Basic Waveforms and Oscilloscope Operation ECE 2100 Circuit Analysis updated 7 S
ID: 2293746 • Letter: B
Question
Basic Waveforms and Oscilloscope Operation ECE 2100 Circuit Analysis updated 7 September 2016 Pre-Laboratory Assignment 1. Go to the website http:llwww.tek.com/education/oscilloscopes/reference_materials.html and download the XYZs of Oscilloscopes by Tektronix. Read (page numbers as in the document, not as listed by the pdf viewing program): "The Oscilloscope" section pages 7-12 and "The Systems and Controls of an Oscilloscope" section pages 19-33. 2. In one paragraph (use proper English): what is the basic purpose of an oscilloscope? 3. In one paragraph (use proper English): what is the difference between AC and DC coupling? 4. In one paragraph (use proper English): what is the purpose of the trigger system?Explanation / Answer
2. The oscilloscope is basically a graph-displaying device – it draws a graph of an electrical signal. In most applications, the graph shows how signals change over time: the vertical (Y) axis represents voltage and the horizontal (X) axis represents time. The intensity or brightness of the display is sometimes called the Z axis. An oscilloscope is a laboratory instrument commonly used to display and analyze the waveform of electronic signals. In effect, the device draws a graph of the instantaneous signal voltage as a function of time.
3. Coupling refers to the method used to connect an electrical signal from one circuit to another. The coupling can be set to DC, AC, or ground.
The AC coupling setting is useful when the entire signal (alternating current + direct current) is too large for the volts/
div setting. The ground setting disconnects the input signal from the vertical system, which lets you see where zero volts is located on the screen. With grounded input coupling and auto trigger mode, you see a horizontal line on the screen that represents zero volts. Switching from DC to ground and back again is a handy way of measuring signal voltage levels with respect to ground.
4. An oscilloscope’s trigger function synchronizes the horizontal sweep at the correct point of the signal, essential for clear signal characterization. Trigger controls allow you to stabilize repetitive waveforms and capture single-shot waveforms. The trigger makes repetitive waveforms appear static on the oscilloscope display by repeatedly displaying the same portion of the input signal.