FACET
HELP
For the Model 1250-10
VIRTUAL INSTRUMENT
Used with Tech-Lab or Mind-Sight
This document will help the user perform the ADD, INVERT functions
using the Virtual Instrument Model 1250-10.
To demonstrate this procedure we will use the AC 1 Fundamentals
Curriculum in Tech-Lab. The content is the same in Mind-Sight.
We will use lesson:
AC MEASUREMENTS
Exercise Procedure
Ex. 2 Measuring With an Oscilloscope
The screen below has the student prepare the Facet board.
This screen they will locate the circuit and install two post connectors where
needed to complete the circuit. Also connect the Generator leads at this time.
After step 2, launch the TiePie Virtual Instrument software in order to adjust
the settings.
Your screen should look like the one below.
Next adjust the probe settings for Ch 1, and Ch 2 by right clicking on each in
the tree on the left under Instruments, then slide down to Probe settings and
left click, then down to 10x and left click. Do the same for Ch 2.
Next, double click on the function generator symbol in the tree. It will open
with a default frequency of 1kHz sine wave which we will use. Next, adjust
the 10Vpk-pk sine wave by using the slider and arrows under amplitude for
5V which will give a 10Vpk-pk signal. Left click on the output button and
minimize the window.
Follow step 3, and remember to remove the two post connector across R2.
Next, left click on the letter A below to bring the signal in view on Ch 1.
Next, right click in the viewing screen and select show cursors to measure
the voltage.
Read the voltage under Ch 1 column and across from the Top-Bottom
heading. Use this value to calculate the current in step 3 above. The answer
here should be in the range of .22 volts. Your calculated value for step 3
above should be in the range of 22 mA.
Follow step 4 below to measure the voltage across R1.
Follow step 5 below and check probe settings, and be sure to reinstall the
two post connector across R2.
Left click on the letter A, and your screen should look like the one below.
Next, we will INVERT Ch 2 by right clicking on I/O’s in the tree, slide
down to Gain/Offset and left click. This will be put it in the tree.
Now right click on it, left click on Gain, and slide down and left click on -1
on the extended menu. A Gain of -1 will INVERT any signal.
Next, click and hold on Ch 2 drag it down and drop it on Gain/Offset. In
order to see it on the screen left click and hold, drag it into the screen and
drop.
Your screen should look like the one below. The light blue trace is Ch 2 and
the violet trace is it INVERTED.
Next we will add the INVERTED Ch 2 to Ch 1. First right click on I/O’s in
the tree then slide down and left click on Sum. This will put Sum in the tree.
Next left click and hold Ch 1 and drag and drop it on the Sum. Next left
click and hold on Gain/Offset and drag and drop it on the Sum.
Next left click and hold on the Sum and drag and drop it into the screen.
Your screen should look like the one below. The dark blue trace is the sum
of Ch 1 and Ch 2.
To measure the voltage of R1, right click on the screen and slide down to
show cursors. In the Sum 1 column come read down to and across from TopBottom. This voltage is the fill-in answer for step six below.
The answer is in the range of 8.2 Volts. See below.
This step the board is cleaned up for the next student.