "peakine

ss") and the maximum peak voltage allowed for a given voltage range. Since the

peak voltage cannot exceed the AC source's capabilities, th

be restricted, in this case to onl 167.8785 volt for the wavef

the right can be programmed to the full 300 V rms as this still falls within the same peak voltage

limitation of the AC source.

If the MX Series is used over the bus, the ":VOLT? MAX" query command can be used to

determine the maximum allowable RMS voltage for the selected waveform. Using the returned

value as part of a program will prevent range errors.

4.4.6 Frequency Response

The user may create a waveform that contains any number of harmonic frequencies of the

fundamental. The AC Source itself however has a finite signal bandwidth and will attenuate

higher frequency components of the signal. To limit the maximum frequency component of the

output signal, the 3Pi controller automatically applies a band-pass filter to all custom waveforms

as they are downloaded. The controller implements the following process for user defined

waveforms:

Each down loaded waveform will have a computed frequency limit that is less tha

maximum frequency limit of the AC source. The frequency limit is a function of the harmonics

content of the waveform and will follow the equation below.

Fmax

If F axh is below the minimum frequency limit, the waveform will be rejected at down load time

and the label will be deleted from the waveform catalogue.

If t e MX Series is used over the bus, the ":FREQ? MAX" query command can be used to

determine the maximum allowable fundamental frequency for the selected waveform. Using the

returned value as part of a program will prevent range errors.

Lim

its assume a program of full-scale voltage. No adjustments for voltage setting are made

belo

w the full-scale value.

veform selection and frequency programming will be subject to the above limit. A

message will be generated to reflect this type of error:

"22,Waveform harmonics limit"

Tra

nsient editing will also generate the above error during keyboard entry. Remote transient

entry will not check for the error until transient execution.

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