Parts And Materials, Continued
It just so happened that I had a Samsung brick at 4.75V DC just lying around. I really like the shape and size of this transformer because it is thin enough to be hidden inside the side cowls of the existing space. These transformers are used in all sorts of electronic components and are readily available on eBay for $5.00.
The Paper Shredder (Qty - 2): I tried many, many paper shredders out there before I found one I was satisfied with. Believe it or not, I chose a $15 shredder from Wal-Mart in the end. The Aurora 5 Sheet Strip-Cut Paper Shredder was the fastest paper shredder I could put my hands on. It has only a strip type cutter in it, but that's good enough for our needs. It also sports thermal overload protection on the motor and will shut itself down before "unsafe" conditions are met. Not to mention when we are done with the shredder, or when it wares out, we can bring it back to Wal-Mart, and their highly trained staff will most likely take it back and refund our money.
The solenoid controller: The solenoid controller is the key to this unit. This is basically nothing more than a glorified LED Flasher, but instead of LEDs, we will drive the solenoids in the printer with its output. The speed of the flash (or drive-rate in this case) can be hard set via resistor, capacitor or variable. After some tinkering with a bread board, we chose a basic circuit to drive the solenoids for a feed rate that doesn't overload the paper shredder. We built redundant circuits to control the solenoids on the upper tray and lower tray independently, thus allowing for independent feed rates as well.
One note on power tools: use them at your own risk. Be sure to read and understand any and all documentation for the tools you use. No amount of documentation can make up for experience, but there are many people with serious eye injuries at the school of hard knocks. If you don't know what you're doing, don't do it and find someone that can help.