1 Physics 434 Module 1, week 2 Finish (by today) the preliminary voltage-divider analysis VI. Wire up the FET current-control device

2 The FET: why do we need it? Set the voltage here… And measure the voltage and current here The IRF511 power MOSFET Transistor.

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) 3

4 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

5 Graph demo shows multiple plots

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. 6