PASCO PI-9880 Power Supply - Manual (Page 25)

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M o d e l N o . P I - 9 8 8 0 0 1 2 - 1 2 6 9 5 A S t a n d a r d F u n c t i o n s ( R e c t a n g l e ,
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Ramp
Ramp Parameters
The Ramp function has four parameters: Maxi-
mum Voltage, Minimum Voltage, Period, and
Auto-repeat.
The Auto-repeat parameter determines the
total number of cycles that are output before
the function stops. For indefinite repetition, set
Auto-repeat to zero.
The signs of the Period and Auto-repeat
parameters (
+ or −) determine the shape of the
wave. The Period is positive for an ascending
ramp or negative for a descending ramp. The
Auto-repeat parameter is positive for a saw-
tooth wave or negative for a triangle wave, in
which ascending and descending ramps alternate. Set Auto-repeat to “
−0” for an
indefinitely repeating triangle wave.
Some examples of Period and Auto-repeat settings with their resulting waveforms are
illustrated below.
Ramp Set-up
1. Turn the Function knob to . The display shows the Maximum Voltage
parameter, and the Voltage LED blinks slowly to indicate that the Power Supply
is in set-up mode with no output. Turn the Coarse and Fine knobs to set the Max-
imum Voltage.
2. To set the Minimum Voltage, press and hold (SET) until the Voltage LED
starts blinking fast. While holding the button, turn the Coarse and Fine knobs.
Release the button.
Period
Minimum
Voltage
Maximum
Voltage
Period Auto-
repeat
Waveform Comments
1.3 0
The sign of Period determines whether the
ramp is ascending (
+) or descending (−).
Auto-repeat is set to zero for indefinite
repetition.
−1.3 0
1.3 2
The sign of Auto-repeat determines whether
the wave is sawtooth (
+) or triangle (−).
Period and Auto repeat set the length and
number of
full cycles. For a triangle wave, a
full cycle consists of an ascending and a
descending ramp.
1.3 −2
2.6 −2
2.6 −0
Ramp Defaults:
Max. Voltage 18 V
Min. Voltage 0 V
Period 10 s
Auto-repeat 0