EE188L EE I Laboratory

1
EE188L EE I Laboratory

• Lab 2Resistive Circuits

2
Objectives of Lab 2

• Understand series and parallel connections
• Understand the protoboard and Digital Multimeter
• Measure and calculate equivalent resistance
• Measure voltage difference between nodes

3
Overview of Lab 2 Activities

• Connecting 4 identical resistors together
• Putting different resistors in series
• Putting different resistors in parallel

4
Protoboard

• Good for making prototype
• circuits
• Note POWER ON button
• 3 power supplies
• 5, 15 and -15 volts
• White grid
• Holding devices
• Making connections
• Some underneath
• Some with wires

5
Simple Circuit Wiring Example
Red wire
Black wire

• Useful hints to make connections to power
  supplies
• Unscrew plastic nut of power connections
• Insert wire in hole in post and tighten nut
• Dont tighten only onto the wires insulation

6
Protoboard Power Supplies

• 3 power supplies with common ground
• Must connect between ground and one
• red terminal
• Shows maximum current available
• Do not short terminals together! Note fuse on
  side.

7
Protoboard Connections

• Connections underneath
• Long rows across the top is connected
• Each row of 5 is connected
• Each column is connected

8
Digital Multimeter DMM
Can measure voltage, current, resistance, and
diode turn-on voltage Gives digital readout
9
Measuring Resistance with the DMM
1. Red probe is in correct position 2. Make sure
the button with W is pressed 3. Place red and
black probes on two terminals when not
connected to power 4. Read value of resistance on
display and note the units
10
Measuring DC Voltage with the DMM
1. Red probe is in correct position 2. Make sure
the button with V is pressed to measure DC
voltage 3. Place red and black probes on two
nodes 4. Read value of voltage displayed and note
the units
Red probe
Black probe
Note 5.06 has 3 significant figures and 5.064 has
4 significant figures.
11
Measuring DC Current with the DMM 2
1. Connect DMM in series in the circuit 2. Red
probe is in one of current ports (100ma max or
10A max) 3. Make sure the button with A is
pressed to measure DC current 4. Read value of
current flowing into red probe on display and
note the units
12
Measuring DC Current with the DMM 1
DMM connection is tricky Open circuit and insert
DMM Reading is current flowing into red probe
13
Resistor Color Code
56 10 kW 560 kW
237 1 W 237 W
http//www.elexp.com/t_resist.htm