Technical data

Service and Maintenance 8

Constant Voltage (CV) Verifications

E364xA User’s and Service Guide 191

CV PARD (ripple and noise)

Periodic and random deviations (PARD) in the output (ripple

and noise) combine to produce a residual AC voltage

superimposed on the DC output voltage. CV PARD is

specified as the rms or peak- to- peak output voltage in the

frequency range from 20 Hz to 20 MHz.

Vrms measurement techniques

When measuring Vrms ripple and noise, the monitoring

device should be plugged into the front of the terminals at

(A) in Figure 8- 2. Use the vertical mini- probe socket and

the 1:1 voltage probe to connect the monitor device to the

power supply. To reduce the measurement error caused by

common mode noise, it is recommended to twist the

connection wire between the mini- probe and the output

terminals. The load resistor is connected to the terminal at

(B) in Figure 8- 2. Twisted leads between the load resistor

and the power supply help reduce noise pick- up for these

measurements.

Figure 8-3 Front/rear panel terminal connections for the Vrms measure-

ment

Load resistor

Rms voltmeter

(Front Panel Connections)

(Rear Panel Connections)

BNC cable

BNC

receptacle

Split ferrites*

Input

Load resistor

Input