Transcript Document
EE188L EE I Laboratory Lab #2 Resistive 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 Red wire +5 V 1 k 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 +5V at 1.0 AMP 3 power supplies with common ground • Must connect between ground and one red terminal • Shows maximum current available +5 V Do not short terminals together! Note fuse on side. +15V at 0.5 AMP +15 V -15V at 0.5 AMP -15 V Protoboard Connections Connections underneath: •Long rows across the top is connected •Each row of 5 is connected •Each column is connected Digital Multimeter = DMM Can measure voltage, current, resistance, and diode turn-on voltage Gives digital readout Measuring Resistance with the DMM 1. Red probe is in correct position 2. Make sure the button with 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 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 + 5.06 V - 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 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 DMM I I 5V Resistor Network Measuring DC Current with the DMM 1 DMM connection is tricky Open circuit and insert DMM Reading is current flowing into red probe DMM I I 5V Resistor Network Resistor Color Code 56 * 10 k = 560 k 237 * 1 = 237 http://www.elexp.com/t_resist.htm