Stamfam Science Saturdays: Parallel and Series

March 13, 2011

Inspiration
This is the more prep for Noelle's science fair project, this time focusing on both current and voltage and how they are affected by multiple spuds connected both in series and in parallel which she'll need to figure out how many spuds to use and in what arrangement to light up an LED.

Materials
4 wires with alligator clips - to connect the spud batteries in various configurations
3 potato pieces - to act as the electrolytic solution
3 galvanized nails - to act as anodes
3 pennies - to act as cathodes
1 pad of steel wool - to buff off any tarnish
1 multi meter - to read both mAmps and Volts (set to 2 mAmp and 20 V settings)

Notes
We measured each spud section's output after buffing the pennies to a nice shine to insure a good transfer. Each was putting out 0.9 +/- 0.1 Volts and 0.35 +/- 0.05 mAmps which Noelle dutifully recorded. We took some time to review Anode, Cathode, and Electrolytic Solutions along with what parallel and series meant for connecting them. We then measured amps and volts in various configurations demonstrating that Volts of were additive when the spuds are connected in series while current remained constant. With parallel configurations the volts remained pretty much a constant while current was additive.

We also wrote up Nelle's proposal for the science fair and just need to pick up an LED that will require a step up in both Current and Voltage from a single spud with no hints from daddy. I think she has enough knowledge to plan it out properly and make it happen with her spud power data she's collected over the last couple of weeks.