EGR 224/Active Filter

The following page provides some supplemental information for the Active Filters lab for EGR 119L. It has been updated to Spring, 2009.

Points of Clarification

• 8.4.2 - be sure to complete the wiring in Tables 5.1-5.4 EXCEPT for the wires that go into DAC0OUT, DAC1OUT, and AOGND. Repeat - do NOT install the red wires for DAC0OUT, DAC1OUT, or AOGND. If you are using more than one red wire, you have done something wrong! Installing these wires will short out your audio source and you will not be able to get sufficient volume.
• In all cases, make sure the breadboard is turned on and the voltages are turned fully on before taking your data. The danger here is that the original sound c1 will sound OK even if the power is off since it does not pass through any op-amps. The important data - c4 - will be wrong, however, unless the op-amps are powered.

Images

Wiring

Closeup of the LM 342 with buffer wiring and OpAmp 1 copy wiring

Closeup of the LM 342 with buffer wiring and OpAmp 1 copy wiring; includes four measurement wires (dark green) - reference voltages for these wires in the top blue row and connected to ground

Oscilloscope

Oscilloscope showing four measurement channels with Channel 0 measuring a signal with an approximate maximum amplitude of 1 V

Click on the pictures at right to make them larger.