Question about Oscilloscope manual.

Thread Starter

hitmen

Joined Sep 21, 2008
161
This is not exactly a qns but a request.

Does anyone know where I can retrieve laboratory equipment manuals?

Description Model
KENWOOD osciloscope CS-5355
ESCORT function generator EGC-3230
FLUKE Digital Multimeter FLUKE 45
TOPWARD DC power supply TPS6303

Also what does the VARIABLE control knob in an osciloscope do? I only know that we are supposed to rotate it to the end during a lab session.:confused:
 
Last edited:

KMoffett

Joined Dec 19, 2007
2,918
Also what does the VARIABLE control knob in an osciloscope do? I only know that we are supposed to rotate it to the end during a lab session.
Missed that. The Variable knob, if it's in the vertical input section, allows you the vary the amplification of the input. Normally there's a CAL position on the knob that sets the amplification to exactly so many volts or millivolts per major screen division. The Variable control lets you scale the screen to something that's more usable for your viewing or measurement.

Ken
 

KMoffett

Joined Dec 19, 2007
2,918
In that case, wouldnt the VARIABLE knob affect one's reading?
Yes, it would affect the amplitude readings. But, a scope is mostly used for looking at other things than absolute amplitude accuracy. If you wanted to compare the phase difference of two different signals, it's a little easier if they appear the same size on the screen, even if their actual amplitudes are greatly different. Also, if you are looking for small anomalies in a signal you may want to make the signal as large as possible on the screen. The Gain switch steps (1, 5, 10....) may made it too large on one step and too small on on the next. The Variable control lets you make these small amplitude adjustments between gain steps for better visualization. This also applies to the Variable on the horizontal sweep.

Ken
 

Thread Starter

hitmen

Joined Sep 21, 2008
161
Thanks. I see. If one accidently adjusts the variable knob, is there any way to tune it back to the original condition. Thanks.
 

KMoffett

Joined Dec 19, 2007
2,918
The "Variable" knobs usually have a "CAL" position, for "calibrated", at one extreme of rotation, either CW or CCW. If the knob is rotated back to that position the display will be calibrated to X divisions per X volts.

Ken
 
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