ee188l ee i laboratory lab #2 resistive circuits
TRANSCRIPT
EE188L EE I Laboratory
Lab #2Resistive Circuits
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
Overview of Lab #2 Activities
Connecting 4 identical resistors together
Putting different resistors in series
Putting different resistors in parallel
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
Simple Circuit Wiring Example
+5 V 1 k
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 Don’t tighten only onto the wire’s insulation
Protoboard Power Supplies
+5 V +15 V -15 V
+5V at1.0 AMP
+15V at0.5 AMP
-15V at0.5 AMP
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.
Protoboard Connections
Connections underneath:
•Long rows across the top is connected
•Each row of 5 is connected
•Each column is connected
Digital Multimeter = DMMCan measure voltage, current, resistance, and diode turn-on voltage
Gives digital readout
Measuring Resistance with the DMM
1. Red probe is in correct position2. Make sure the button with is pressed3. Place red and black probes on two terminals when not connected to power4. Read value of resistance on display and note the units
Measuring DC Voltage with the DMM
1. Red probe is in correct position2. Make sure the button with V= is pressed to measure DC voltage3. Place red and black probes on two nodes4. Read value of voltage displayed and note the units
+ 5.06 V -Red probe Black probe
Note 5.06 has 3 significant figures and 5.064 has 4 significant figures.
Measuring DC Current with the DMM 2
1. Connect DMM in series in the circuit2. 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 current4. Read value of current flowing into red probe on display and note the units
5 VResistorNetwork
DMM
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Measuring DC Current with the DMM 1
DMM connection is trickyOpen circuit and insert DMMReading is current flowing into red probe
5 VResistorNetwork
DMM
I
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Resistor Color Code
http://www.elexp.com/t_resist.htm
56 * 10 k = 560 k
237 * 1 = 237