Tim I, Bill P, Jose, Aaron, Tyler
September 23, 2010 Bill P has been working on controller electronics. Team members volunteer to be a part of it. Due date added to Requirements.
September 26, 2010 I have changed directions on the hardware. Originally started with Arduino and the OneWire library with a DS1820 temp sensor. Change to use the Wiznet WIZ200Web module (Atmega128 with Wiznet W5300 on one module) and still using the DS1820. Made this change so that we did not have to have a PC running to control it. Now it will be Web based and will send email alerts when out of control. That way a text message can be sent as well.
October 23, 2010 Cryo was able to reach ~ -55 C and held for ~ 2 hours with 11 lbs of dry ice. Fan was on continuous for the duration of the test.
Requested completion date: Oct 15
Physical
Internal dimensions
Contain a payload stack measuring 18x18x36 inches, with at least 4 inches air space around all sides
space for dry ice reservoir below payload + future modification for small ballast liquid drain/exit chute out a lower side/corner
Bulkhead passthrough for running cables to the payload - perhaps a ~4” hole that can have removable plugs of insulation to customize to different wire arrangements. Recommend doing this in any upper corner
Provide a full length bar across the top of the inner lid that can support 15 lb weight, and has 1” clearance from top surface to allow hooks to be passed over it
Temperature requirements
Able to maintain -60C continuously for 72 hrs
Hold enough dry ice for 72hrs of operation without adding more
Thermal control should be able to establish at least min 2 degrees C/ min change
Interpolate temp linearly between simulation file data points
User interface
Dryice handling gloves!!!!!!!!!!!!!!!
