ME 445 – H03
Name _________________________
1) Use complex numbers to plot gain G and phase  as a function of frequency f for the firstorder low-pass RC filter shown below. Plot log10(G) versus log10(f) from 1 Hz to 1 Mhz. Plot 
in degrees versus log10(f) over the same range. Attach hard copy of your code.
V in
V out
R = 10 K
C = 1 F
R
C
G = Vout / Vin
2) Write simple equations for VA / VS and for VB / VS in the strain gauge half-bridge shown
below using variables R and R. Then write an equation for Vout / VS using the same variables.
VA / VS _______________
VB / VS _______________
Vout / VS _______________
b) Determine differential voltage Vout if the strain gauges are attached to a cantilever aluminum
beam with  = 2000 inch/inch strain at both gauge locations as shown below.
Vout _______________
c) Describe two reasons why you should use an instrumentation amplifier to measure Vout with
an Arduino analog input.
______________________________________________________________________________
______________________________________________________________________________
VS
R
R-R compression
VB
VA
VOUT = VB – VA
R
R+R tension
bridge specifications
VS = +5 VDC
R = 1000 
R / R =   for  = 2