PASCO PI-9880 User manual

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DC Programmable Power Supply
PI-9880
Instruction Manual
012-12695A
*012-12595*

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DC Programmable Power Supply 012-12695A
2

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Model No. PI-9880 012-12695A
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DC Power Supply Table of Contents
Contents
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Typical Uses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Specifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Tutorial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Basic Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Standard Functions (Rectangle, Ramp, and Stair) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Custom Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

DC Programmable Power Supply
PI-9880
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5
Introduction
The PI-9880 DC Programmable Power Supply sources 0–18 volts (V) at up to 1 ampere (A). You can use the
Power Supply as a simple constant-voltage source, or take advantage of its advanced features to output periodic
functions and custom programs.
Included Equipment Part Number
DC Programmable Power Supply PI-9880
AC Power Adapter (100 - 240 VAC, 24 VDC) 540-102

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DC Programmable Power Supply 012-12695A Typical Uses
6
Typical Uses
The Programmable Power Supply works well with a variety of electronic circuits,
motors, lamps, heaters, and Peltier devices, and the PASCO apparatus listed below.
Specifications
Model Number Name Comments
ET-8499 Calorimeter Set the Power Supply’s Stair function for a single heat pulse (see
page 26).
EM-8678 Charge/Discharge Circuit Use the Power Supply to charge the circuit’s capacitor or battery. Set the
Power Supply’s maximum voltage to 5 V (see page 20).
ET-8782 Thermoelectric Circuit Set the Power Supply’s maximum voltage to 10 V (see page 20).
ME-8088 Centripetal Force
Apparatus
Use the Power Supply’s ramp function (see page 23) to slowly increase
the rotational speed.
ME-8750 Mechanical Oscillator
Driver
Drive dynamics carts (such as ME-6950) or the Chaos/Driven Harmonic
Accessory (CI-6689A).
ME-8955 Rotational Motor Drive Drive the Rotating Platform (ME-8951) with the Magnetic Levitation
Accessory (EM-8947) or Rotational Acceleration Tank (ME-8957).
TD-8513 Heat Conduction Apparatus Power the apparatus with a positive-offset rectangle wave (see page 22)
or sine wave (the Power Supply’s default custom program, see page 28).
General Specifications
Output Voltage Adjustment 0–18 V
Voltage Adjust Resolution 10 mV
Voltage Adjust Accuracy 0.25% of setting or 20 mV, whichever is larger
Current-limit Shutdown Programmable, 0.010–1.050 A
Current Measurement Accuracy 3%
Load Regulation 1%
Output Noise 20 mV peak-to-peak typical, 60 mV peak-to-peak at full load
Function-specific Specifications
Function 1: Constant DC Output
(see page 19)
Monitor voltage or current, or cycle with adjustable time
Function 2: Rectangle Wave
(see page 22)
Programmable maximum voltage
Programmable minimum voltage
Programmable period: 0.1–999 s
Programmable duty cycle: 1–99%, Jitter: ±300 μs
Monitor voltage or current
Function 3: Ramp
(see page 23)
Programmable maximum voltage
Programmable minimum voltage
Programmable period: 0.1–999 s
Programmable ramp direction (ascending or descending)
Alternating ramp direction option (triangle wave)
Programmable number of cycles: 1 to 999, or infinite
Monitor voltage or current

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Model No. PI-9880 Specifications
7
Combining Two Units Two or more Programmable Power Supplies can be con-
nected in series. Connect the negative terminal of one unit to the positive terminal of
the other.
Excessive voltage levels can be achieved when combining units in this way; students
should do so only under the supervision of a qualified instructor.
Storage For easy storage of multiple units, indentations in the Programmable
Power Supply accept the feet of an identical unit stacked on top of it.
Function 4: Stair
(see page 25)
Programmable maximum voltage
Programmable step voltage: 0.01–18.00 V
Programmable minimum voltage
Programmable step time: 0.1–999 s
Programmable stair direction (ascending or descending)
Alternating stair direction option
Programmable number of cycles: 1 to 999, or infinite
Monitor voltage or current
Function 5: SET MAX
(see page 20)
Programmable voltage limit: 0.01–18.00 V
Programmable maximum current: 0.010–1.050 A
Automatic shutdown timer: 0.01–99.99 hours
“Hidden” Global Maximum voltage: 0.01–18.00 V (remembered after power off)
Function 6: PROGRAM
Custom program entry
(see page 28)
3–99 programmable voltage points (remembered after power off)
Edit modes: append, insert, delete point, delete entire program
Function 7: PLAY
Custom program output
(see page 29)
Programmable scale factor: 1–100% of programmed voltage
Programmable step-time: 0.1–999 s
Step-style and vector-style options
Programmable play direction (forward or backward)
Alternating play direction option
Programmable number of cycles: 1 to 999, or infinite
Monitor voltage or current

