Team 4 The Beancounters Ethan Price, Shicheng Guo, Wesley Tso, Kyle Haver

Solid State Relay Considerations Control signals need minimal amounts of current: ~30mA. Standard 10mil trace will suffice SSR1: Mounted on the PCB, will have to pass 1.7A of 20VDC for the fan. This will need to have >50mil traces and molex connectors, plus etxra space between traces SSR2: Mounted separately from PCB

I2C Considerations 100KHz operation; noise, impedance, and signal length possible concerns (rated to ~1m) Rule of thumb: <1/10 of wavelength, transmission line effects not a concern I2C fall time is about 100ns = 5MHz = ~100meters We're well under 10 meters, not concerned

Power Supply Conversion: 12.6VAC -> ~12VDC -> 5VDC As with SSR, needs to be relatively isolated 7805 will need heatsink, so some keepout area will be needed Header pins are rated at 1A each, should be sufficient for power supply

Microcontroller All voltage pairs have decoupling caps, need to be placed nearby Want to attempt to keep uC and headers away from switching noise of amplifier and transistors Crystal and associated caps are slammed up against the microcontroller