Introduction.
This assignment will allow further investigation of filter characteristics and introduce the use of commercial filter modules. We will use the Burr-Brown UAF42 2-pole universal filter.
Download and save filter2.ewb and filterstate.ewb.
The circuit in filter2.ewb is a VCVS
filter. The circuit in filterstate.ewb
is a state-variable filter based on the UAF42. When you simulate these filter
circuits, remember that Electronics Workbench only updates the Bode Plotter
when you switch on the power, and not when you change a switch or potentionmeter
in the circuit.
You will be using Burr-Brown design software which has been loaded on the lab
computers. You can download it to your own computer by going the the Burr-Brown
site and searching for "filterpro". A demo of the software will
be given in lab. The DOS-compatible program FILTER42 guides you through the
design process and automatically calculates component values. Low-pass, high-pass,
band-pass, and band-reject (or notch) filters can be designed. Download the zip file containing the FILTER42 software by choosing Open with CompressedFolder, then double-click filter42.exe, and click Run.
Note that in this and every lab assignment the verb build means to construct a circuit on the protoype board whith actual parts. The verb simulate means use Electronics Workbench mathematically simulate the circuit.
filter2.ewb. Vary the resistor Rf
to optimize pulse response and separately to optimize the steepness of the
cutoff region. Record the value of Rf for each condition and relate the
values to the values calculated for Bessel and Tchebychev filters.Your lab notes should include the results of the simulations and schematic of the actual circuits you built.