Tools of the Trade Pt. 2

Intro

So far, we’ve used multimeters to determine voltage. Yet, they take a moment to read even static, unchanging voltages. This week, we’ve also started to investigate voltages varying over time, as is the case with sounds like music. Even if it could update instantly, the human hear can perceive sounds up to 20,000Hz, while the human eye can’t feasibly see changes above 60Hz, so we’re somewhat out of luck. Enter the Oscilloscope.

Connections

In the back of the room, there’s three hanging cables you should grab.

• Yellow probe
• Green probe
• Power cable

These will connect to their similarily colored terminals on the “o-scope”

Powering a circuit (DC)

Nicer (read: more expensive) oscilloscopes are capable of powering circuits in various ways. For this lab, we’ll use two of them. First, connect the two terminals of the power cable to the power rails on your breadboard. From there, turn on the oscilloscope, press the black “Default Setup” button, and once it has finished, hit “Wave Gen” in the bottom right (it should glow blue). From there, you’ll need to hit some settings, ask your counselor for help if you need.

• Waveform: DC
• Offset: 6V

Probing the circuit

Grab the channel 1 probe (yellow), connecting it to the positive and negative terminals with the hook and alligator clip, respectively. Make sure channel 1 is enabled (hit the 1 button if not); it should be glowing yellow. With some amount of luck, you should see a horizontal line across your screen. Pay special attention to the scale in the upper left corner of the screen, which reveals the vertical access (volts), along with the number towards the center, which is a time scale. You may need to adjust these values using the horizontal and vertical knobs.

Now, hit wave gen until it stops glowing (now it’s no longer providing power), create a voltage divider