Test 1

Monday - Bring:

  • Calculator
  • Writing instruments
  • Page of notes

Test resubmissions

If you are dissatisfied with how you did on several (or more) of the exam problems, you may resubmit:

  • Whether you scored high or low on the in class exam, or on the resubmission... It always makes a good impression on me when you re-submit. I think: "Wow, here's a person who is not just giving up, but is willing to work to figure out what they didn't quite get the first time!"
  • Get a copy of the test from Paul,
  • Turn in your resubmitted exam at (or before) the beginning of class on Friday morning.

  • You do not need to resubmit the whole exam. You may resubmit just a few problems.
  • You may consult our class notes, internet resources, textbooks, even other people.
  • No credit will be given if you just write down the correct answer. To receive credit you must include supporting work: Show how you calculated, or what steps you went through to get to your answer; Explain why you placed a piece of code where you did in the skeleton;
  • For each resubmitted problem, I'll replace your in-class score with the average of your in-class exam and your after-class resubmission.

Review / Guide

This is not exhaustive, but is meant to list some of the main content you should know and be able to use to solve problems:

Ohm's Law / Kirchoff

Solving problems / circuits

  • $V=IR$
  • At any point $\sum I_\text{in}=\sum I_\text{out}$.
  • Voltage drops from a starting point to an ending point are the same for any connecting path.
  • Ideal wire: 0 resistance / voltage is the same throughout any wire-only segment.
  • Resistances in series and in parallel

Thevenin equivalent circuit

Any network of resistors, batteries, (voltage signals), current sources has a behavior at its output which is indistinguishable from that of a single (ideal) voltage source, $V_\text{th}$ in series with a single (internal) resistor, $R_\text{th}$.

  • $V_\text{th}$ is Voltage at the outputs with no load.
  • To find $R_\text{th}$: Replace Battery$\to$wire and current source$\to$circuit break, then evaluate resistance across outputs.
  • If load = $R_\text{th}$ then $V_\text{out}=\frac 12 V_\text{in}$.

Voltage dividers & loading

  • typical circuit: voltage divider with load across in parallel with "bottom" resistor.
  • 10:1 rule.
  • Voltage drops of Thev. device depending on load.

C programming

  • comments
  • syntax
  • case sensitivity
  • code blocks between ${...}$
  • "Typing" (declaring) variables and initializing them.
  • Global vs local variables
  • if( ){...} else { ... } program control
  • Looping with for( ){...} and while( ){...}, and break;
  • Arduino code structure
  • Functions for raising and lowering pin values, modifying pulse widths.

Pulse Width Modulation

  • Going back and forth between frequency and period via $f=1/\tau$
  • Reading period, amplitude, p-to-p voltage off oscilloscope traces
  • Duty cycle

Dealing with units

  • mA, V, mV, $\Omega$, K$\Omega$.
  • seconds, milliseconds, microseconds
  • Hz = cycles (or 'periods') per second, kHz, Mhz