# Week 3

Another content-packed week. We looked at Ohm’s Law in more depth, and looked at series, parallel and combination resistance circuits as well as touching on capacitors and inductors. Other than the inductors it was nothing I hadn’t previously covered in year 10-12 physics and I was moderately surprised at how much of it I remembered.

Then, about mid-week, we entered the first area which was completely new to me… Being able to calculate the resistivity of a material from its physical properties (length, cross-sectional area, type of material, etc), and how it deals with changes in temperature. We also learned to calculate the time a capacitor takes to charge, and what happens to the voltage (in DC) as it charges. We didn’t really cover discharge rates.

We got our first taste of practical work this week. We spent some time in the workshop bending PVC conduit using an LPG burner to heat it, and also using a bending spring (a simple device which, as the name suggests, is simply a long spring which is inserted into the conduit to retain structural integrity while you bend the conduit over your knee). Sharper angles are possible with the spring (but not more than 90 degrees or you’ll never get the cable through!), and it is quicker than the burner, but I found it much more difficult to use. Like anything, though, practice makes perfect, so I’ll probably invest in a spring and some conduit to practice with at home.

On Wednesday afternoon we measured several resistances and capacitors in various configurations using a DMM (Digital Multi Meter) and a Megger to test the validity of the theory that we have been learning so far.

My more astute readers will probably notice that my descriptions of what we are doing are becoming gradually more specific as time goes on. As this course progresses, it has been brought to my attention that throughout my apprenticeship I will be required to keep a log of all work I have performed. This has, in turn, lead to an improvement in the way I take notes during class time and I figure I should get into the habit of chronicling my prac work as well. Plus, I’ll be able to use the notes I make here as the basis for my resume when looking for work.

Speaking of which, we have yet to be told exactly when we are to start our five week work placement, which makes it difficult to arrange somewhere to work. If I am asking someone to take me on for five weeks, I figure the least I can do is let them know when I’ll be working with them!