Week One Blog

Monday:

The lab is formatted so that every week begins with a pre-quiz. After the pre-quiz is completed there is to be a quick lab introduction to introduce ideas to know for the following week. The remaining time involves students completing said lab. Students discuss blog entries on Friday and end the week with a post quiz.

The important safety tips for the classroom are:

• Fire Extinguisher is located in the corner of the room by the right door.
• First Aid kit is located by the left exit door, behind the podium.
• The telephone in the classroom is located on the podium.
• If there is an emergency call 911.
• If equipment seems defective, let the instructor know before continuing use if deemed safe.
• Keep all work areas clean and clear of all unnecessary parts.
• Make sure power is off when working on circuits.
• Always ground your circuit properly.
• Do not attempt to work on a circuit with wet hands.

These safety tips are very important because current can kill you if it exceeds 100 mA.


Reading resistors is a simple task as long as you know the process used to read them. Below is a video explaining how to read both five band resistors and four band resistors.

The tolerance of a resistor is the determined range of error between the resistance value printed on the resistor and the actual resistance value. For example, none of these resistors have the exact resistance value that is printed, but they are all within the tolerance.

Wednesday:

When measuring current using a DMM you have to break the loop to get the current to flow through the DMM. If not, the current will remain in the circuit because that path is easier to take. With measuring voltage, the loop must remain intact to allow a current to flow. If the circuit is broken, no current will flow causing there to be no voltage. 

At any given time you can have three different voltages being supplied by the power supply. One is fixed at 5V while the other two can vary from 0V to 25V.

5.04V 47.7mA

Measuring Voltage with a handheld Digital Multi Meter. When measuring voltage, the circuit must create an independent loop in order for the voltage to be anything but zero.

Measuring Current with a handheld Digital Multi Meter. When measuring current, the circuit must be broken before the reading is taken otherwise the measured value will be zero.

Ohm's Law states that V=I*R or Voltage = Current * Resistor, and can be proven by measuring the current through the same resistor using multiple voltages. These two values can be plotted on a graph to show a linear correlation between them. The slope of the resultant line is the value of the resistor.

Here is an experiment proving Ohm's Law with two different resistors:

Below is our first Rube Goldberg circuit using a photo-resistor and DC Motor.

Friday:

This is the circuit diagram for the above Rube Goldberg design.

This circuit can be used for different types of mechanical functions. We decided to make a quick Rube Golberg design in which a flashlight is used to make the motor/fan spin at a faster rate. The fast spinning motor is attached to a string, which will lift a door and the marble will begin to move downwards on a ramp. At the bottom of the ramp is a basket sitting on a pressure sensor. When the marble lands in the basket, the pressure sensor will engage and allow power to flow to a fan, which will keep us all cool!