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DC Programmable Power Supply 012-12695A Specifications
8
Experiment-design Considerations Please note the following properties of
the Programmable Power Supply when planning an application:
• The Power Supply is over-current protected, but it is not current-limited or
current-regulated. If the maximum output current (1 amp by default, or lower if
you have changed the maximum-current setting) is exceeded, the Power Supply
will need to be manually reset before operation can resume. See “Over-current”
on page 20.
• The output voltage range is 0 to 18 V. To achieve a negative voltage switch the
positive and negative leads.
• This device is a programmable power source, not a function generator. The max-
imum frequency of the rectangle and ramp functions is 10 Hz. The maximum fre-
quency of the default sine-wave custom program is about 0.1 Hz.
• The Power Supply is designed for current flow in one direction: out of the posi-
tive terminal and into the negative terminal. In the example illustrated below, the
Power Supply is switched from 0 V to 5 V, then back to 0V. The capacitor does
not discharge in a predictable way because there is not a simple path to ground.
To provide a path to ground, connect a resistor across the Power Supply’s
terminals as shown.
A current-sinking resistor is not typically required when driving motors, lamps
and heating resistors since these devices have a low DC resistance.
Power
Supply
+
-
100 mF
100 W
100 mF
100 W
Power
Supply
+
-
20 W

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9
Tutorial
This tutorial will introduce you to the DC Programmable Power Supply. As you follow the steps, it will
be helpful to measure and view the Power Supply’s voltage output. Here are three possible ways to do
that:
1. Use a data-acquisition program such as DataStudio with a voltage sensor. The sample waveforms
shown in the tutorial were collected in this manner.
2. Use an digital storage oscilloscope capable of displaying several second’s worth of data.
3. Use a normal volt meter. This option will not allow you to reproduce the graphs on the following
pages, but you will be able to observe the variation of the Power Supply’s output.
If possible, connect a load resistor (or other device such as a small light bulb) to the output so that you
can look at the current draw. You can use any resistor from about 20 Ω to 100 Ω, but check the power
rating to make sure it will not overheat; during the tutorial, you will apply voltages up to 10 volts.
Set-up
POWER and OUTPUT connections
1. Plug the AC adapter into a wall outlet and
into the port labeled POWER on the Power
Supply.
2. Use a pair of banana-plug patch cords to
connect a load resistor (or other device) to
the Power Supply’s red (+) and black (−)
OUTPUT ports.
3. Connect a voltage sensor, meter, or oscillo-
scope to the OUTPUT ports.
Buttons
4. Notice the two buttons: and . You will
use these buttons, along with the knobs, to
control the Power Supply’s output and dis-
play.
Load factory settings
5. Push and hold both buttons. While holding
the buttons, turn on the power switch (if it is
already on, turn it off and on again). Con-
tinue to hold both buttons until the display
shows LLLL, then release the buttons. The
original factory settings have been loaded.

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DC Programmable Power Supply
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Tutorial
Function 1: DC Voltage
The Function knob
1. Turn the Function knob to the Constant DC
position ( ). The display briefly shows F1
(for “Function 1”), then 0.00 (for zero volts).
The Voltage LED is lit, indicating that the
quantity displayed is voltage in units of
volts.
Set voltage
2. Turn the Coarse knob to set the voltage to
4.00 V. Note that the displayed voltage
reflects the actual voltage at the output ter-
minals.
Turn the Fine knob. If you rotate it slowly,
the voltage changes by 0.01 V per detent. If
you rotate the knob more quickly, it changes
by 0.04 V per detent. Adjust the voltage back
to 4.00 V.
Temporarily switch off output
3. Quickly press and release to temporarily
switch off the output. The Voltage LED
blinks rapidly, and the actual output voltage
drops to zero, though the display still shows
the voltage setting.
Turn the Coarse knob. Note that you can
adjust the voltage setting while the actual
output remains zero. Return the voltage set-
ting to 4.00 V
Press to switch the output back on. The
Voltage LED is now on steadily to indicate
that the output voltage is live.
SET
MAX
PLAY
PROGRAM
FUNCTION
Constant
DC
Rectangle
Wave
Ramp Stair
Set Ma imum
Values
Enter
or Edit
Custom
Program
Play
Custom
Program
Voltage
LED blinks
rapidly.
Quickly
press and
release.