PM100 / 300 U
SER
M
ANUAL
T
HE
MENU S
YSTEM
VPN 98-052 P
AGE
19
A
PPLICATIONS
E
XAMPLE
– L
OW
-P
OWER
S
TANDBY
M
EASUREMENTS
.
An ac power supply is equipped with a low-power standby mode. In this mode, current is drawn
from the supply in ‘bursts’ that occur every 300ms or so. The waveform is shown below.
A measurement of the average input power is required to check the rating of the power supply.
With default settings, the PM100 makes measurements at high speed and updates the display
approximately every ½ second. With the waveform above, the measurements are not stable, and
the analyzer pauses while it auto-ranges in between readings.
To make stable average measurements, follow this procedure.
1. Measure the peak current.
In normal power on mode, press the
[A]
key and then the
[PEAK]
key. Amps peak will be
displayed. In this example, the maximum reading was approximately –750mA.
2. Set up a fixed current range.
Press [MENU], [1] and then [] until you see:
MANUAL A RANGE
x >
9
<
and then enter the nominal peak current, ignoring the (-) sign:
PEAK CURRENT
>0.750<
3. Now set up long averaging in
[MENU]
,
[2]
.
LONG AVERAGING
x >
9
<
To Next Page
Loading...
Need help?
General
