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====User Manuals====
User Manuals
==DC Power Supply==
==DC Power Supply==
You can test the function generator by connecting it directly to the leads of an oscilloscope. Just remember that the function generator will be impedance bridged with the oscilloscope, so you may observe a slight reduction in your signal’s amplitude after connecting the function generator to your circuit. After checking your circuit, connect the leads from the function generator to the circuit before turning on the power. On our particular model of function generator, the output is always on, so keep that in mind as you use it.
You can test the function generator by connecting it directly to the leads of an oscilloscope. Just remember that the function generator will be impedance bridged with the oscilloscope, so you may observe a slight reduction in your signal’s amplitude after connecting the function generator to your circuit. After checking your circuit, connect the leads from the function generator to the circuit before turning on the power. On our particular model of function generator, the output is always on, so keep that in mind as you use it.
==Oscilloscope==
An oscilloscope is an instrument that graphically displays electrical signals and shows how those signals change over time. These electrical signals are measured with a probe that reads voltages (not current). Oscilloscopes allow you to measure things like frequency, amplitude, averages, peaks, and rise/fall times.
===Using an Oscilloscope===
The first lesson of oscilloscopes is: do not press the AUTOSET button. It is actually a mislabeled self-destruct button. This reprehensible act invokes several other abominable events… interdimensional denizens tear a gash in reality, evil spirits are summoned, and you’ll have bad luck for seven years. Few have survived long enough to pass on this wisdom. Consider yourself warned.
====User Manuals====
Seriously though, you won’t learn how to properly set triggers, display signals, or troubleshoot problems if you rely heavily on the AUTOSET button. Though the oscilloscope may look complicated, it’s not hard to understand once you get to know it. For the purposes of this certification, the AUTOSET button is off-limits, so you can save yourself the seven years’ bad luck.
One of the first things we need to understand about the oscilloscope is what it’s actually showing on the display screen. The display is set up like a standard Cartesian coordinate system (you know, a {{#evu:https://www.youtube.com/watch?v=sIlNIVXpIns|graph}}, and the units of the graph tell us a lot about what we are looking at. The y-axis is voltage, and the x-axis is time. So, an oscilloscope will show—in real time—how a voltage signal is changing over time. One key skill we need to learn when using the oscilloscope is to manipulate the scales of the x-axis and y-axis so that you can see the voltage signal clearly and meaningfully on the oscilloscope’s display.
There are 4 BNC jacks are on the bottom row of the oscilloscope’s control panel. Each one corresponds to channels 1, 2, 3, and 4. This is where you will plug in the probes that will measure various voltage signals in your circuit. Let’s discuss the knobs and buttons under the VERTICAL section of the control panel. For CH 1, the POSITION knob will move the signal on the display screen of the oscilloscope up and down the y-axis. This is handy when there is a DC voltage offset applied to the AC signal. The VOLTS/DIVISION knob will stretch or shrink the y-axis so that you can see the waveform’s amplitude properly. If the peaks or troughs of the waveform are hitting the top and/or bottom of the display screen, use the VOLTS/DIVISION knob to shrink the y-axis so that the full waveform can be seen. The CH 1 MENU button allows you to set up the probe properties and measurement displays for channel 1. The MATH MENU button allows you to perform operations between channels such as subtracting CH 2 from CH 1.
The HORIZONTAL section of the control panel let’s you manipulate the x-axis of the display screen. The POSITION knob acts as time offset. In most cases, this can be set to zero, but you’ll notice that you can shift the waveform left and right by turning this knob. The SECONDS/DIVISION knob will stretch or shrink the x-axis so that you can see the waveform’s frequency/period properly. If you’re ever wondering why your 100kHz sine wave looks like a solid fuzzy block on the display screen, you need to zoom way in with the SECONDS/DIVISION knob to see the individual peaks and troughs. You might do some basic math to know where you need to set the knob (sounds crazy, right???). 100kHz is the frequency… that means the period of the waveform is 10uS (microseconds). If I set the SECONDS/DIVISION knob to 10uS per division, then I should see roughly 5 peaks and 5 troughs of the waveform on the display screen because there are 5 dashed grid lines (4 plus the y-axis) across the screen that mark the divisions.
The trigger on an oscilloscope is an important part of properly displaying a waveform. The trigger determines when the oscilloscope starts to acquire data. When a trigger is set up properly, the oscilloscope converts unstable displays or blank screens into meaningful waveforms. Of the types of triggers available on this oscilloscope, most waveforms can be captured using the edge mode. In the TRIGGER section on the control panel of the oscilloscope, you’ll see a LEVEL knob. When you turn the LEVEL knob, you should see a little pointer moving up and down the side of the display screen (in the direction of the y-axis). Generally, the trigger level can be set to approximately the middle of the waveform for good results.
For this certification, select DC coupling from the 5 vertical buttons next to the display screen. The DC coupling option will show time-varying signals on a DC bias. The AC coupling mode will ignore any DC biases. Set both the probe and the channel to 10X attenuation.
Finally, the MEASURE and CURSOR buttons are useful for viewing the peak-to-peak voltage, period/frequency, rise/fall times, and several other measurements. The CURSOR button is used to setup the two cursors which can be used to measure and display two distinct points on the horizontal or vertical axis. The location of the cursors can be changed using the knob in the upper-left most corner of the control panel. The cursors can display useful time and amplitude values. The 5 vertical buttons can be used to alter settings for both the MEASURE and CURSOR buttons.
Practice sweet-talking your benchtop equipment; the oscilloscope’s primary love language is most certainly words of affirmation.
==Digital Multimeter==