Electronics III: Week 6

After last weeks midterm I needed to take the time to do more research on the design of my active crossover, in regards to slope of the filter. This required me to do some more math for the values of my  components. I decided to go with:

High Pass:
Resistor: 8 K Ohms
Capacitor: 10 nF
Cutoff Frequency: 1989 Hz

Low Pass:
Resistor: 15 K Ohms
Capacitor: 10 nF
Cutoff Frequency: 1061 Hz

Due to the long slope of the Salen-Key Filter I had to increase the distance of the cutoff frequency in order to achieve a better separation for the tweeter and midrange driver. Now that I am satisfied with the design its time to get the crossover on a chip.

I received my audio amplifier kit in the mail on the friday before our midterm, so I was excited all weekend to get to work. When I opened it i was amazed at how easy the kit really was. So I decided to buy two individual audio amps to power separate speakers. With help from Sudhu I realized that If I want to use my stereo audio amp for one driver I would need to electrically "Bootstrap" the circuit. This   creates more impedance and therefore more signal to a single output. I did some research and read that bootstrapping is a technique in which the output of the signal is fed back to the node that is normally connected to ground. This positive feed back loop alters and increases the impedance allowing for more signal flow. The use of bootstrapping was usually necessary in the early days of bipolar transistors and is commonly used in AC amplifiers to increase output swing.

Here is my first of two Audio Amplifiers in progress: