THURRRRSDAY

Thursday is today is thursday is today.  We have begun studying starter motors today (time goes so fast!) and Hans pulled apart a starter motor and showed us how it works.  Inside the starter motor is quite simple.  A high resistance solenoid is connected to a large electric motor that has a pinion gear to rotate the fly wheel.  Quite interesting.  I can roughly explain how a starter motor works.  the solenoid and motor is connected to the battery directly and the circuit is opened and closed via another terminal that works similar to a relay.  When the key is turned to start,  the circuit closes and power is provided to the starter motor.  When the solenoid kicks in,  it moves the starter motor itself, which is called the armature,  and the armature moves forward connecting the pinion gear to the flywheel.  The pinion gear is very small compared to the flywheel (or flexi-plate, automatic!) giving it very high torque, which obviously is what it needs to crank an engine.

The point where I was beginning to get very confused was when we began taking the exercises on testing the starter motor.   We were told to unplug either the spark plugs or the fuel rail, to stop the engine starting.   The exercise involved testing available voltage, voltage drops, in between everywhere in the circuit.  Hans explained how it is important where you point the multi-meter pins, as power is lost through the cables. I didn't know that until today!  Things begun to clear up slightly, when we were in the lecture room discussing the diagrams of the circuit of the starter motor.  But before it came completely clear to me,  Hans handed out exemplars of our assessment, which will be taken on Tuesday! I was slightly in shock.  Hans wanted us to write down the questions we didn't understand, so I did.  I ended up writing down quite a lot of questions.  There were words in there that I was not familiar with.

Must get to writing topics (alternators and starter motors) I am falling behind.