Transcript ppt

Physics 434 Module 1, week 2
• Finish (by today) the preliminary voltage-divider
analysis VI.
• Wire up the FET current-control device
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The FET: why do we need it?
The IRF511 power
MOSFET Transistor.
Set the
voltage
here…
G
D
S
And
measure the
voltage and
current here
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Requirements for your VI
• Data:
– current and voltage vs. applied voltage. (Nearly identical to the plot
you made for the simple divider)
– A hint: do not assume the “22” resistor really is!
• Analysis:
– Resistance vs. current for the bulb
• Comments:
– Beware that you will need to introduce a delay from changing the
current to measuring the resulting voltage and current. Think about
how to decide how much you need
– The current setting of the DC voltage VI is for -10 to +10 volts: you
get more accuracy if you reduce it to the range that you really need.
(If you do so, this should be mentioned in your documentation)
– The ACDs are by default -10 to 10; change to 0 to 5 (factor of 4
more accurate)
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Use vi libraries (llb files)
• Get from tools | LLB manager
– Use New to make a new llb file
• Advantages
– Behaves like a folder (in
Windows at least): drag/drop
double-click to open …
– SubVI’s are automatically
found
– Must use to submit
multiple VI’s to catalyst
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Graph demo shows multiple plots
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Turning in your VI(s)
• Edit | Make current values default – needed to record
your results
• File | VI properties | Documentation:
write a little report, containing your name(s), purpose
of the VI, implementation features, conclusions.
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