Tracker-2800-2800S.pdf - 第38页
38 Now that you have an idea of what the signatures of different resistor value s look like in different ranges, the next part will give you an idea of what happens when you var y R S source resistance, V S source voltag…
37
To display the analog signature of a resistor:
1. Select the Tracker tab of the Signature pane of the Huntron Workstation Software.
2. Select the 50 ohm range by clicking the Resistance dropdown button and selecting 50.
3. Place or clip a test lead on the opposite ends of a resistor and observe the signature.
Below are four analog signatures of different resistors, 150, 1.5 k, 15 k and 150 k ohms in each of the
four Ranges. Note how the slope or angle of each analog signature changes with each resistor's value.
100 1 k 10 k 100 k
Vs=20V, Rs=100kFs=200Hz
100 1 k 10 k 100 k
Vs=20V, Rs=10k Fs=200Hz
100 1 k 10 k 100 k
Vs=15V, Rs=1k Fs=200Hz
100 1 k 10 k 100 k
Vs=10V, Rs=10 Fs=200Hz
Figure 3-2. Signatures of Different Resistors in 4 Ranges.
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Now that you have an idea of what the signatures of different resistor values look like in different
ranges, the next part will give you an idea of what happens when you vary R
S
source resistance, V
S
source voltage and F
S
source frequency of the Tracker 2800 and how it affects the resistive analog
signature.
The Effect of R
S
on Resistor Analog Signatures.
Select the 10V, 50 and 200Hz. Change the resistance range to 200, 1K and 5K.
Observe the signatures for a 100 ohm resistor in the figure below as R
S
varies. Note how these resistor
signatures respond to changing Tracker 2800's internal resistance.
R
S
= 50 R
S
= 100 R
S
= 1K R
S
= 10K
Figure 3-3. Effect of Varying R
S
on a 100Resistor Signature
The Effect of V
S
on Resistor Analog Signatures.
Select the 10V, 50 and 200Hz. Change the voltage range to 5V, 2V and 200mV.
V
S
= 10V V
S
= 5V V
S
= 2V V
S
= 500mV
Figure 3-4. Effect of Varying V
S
on a 100 Resistor Signature.
Observe that these signatures do not change with the changing voltage. Note that Vs cannot be set
above 10V because R
S
is set to a value of 50 . This limit on range parameter combinations is a result
of the Tracker 2800's STAR feature. It protects components from possible excessive power levels. In
order to set V
S
to a higher voltage, you must change R
S
to a higher value first.
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The Effect of F
S
on Resistor Analog Signatures.
Select the 10V, 50 and 20Hz range. Change the Frequency to 60Hz, 1KHz and 2KHz. Observe the
resistor signatures in the following figures do not change as F
S
changes.
Fs = 20 Hz Fs = 60 Hz Fs = 1KHz Fs = 2KHz
Figure 3-5. Effect of Varying F
S
on a 100Resistor Signature.
Shorts, Opens and Resistor Faults
Two of the most common faults that occur in electronic components and circuits are shorts and opens.
A short circuit is typically a 0 to 10 low resistive path between two points in a component or
circuit that normally would have a higher resistance between them. An open circuit is a break between
two points in a component or circuit that prevents current from flowing.
Short Open
Figure 3-6. Short and Open Signature.