Low Power Electronics

Class D Amplifiers

The focus of IPRO 344 is to capture and deliver superior sound quality at drive-thru restaurants. To accomplish our goals, we have employed industry leading electronics. Microphones made by Shure allow us to successfully capture the customer's voice, while class D amplifiers by Texas Instruments regenerate the signal during transmission.

This semester we made three large additions to our system. First, we added an audio mixer which allows us to mix up to four channels of audio into one signal prior before being passed to the other side of the system. Second, we added an audio equalizer which allows us to control the volume on various frequencies in the signal. It is our hope that utilizing the equalizer properly, we will be able to increase the speach intelligibility of the system by using proper adjustments. Lastly we added what we call the client priority gate. This piece of circuitry cuts off audio on one side of the system while the opposite side is sending a signal and vice versa. This helps to cut down on feedback issues, and will hopefully help individuals on either side to communicate more effectively.

Some smaller modifications we made to our system are as follows. We made some improvements on old components to increase energy efficiency. We also created printed circuit boards for all of our circuits which has allowed us to condense the chassis, providing more space in the kiosk for additional components. Some of the components were also moved out of the kiosk into a server station, which has controls that can modify the system without opening the kiosk.