Apple turns 50 this year and you can celebrate by bidding on Steve Jobsâ eighth-grade science fair project.

The project, titled âWhat Is the Silicon-Controlled Rectifier?,â is one of 212 lots being sold as part of RR Auctionâs Steve Jobs & the Computer Revolution: The Apple 50th Anniversary Auction Part Two. The auction, which closes Thursday, is meant to trace Appleâs ârise from a Los Altos garage to a global technology powerhouse.â

The first part of the auction took place earlier this year and included the first check ever issued by Apple, signed by Jobs and Steve Wozniak. The $500 check was issued in 1976 to Howard Cantin, who designed the Apple-1âs printed circuit board. It ultimately sold for a mind-blowing $2.4 million.

This time around, there are sealed first-generation iPhones, iPods and other pieces of vintage Apple hardware. There are also personal items belonging to Jobs, including signed business cards, letters, and framed photos that once hung in his familyâs home.

But one of the most unique items is something Jobs built years before Apple even existed.

Dated February 29, 1968, the school project includes a 10-page report and a three-panel plywood display about silicon-controlled rectifiers, semiconductor devices used to control electrical power. At the center of the display are two test circuits. Jobs wrote that one was “designed to demonstrate the basic principals and characteristics of the silicon-controlled rectifier” while the other was “designed to demonstrate how the silicon-controlled rectifier is used in its most widely accepted application; motor speed control, light dimming, etc.”

Jobs even left a note for the science fair judges reminding them to âplease unplug!â the second circuit after using it.

According to RR Auction, the project comes from the personal collection of Jobsâ stepbrother, John Chovanec. It remained in the Jobs familyâs Los Altos home for decades after Jobsâ father, Paul, died in 1993. Chovanec said that both he and his mother repeatedly encouraged Jobs to take the project, but he declined. Eventually, Chovanec took it to his own home and kept it ever since.

RR Auction estimates the project could sell for more than $20,000. As of Tuesday afternoon, it had received 13 bids, with the current bid sitting at $3,222.

But if eighth-grade science projects arenât really your thing, the auction has plenty of other pieces of Apple history to choose from.

The item with the highest current bid is the âNeumarkâ Apple-1, a fully functional 1977 computer housed in a Smith-Corona typewriter case. As of Tuesday afternoon, bidding had reached $205,000.

The next most expensive item is a 1983 Apple Computer business card signed by Jobs. As of Tuesday afternoon, the current bid is $103,574.

There are some slightly more affordable options too. A collection of 11 original âsilhouetteâ advertising posters from 2007 promoting the iPod is currently going for $440, while a prototype Apple PowerBook Duo 270c notebook computer is sitting at just $430.

The cheapest lots on Tuesday were both sitting at $10 and included four Apple Computer presentation folders with unused stationery and a collection of six Apple Computer training systems.

Bidding for the auction closes August 20.