ENGR 16
Lab #3
Names:__________________
__________________
AC Voltages and Superposition
Part A Fill in the equivalent values (assume sinusoidal).
Period
_____
1 ms
_____
Frequency (Hz)
60 Hz
_____
_____
Peak
_____
_____
1.2 vp
Peak-Peak
_____
22 vp-p
_____
Frequency (rad/sec)
_____
_____
53820 rad/sec
RMS
115 vrms
_____
_____
Compute the equation (and other information) for the following curves.
Period (sec)
Frequency (Hz)
Frequency (Rad/sec)
Amplitude (Peak)
DC Offset (Average)
RMS Voltage
Phase Shift
_____
_____
_____
_____
_____
_____
_-90°_
Equation (use cosine)
_________________
volts
t (s)
volts
Period (sec)
Frequency (Hz)
Frequency (Rad/sec)
Amplitude (Peak)
DC Offset (Average)
Equation
_____
_____
_____
_____
_____
_______________________
t (ms)
ENGR 16
Lab #3 (Cont.)
Names:____________
_____________
Draw a sketch of the following two voltages.
A) -3+4cos(6283t) volts.
B) 2 volt peak-peak cosine @
500 Hz, with a 2 volt DC offset.
Compute the RMS values for the following voltages (show your work).
A) -3+4cos(6283t) volts.
B)
volts
t (ms)
ENGR 16
Lab #3 (Cont.)
Names:____________
____________
Part B Calculate the voltage across R2 by using a single node equation. Vsig will need to be
written in its full cosine format. Your calculator can then compute the voltage across R2. It will
have both a DC component and an AC (cosine) component added together. Show your node
equation and record your calculated result:
Node equation:
VR2(t):
Part C Draw the two simpler circuits that supress each voltage source (one at a time.) Use the
voltage divider equation to compute the AC and DC voltage components across R2. Show your
work and your results.
VR2(t):________________________
ENGR 16
Lab #3 (Cont.)
Names:____________
____________
Part D Build the circuit in MultiSim. There are three different options for generating the AC
input: AC signal voltage source, AC power source, or Function generator. Each has different
ways of representing the cosine voltage (peak/amplitude or RMS). Start with the AC signal
voltage source. ALWAYS include complete units (Vrms, Vpeak, VDC, Vp-p) on all shortcut
representations. When written as a funtion of time (with the cosine) the units will just be volts.
AC signal peak setting:___________
AC signal frequency setting:___________
AC meter reading for VR2:___________
DC meter reading for VR2:___________
Convert VR2 readings into a function of time:_____________
Replace the AC signal voltage source with an AC power source. Adjust the setting so the
source inputs the identical sinusoidal voltage. The R2 voltage should match as before.
AC power source setting:___________
Replace the AC power source with a function generator (pulled from the icons on the left). The
function generator has three connections + com –. “com” is our ground, common to all the
signals. We won’t use the – connection (this is used when you want both a sinusoid and it’s
inverted “opposite”.)
Function generator settings:___________