E-3 Meters And Test Equipment Flashcards
Oscilloscopes show :
Waveform , Time , Peak to Peak voltage , Phase Relationship
Construction of a Oscilloscope :
Electron gun , horizontal + vertical deflection plates , fluorescent screen
What does the Electron Gun do ?
Emits beam of electrons . Beam travels through deflection plates to the screen .
What results because of “ too strong a beam “
The phosphur burns a hole into the fluorescent screen
Too much Intensity
Why is Trace observed on the Oscilloscope screen ?
Electrons are striking the screen , Location of the wave is determined by the voltages on the deflection plates .
How is Saw tooth Voltage produced ?
Made by the Internal Sweep Generator
What is the Grid System called?
Graticule
What does Voltage control in the Oscilloscope ?
vertical deflection plate
What does Frequency control in the oscilloscope?
horizontal deflection plate
Saw tooth Voltage is triggered by :
Internal Sweep Generator / Vertical Signal
Magnitude of Voltage in an Electron gun can be :
1000 v - 25 000v
What does Intensity Control do ?
Allows Adjustment of Trace Brightness ( Bright to Dim)
What plays a factor in producing Saw tooth ?
Triggered by voltage input on vertical plates
What is the function of the Vertical Rotary Switch ( volts / div )
Increase + Decrease number of volts per block on screen
DC - GND - AC <——-
All Dc signals are blocked , AC Signals appear on screen
What is meant by the term “direct coupling” ?
All components of the vertical input signal appear on the screen
GND means ground, ground :
Shows where the zero level is located, helps center the trace
What does focus control do ?
Allows adjustment of Trace thickness + definition (less fuzzy)
Amplitude is a measure of :
Peak to Peak
Rms value is
.707
average value of a sine wave is
0
Average value is
.637
How do you find voltage values?
Count the blocks up the y+ x the volts/div dial x the probe X1 is 1 X10 is 10.
Thus 2.4 x .5mv x 10 =
How do you calculate time or frequency values?
Count the number of blocks for the entire wave (starting point to where it starts repeating), use the time/div dial .2ms/cm.
8 1/3 cm x .2ms/cm=
Or T=1/F
Or F=1/T
