How
to use a signal generator “W.Gen”
W.Gen
1. Items
2. Connections
3. Power on
4. Control
5. Tasks
Faculty of Education, Chiba University Tetsuya Kato, Prof. Dr.　Ver.20120719
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1.1 Item list : 1 to 10
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†: in the drawer, *: in the PDL toolbox for mechanics
*
†
*
†
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1.1 Item list : 1 to 10
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†: in the drawer, *: in the PDL toolbox for mechanics
1†. a Digital Multimeter (DMM)
2†. a pair of test leads
with alligator clips and banana plugs
Plug in
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1.1 Item list : 1 to 10
●
†: in the drawer, *: in the PDL toolbox for mechanics
3†. a steel base plate
4*. a signal generator “W.Gen”
5*. its optional display
6†. an AC/DC adapter
(AC100 V→DC 5 V)
7*. an extension cable
for the adapter
Connect here
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1.1 Item list : 1 to 10
●
†: in the drawer, *: in the PDL toolbox for mechanics
8*. a paper cup (or a plastic cup)
9*. an electromagnet (a coil)
10†. a piece of magnet
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2.1 Connection of an optional display
●
You need to make ready the generator and its optional
display.
●
First, find a tip at the end of the cord from the
display.
●
Put the tip in a connector on the side of the generator.
connector
●
tip
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2.2 To work the signal generator
●
The generator has no power switch. Instead, you can
turn on and off its power by putting on and off the
connectors between the generator and the extension of
the adapter.
●
First you need to turn it off.
off
OFF
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2.3 Two types of output
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The generator makes two outputs with a frequency.
yellow-black pair
of wires
blue-black pair of wires
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2.3 Two types of output
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Take a pair of test leads, one end as the banana plug
(= put in the V (or mV) and COM holes of the DMM)
and the other end as the alligator clip.
●
Put their alligator clips on the ends of the blue and
black wires of the generator.
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2.5 Two types of output
●
An output of a blue-black pair of wires changes like a
wave. People say that its shape is sinusoidal. The
current of this output is small.
voltage
blue-black pair of wires
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time
2.5 Two types of output
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Another output is on a yellow-black pair of wires,
keeping 5 V in half the time and 0 V in the rest.
●
People say that
its shape is
voltage
rectangular.
The current of
●
this output is
large.
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time
2.5 Connection of yellow-black rectangular output (large current)
●
You use the output of the yellow-black pair of wires
to making magnetic force.
●
The electromagnet with the rectangular current will
repeat pulling and releasing a magnet nearby.
S
5V
N
S
0V
N
pulled
yellow-black pair of wires
N
S
released
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2.5 Connection of yellow-black rectangular output (large current)
●
Put a magnet in a paper cup. Place the electromagnet
to attract it over the paper cup.
●
Next is the last check before powering on.
magnet
coil
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3 Check points and powering on
●
You must check whether or not the conductors of
the cables touch each other or the steel part of the
base plate.
When the cables connect wrongly, the machines
cannot work, and they can even be broken.
If it is OK, plug in the adapter.
●
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3 Check points and powering on
Put on the connectors between the generator and the
●
adapter to turn on the power of the generator.
OFF
ON
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3 Check points and powering on
●The generator always shows a default value of
199.00 just after putting it on.
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4.1 Adding and subtracting
●
There is a button with four places
to push near to “up”,
up “down”,
down
“inc”(increase)
and
inc
“dec”(decrease).
dec
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You can think like this:
“up”
up = +1 :add one to the digit
“inc”=
inc
, “dec”=
dec
:change the selection of the place
“down”
down = -1 :subtract one from the digit
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4.2 Display in control: Right-side as a digit
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The optional display shows two numbers.
●
Look at the right-side number in the display. Read the
frequency on the DMM. And press “up”
up (+1) or
“down”(-1).
Repeat them.
down
●
This number is the digit that you changed.
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4.3 Display in control: Left-side as a place
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The left-side of the optional display can be “ 7”, “6”,
… , “1”, “-”, or “=”. Each one means the place of the
digit. For example, “2” is a ten's place, “1” is a one's
place, “-” is a first decimal place, and “=” is a second
decimal place.
●
You can change it by pressing“inc”
inc or “dec”.
dec
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4.4 Emulator of “W.Gen”
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You can use an emulator of “W.Gen” signal generator
with Web browser on your computer, going to
http://www.edu.chiba-u.jp/ssc/SciExpEng/WGenTest/.
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4.5 Control example 1
Disconnect and then connect the extension cable
of the adapter for the generator to reset the value.
● Press “dec”, then “inc”. This changes nothing but
dec
inc
calls the optional display to be the control mode. Then
the display is “1 9”, and the frequency is 199.00 Hz
(default value).
●
●
Press “inc”,
inc “up”,
up then “up”.
up The display “2 1”, the
frequency 219.00 Hz.
●
Press “inc”,
inc “up”,
up then “up”.
up The display “3 4”, the
frequency 419.00 Hz.
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4.6 Control example 2 and Test
Disconnect and then connect the extension cable
of the adapter for the generator to reset the value.
●
Press “dec”.
dec Then the display is “- 0”, and the
●
frequency is 199.00 Hz. (default frequency)
●
Press “down”.
down The display “- 9”, the frequency
198.90 Hz.
●
Press “inc”,“
inc up”,
up then “up”. The display “1 0”, and
the frequency 200.90 Hz.
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5.1 Test to hear sounds
●
Set the frequencies at just 50, 100, 200, 400, 800,
1600 Hz and find their differences.
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Set the frequencies at 10, 5, 2, 1, 0.5 Hz and try to
hear the sounds.
●
Set the frequencies at 5000, 10000 Hz and higher,
and try to hear the sounds.
●
Describe what you heard or how you felt when you
listened to those sounds. (日本語可)
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5.2 [Group work] Musical harmonies
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Make a group of four people to work together.
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Put four magnets in a paper cup and place four coils
to attract each magnet over the paper cup.
●
Make four sounds with frequencies
(a) 264, 396, 528, 660 Hz,
(b) 352, 440, 528, 704 Hz, and
(c) 198, 396, 495, 594 Hz.
Try to find their names of tones on a muisical scale.
Note that keyboards use slightly different frequencies.
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