During this lab course, you will explore the behaviour of discrete electrical components such as resistors, capacitors, diodes and transistors as well as digital and analog integrated circuits. Over several lab sessions, the various functional blocks of a mystery circuit will be analysed to suggest a hypothetical model for their behaviour. The experimental results will then be compared with those predicted by the theory.

A central component of this laboratory experience will require the student to become familiar with the operation of some instruments used to make a meaningful analysis of electronic circuits. Among these are the multimeter, used to measure voltage, resistance and current, and the waveform generator, used to inject a signal of varying voltage into a circuit being analysed.
The oscilloscope provides a convenient way to visualise and measure how the amplitude of one or more voltages changes as a function of time as well as how these voltages change relative to one another.

Your ability to use these analysis tools will be tested at the end of the term as part of a lab exam where you will be required to determine the function of some voltage divider circuits by measuring their component values and by analysing their response to various input signals.

The multimeter

The multimeter (MM) allows you to measure direct (DC) and alternating (AC) voltages and currents as well as the resistance of electrical components. It will measure resistances much more precisely than the Component Tester (CT), generally to 0.004% or +/- one least significant digit of the displayed value. Note that this resolution will expose variations in the measured quantity due to temperature changes as well as incorrect results due to poor circuit assembly technique.

The oscilloscope

An oscilloscope displays on a two-dimensional grid the variation in voltage (y) with time (x) of one or more input signals. A digital scope includes a lot of features intended to make the measurement and analysis of these signals easy. The basic controls of the two-channel Instek scope are grouped into the following functional blocks:

1. the VERTICAL controls set the voltage gain and input coupling for each channel. Select a channel by pressing the CH1 or CH2 keys, then use the VOLTS/DIV knob to adjust the vertical resolution, or gain, of the waveform. The voltage gain per grid division is shown on the bottom of the display. You can use the grid to make approximate measurements or preferably, use the framing cursors.

   Press the CURSOR button, followed by the X-Y button to display two horizontal cursors in the same colour as the selected channel. Select a cursor Y1 or Y2 and position it with the VARIABLE knob; their values and difference Y1Y2 are shown to the right.

   The coupling selection allows the input channel to be grounded (displaying a flat line at V=0), to view the input signal as it is (DC) or view it with the DC component removed (AC). The AC setting can be used to focus on a small varying signal when it is offset by a larger DC voltage.

2. the HORIZONTAL controls similarly set and adjust the common time scale for the two input channels. Again, you can use the cursors to take measurements.

   With the XY mode selected, CH2 (y) is displayed as a function of CH1 (x), typically generating a Lissajous curve that provides an alternate way to view and measure the frequency/phase/amplitude relationship between two signals.

3. the TRIGGER controls synchronize the horizontal sweep of the scope to a set position (level) and direction (slope) of a signal, to stabilize repetitive waveforms and capture single events. This trigger point is identified by the down arrow located at the top of the display grid.

   The sync voltage level is set with the LEVEL knob and is monitored by the arrow on the right edge of the display. Press the MENU button to access the trigger options.

   The slope button in the Slope/Coupling submenu selects whether to sync to the ↑ (positive) slope or the ↓ (negative) slope of the waveform at the set sync voltage. The trigger source can be either CH1, CH2, the 60Hz Line input to the scope, or some External input connected to the EXT TRIG connector.

   The SINGLE capture mode causes the scope to wait for a trigger event, record a single screen and then stop; this is useful when monitoring non-periodic events.

4. The CURSOR button toggles the display of two horizontal or vertical cursors that can be used to measure waveform time/voltage values and their differences. Their position is adjusted with the VARIABLE knob.

Note that there are, horizontally and vertically, 25 cursor steps per grid division. Hence the cursors resolution is 1/25 of a grid division and the voltage or time measurement error is always ±0.02 of the VOLTS/DIV or the TIME/DIV setting.

The lab sessions

Your Electronics explorations will not be documented as weekly lab reports; rather we will use a lab-book format where pertinent results are accumulated and recorded in real-time as done in a research lab, where the investigator has an intimate understanding of the theory and steps to be performed, well before any data is acquired to test the validity of some prediction.

A successful lab experience will thus rely heavily on the student having read the lab manual to become familiar with the tasks to be performed and the equations used to predict/validate experimental results.

This pre-lab work outlines a plan of action to follow and might include some empty data tables and reminders to include a graph, calculation or other relevant item.

Being so prepared, the lab session will consist mainly of acquiring a series of measurements and entering these into the "lab book", along with graphs and calculations. The lab book is also an archive for documenting specific issues, problems and insights relevant to the experiment. The lab book entry will be due at the completion of the lab session.

The lab instructor is available to inform and assist the students with the operation of the instruments and to help troubleshoot issues that may arise; the lab instructor will not review details that are clearly stated in the online lab manual or provide answers to 'what do I do next?" kinds of questions.

The lab book

Use a text editor that can export the document as a 'pdf' encoded file. To make efficient use of your lab time, always record your results directly into the file rather than a piece of paper since these would then need to be copied to your computer, with the possible introduction of errors.

You should also know how to take a picture with your smart phone and import it to the document, using your Brock email for the transfer or by connecting your phone directly to the workstation as a USB drive. In the latter case, a proprietary cable may be required.