Specifications

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openings are set at 0.1” spacing (2.54mm) to standardize them for use with
standard spaced interconnect headers.
Figure 3.6.3-2: A simulated, rendered image of the PCB layout.
A simple two-layer board was chosen. Additional layers can simplify routing and
create a more compact overall circuit, but also increases cost. Given our level of
complexity for the designed schematic, a two layer board would most likely be
sufficient. The size of the board was chosen at 3in x 2in. Thickness was chosen
to be 0.062”. While space is at a premium in the portable unit, there should be
sufficient space to fit a 0.03” thicker board. The additional thickness should also
help increase durability of the board.
3.7 Control/Base Unit Circuit Board
3.7.1 Choice of Circuit Board for Control/Base Unit
The control or base unit will not require as much circuitry as the portable unit did.
The primary reason for this is that no rechargeable battery will be used for the
control unit, as it will be powered directly from the vehicle’s electrical system.
Given this fact, the same options that were considered for the portable unit were
also considered for the control unit.
However, one possible option was to design the circuit above to also be
compatible with the control unit. Doing this would yield significant cost savings as
it would then only be necessary to commission a single printed circuit board
rather than two separate boards. Given the minimum order quantities at the
majority of custom PCB manufacturers, this would yield a cost savings
regardless of manufacturer chosen.
3.7.2 Creating a Dual-Purpose Board