Analysis

After several weeks of testing (playing with) the finished product, the first concern that prompted immediate attention was the durability of the petri-dish because scratches, as well as small sub-surface cracks around the screw holes, started to appear. Although this was a cause for concern, it was expected because the petri-dish was classified as being cheap and disposable by the manufacturer. This cause for concern can be thwarted by using more robust types of petri-dishes that are reusable. Although, even with the improvement in durability, I personally would not like to cut and drill through one of these reusable ones because some are actually made of glass.

Electrical operation of the device remained within desired limits (it worked) over the course of many months and, as can be inferred from the current consumption below, continuous operation of the unit would be in excess of over 100 hours with two AAA batteries in series. Further improvements to the device could be made by either incorporating the virutal ground buffer proposed on page 4 or implementating a two stage gain for increased bandwidth since the Op-Amp IC used in this project contains two individual units.

Video

For the people who are unable to see the player itself on this web page, here is a direct link.

Music: BoA - Come to Me

Electrical Characteristics

Measurements, where applicable, were taken at a temperature of about 23 degrees Celsius.

• Operating Voltage: 2.8v-5.0v
• Minimum Current Consumption: 2.56mA @ 2.8v | 3.41mA @ 5v
• Maximum Current Consumption: 3.11mA @ 2.8v | 23.2mA @ 5v

Acknowledgments

Any individuals present below have not reviewed this write up and are in no way responsible for any errors.

• Dr. Poras Balsara
• Epanorama.net
• TangentSoft