EPS Detailed Design¶

• EPS Detailed Design
  • • Introduction
    • Design Criteria Review
    • Block Diagram
    • Schematic
    • Bill Of Materials
    • Budget

Introduction¶

While the preliminary design is nearly a complete detailed design, the PCB design needs to be completed before assembly can begin. This will be completed while parts are on order, as some have a 2-3 week lead time in the quantities required.

Design Criteria Review¶

• EPSRR 1.1 The EPS board uses a Texas Instruments MSP430 microcontroller to measure and store the sensor data
• EPSRR 1.2 the EPS board is made from components which are rated beyond the specification as listed, and the system will operate without direct intervention by an operator.

• EPSRR 2.1 The EPS board is designed in such a way that it may be installed by any person with solar power or electrical wiring experience.
• EPSRR 2.2 The EPS board will have screw holes to mount the board using #10 screws. Alternatively, a DIN rail clip may be used.
• EPSRR 2.3 The EPS board can draw it's power from either monitored load or from another 6-30VDC source.

• EPSRR 3.1 The EPS board shall measure predefined parameters.
  • EPSRR 3.1.1 The EPS board measures the ambient temperature in the enclosure using a sensor on the board.
  • EPSRR 3.1.2 The EPS board measures voltages of two separate circuits directly with a chip that has built in isolation.
  • EPSRR 3.1.3 The EPS board limits the input voltage to the sensor to safe levels using a zener and current limiter.
  • EPSRR 3.1.4 The EPS board measures the current of two separate circuits using a directly with a chip that has built in isolation.
• EPSRR 3.2 The EPS board transmits measurement data or fault conditions to the server using a MAC chip with full TCP/IP stack.
  • EPSRR 3.2.1 The EPS board will transmit measurement data on demand (web page request).
  • EPSRR 3.2.2 The EPS board will be capable of transmitting measurement data on a schedule (FTP or email).

• EPSRR 4.1 The EPS board consumes minimal power. Design maximum is 24mW.
• EPSRR 4.2 See EPSRR 2.3.
• EPSRR 4.3 The EPS board meets all criteria in this area, having a tolerance for massive overvoltage and 12 bit accuracy.
• EPSRR 4.4 The EPS board measures temperature within from -20 to 85C with 12 bit accuracy.
• EPSRR 4.5 The EPS board meets all criteria in this area, having a tolerance for massive overcurrent and 12 bit accuracy.
• EPSRR 4.6 The EPS board meets all criteria in this area, having a MAC controller IC with a fully functional TCP/IP stack and Ethernet Jack with Magnetics.

• EPSRR 6.1 The EPS board is read using standard web protocols which are standardized across all platforms.
• EPSRR 6.2 The EPS board uses standardized connections including Screw terminals and Ethernet.
• EPSRR 8.1 The EPS board is optimized for ease of production.
• EPSRR 8.2 See ESPRR 8.1.

• EPSRR 9.2 The production units appear to cost around $60.00 in parts.

• EPSRR 11.4 Attention has been paid into the durability of the design to keep waste to an absolute minimum.

Block Diagram¶

Schematic¶

Bill Of Materials¶

Budget¶

Note: this budget reflects 8 hours of PCB layout which will be complete by 25 FEB 2013