Smart techniques for flying-probe testing

In the production of printed circuit boards, in-circuit tests verify whether the electric and electronic components of the board have been correctly soldered. When the test is performed using flying-probes, several probes are simultaneously moved on the board to reach and touch multiple test points. Taking into consideration the layout of the board, the characteristics of the tester, and several other physical constraints, not all movements of the probes are mutually compatible nor they can always be performed through simple straight lines. As the cost of the test is mainly related to its length, and patching the path of one probe may create new incompatibilities with the trajectory of the other probes, one should carefully trade off the time required to find the trajectories with the time required by the probes to follow them. In this paper, we model the movements of our flying probes as a multiple and collaborative planning problem. We describe an approach for detecting invalid movements and we design a strategy to correct them with the addition of new intermediate points in the trajectory. We report the entire high-level procedure and we explore the optimizations performed in the more expensive and complex steps. We also present parallel implementations of our algorithms, either relying on multi-core CPU devices or many-cores GPU platforms, when these units may be useful to achieve greater speedups. Experimental results show the effectiveness of the proposed solution in terms of elapsed computation times

Automatic Testbench for PCB

Táto diplomová práca sa zaoberá problematikou praktického návrhu a realizácie tes-tovacieho prípravku pre fyzioterapicku jednotku. Cieľom práce bolo navrhnúť a realizovať funkčný tester a vytvoriť vhodný užívateľský program pre daný tester. Následne vypracovať ekonomickú analýzu.This diploma thesis deals with practical aspects of a Functional tester of Printed Circuit Board. The main goal was to design and create a Functional tester for Printed Circuit Board. Also to create suitable software for automated tester unit; and to construct an economic analysis

Insulation considerations and qualifications for form-wound air-core armature windings in high-frequency electrical machines

High specific power electrical machines are a key enabling technology in hybrid electric aircraft. Specific power can be increased by increasing the machine's electrical loading and operating frequency, which often increases the machine's operating temperature and requires a strong insulation scheme. This thesis will explore the insulation scheme implemented in a high specific power permanent magnet synchronous machine currently being developed by the Haran Research Group. The insulation, initially developed by other members of the group, will first be summarized. The machine and drive system will then be examined in a system context to determine the possibility of voltage overshoot at the motor terminals caused by a variable frequency drive along a transmission line. Based on simulation results, recommendations for future work in the insulation system are made. The remainder of the thesis will focus on developing a test plan for the existing insulation scheme through the use of dc hipot testing and impulse winding testing. The work concludes by appointing successors to continue winding validation and begin an exploration of accelerated aging behavior in the author's absence. Appendices provide a step-by-step guide to the impulse winding test and printed circuit board designs with photographs of windings under test

Heater Control for Thermionic Power Generation

The purpose of this report is to detail the conceptualization, analysis, budget, manufacturing, and assembly the heater for a thermionic energy converter for portable energy generation. This proof of concept will be created to provide a full thermionic energy converter with a reliable and satisfactory heater than can be used in future systems. The report highlights the feasibility and realities in the design and fabrication of the system

NASA Thesaurus. Volume 2: Access vocabulary

The NASA Thesaurus -- Volume 2, Access Vocabulary -- contains an alphabetical listing of all Thesaurus terms (postable and nonpostable) and permutations of all multiword and pseudo-multiword terms. Also included are Other Words (non-Thesaurus terms) consisting of abbreviations, chemical symbols, etc. The permutations and Other Words provide 'access' to the appropriate postable entries in the Thesaurus

NASA thesaurus. Volume 2: Access vocabulary

The Access Vocabulary, which is essentially a permuted index, provides access to any word or number in authorized postable and nonpostable terms. Additional entries include postable and nonpostable terms, other word entries, and pseudo-multiword terms that are permutations of words that contain words within words. The Access Vocabulary contains 40,738 entries that give increased access to the hierarchies in Volume 1 - Hierarchical Listing

NASA Thesaurus. Volume 1: Hierarchical listing

There are 16,713 postable terms and 3,716 nonpostable terms approved for use in the NASA scientific and technical information system in the Hierarchical Listing of the NASA Thesaurus. The generic structure is presented for many terms. The broader term and narrower term relationships are shown in an indented fashion that illustrates the generic structure better than the more widely used BT and NT listings. Related terms are generously applied, thus enhancing the usefulness of the Hierarchical Listing. Greater access to the Hierarchical Listing may be achieved with the collateral use of Volume 2 - Access Vocabulary

NASA thesaurus. Volume 2: Access vocabulary

The access vocabulary, which is essentially a permuted index, provides access to any word or number in authorized postable and nonpostable terms. Additional entries include postable and nonpostable terms, other word entries and pseudo-multiword terms that are permutations of words that contain words within words. The access vocabulary contains almost 42,000 entries that give increased access to the hierarchies in Volume 1 - Hierarchical Listing

NASA thesaurus. Volume 1: Hierarchical Listing

There are over 17,000 postable terms and nearly 4,000 nonpostable terms approved for use in the NASA scientific and technical information system in the Hierarchical Listing of the NASA Thesaurus. The generic structure is presented for many terms. The broader term and narrower term relationships are shown in an indented fashion that illustrates the generic structure better than the more widely used BT and NT listings. Related terms are generously applied, thus enhancing the usefulness of the Hierarchical Listing. Greater access to the Hierarchical Listing may be achieved with the collateral use of Volume 2 - Access Vocabulary and Volume 3 - Definitions