Analog Lab 02 Breadboard IO

Goals:
To connect components to the breadboard which allow for signals to be input and output from circuits on the bread board and allow experimenters to manipulate said signals.

Supplies/Tools:
Audio source (laptop, iphone, function generator)
Headphones (even earbuds will work)
3.5mm audio cable,

Circuit:
Starting with the circuit from Lab 01 we will solder the audio input breakout board and add resistors and capacitors as seen here.  With this breakout board, you can connect your headphones to the breadboard to listen to the signal.  Also you can connect your headphones via hook-up wire, but this is only a short term solution.

Experiments:
Play audio from your source to the breadboard and connect wires directly between the input and output, with no resistance in between.  During lab only cover one ear, so that we can also discuss observations and variations on the below.

Add resistance to the signal (via fixed or variable resistors).

Add capacitors to the signal:
1.  signal going through a capacitor to the headphones
2. signal bypassing to ground via a capacitor.  This means the signal goes both directly to the headphones and through the capacitor to the ground rail.
3. Quickly test different capacitor values.

Remove the resistor and capacitors, add diodes to the signal.

Questions:
How much resistance would it take to half the amplitude of the signal?  Or what configuration of resistors would be required to half the amplitude?     If you produced results experimentally, what did you do?

How did capacitors change this signal quality (if at all)  what capacitors did you use?

Did diodes change the signal?  How did you add them to the signal path?

Final Project:
Of the 3 ideas you reviewed last week, pick one,  discuss how you would change it:   1.  With complete ignorance of what would be involved, discuss what you would change to make it more musically usable or expressive.  2. With practicality on your mind, discuss how you would change the project to make it more viable for the electronics lab final project.  Things to address in considering viability: Must use parts from lab, no mystery parts; must be reasonably achievable (see feedback from instructors); , must not be too simplistic, a final project should combine several lab circuits…  see blog for examples of circuits for future labs.

Sign up for a free student account at CircuitLab with your NYU email address. CircuitLab is an amazing web app that easily lets you draw schematics (standardized circuit diagrams) of your circuits. After you sign up, spend 15 minutes trying to make a schematic for any circuit you’ve made, even one of the simpler ones from Lab 1. Bonus points if you can make schematics for one or more of your circuits from Lab 2, and can integrate them into the main section of your Lab Report. We be pushing you to do this more as the semester continues.

Schematics are how all electrical engineers and circuit designers share their circuit designs with each other. The symbols for different parts in CircuitLab are standardized symbols that everyone everywhere uses. By the end of the semester we will expect everyone to make schematics for their Final Projects. That way, you can easily share your unique, custom audio circuits with anyone who either wants to know how you made them, or wants to make their own. A huge amount of learning electronics comes from studying other people’s circuits and schematics.

Advertisements