I began by using Ansys workbench to run non-linear FEA on different speaker surround designs to identify a profile, material, and thickness that met goals for guiding the motion of the speaker cone with minimal resistance while keeping strain below an allowable maximum value. I first built an improvised force/displacement test fixture to capture stress/strain values for candidate materials and use that data to extract coefficients for a hyper elastic material model to use in the non-linear FEA solver. We then iterated on several approaches and identified a section and thickness to use within an upcoming build.

syng surround

The designers had conceived a control ring to be used for audio transport that required a ring that could provide three discrete degrees of freedom and tactile profiles. Additionally, the ring was collocated with the AC power interconnect and system microphones. I began by designing and building a set of usability mockups where the tactile force profile of each interaction could be modulated and experienced in order to establish a target profile for each.

I then worked with ID on a series of design iterations developing an integration that achieved the target interfaces while also achieving system interconnect and structural interface goals. The tactile input profiles were achieved through a combination of linear and bistable spring elements and complex magnetic circuits. I used Ansys Maxwell to develop the magnetics, and a combination of analytical modeling and structural FEA to develop spring elements. The motion was measured with specialized surface tracking ICs as well as traditional hall effect sensors. I worked with audio engineering to integrate microphones and EE and develop a PCBA. And with the rest of the PD team to converge on an assembly flow and system structural interface.  I then prototyped the design using custom extrusions springs, extrusions, and magnets that I sourced from vendors in my personal network. The prototype worked well and achieved the desired functionality in the space available and was substantiated to be manufacturable with a series of TA’s and force models.

cr1

cr2

sensing

I then brought the module to personal contacts at Foxlink, IAC, and Wistron to scope a manufacturing effort, resulting in two potential paths forward.  However, the design had a relatively larger number of components and assembly steps for an input device and the product team decided to defeature the functionality.

I developed designs for mounting and locking the device to stands and also developed detailed designs for the various stands based on ID inputs and DFM requirements.

locking

I engaged a compliance consultant from my network to review our power supply architecture and identified critical requirements of clearance and creepage distances, as well as restrictions on installation configurations. I worked the the power supply designers and other PD engineers to develop an enclosure solution that met the required distances and developed an approach to meet the electrical code requirements while still achieving the desired user experience with a retrofit component for fixed installations.