using electronic system cooling analysis software led to considerable cost savings as well as improvements in product quality for gtech's latest innovative lottery game system.

innovation and leadership

gtech is the world's number one choice for on-line lottery technology and services. all around the world, people are playing the lottery for fun, to help fund good causes, and with the hope of striking it rich. but no matter where they play, the odds are that they're playing on a gtech system. gtech systems securely handle billions of transactions per year - up-time exceeds 99 percent and system reliability is critical.

ezexpress lottery terminal

ezexpresstm marks the beginning of a new era in the retail lottery industry and is designed and packaged to meet the needs of a challenging retail environment. it is a self service lottery terminal designed for easy play and direct interaction with the customer. ezexpress fulfills the retailersrequirements by providing attractive entertainment for customers with no extra work for busy staff. ezexpress sets a new standard in flexibility.

side and front views of the terminal's sheet metal enclosure showing air flow velocity vectors.
within the enclosure is a power supply, cpu unit, communications boards, printer with paper roll, ticket reader,
bill acceptor, lcd panel, touch sensitive panel and several lighting units.

the system had to be designed for low maintenance and wide distribution. the terminal accepts bills, dispenses tickets and allows for semi-account wagering through a voucher credit system. the unit can be configured to support a wide range of lottery games.

design objectives

the ezexpress terminal design was new from the ground up; prototypes had never been built. the thermal design criteria were severe since the unit must operate in hot ambient conditions. in addition, lcd panels, ticket readers and bill acceptors are particularly sensitive to operating temperatures. within the enclosure is a cpu unit and ticket printer unit that had additional cooling requirements. minimizing the need for fans as well as minimizing the size of external openings was a requirement. the cooling problem was quite complex. gtech called on maya to help solve the thermal issues.

simulation approach

the ezexpress enclosure contained many devices including a cpu, printer, lcd, key-pads, ticket reader, bill acceptor, power supply and lighting units. of particular concern was the lcd panel since its readability is temperature sensitive and it is quite close to several lighting units. the cpu unit is contained in a separate enclosure along with communications boards - this required fan cooling. additional lamps located in the card and bill insertion bezels were of concern since the lamps were close to surfaces which can be touched by the customer.

keeping the lcd panel cool was critical for readability and reliability. maya's thermal engineering
expertise was utilized to help optimize the design of a heat shield between a lighting unit
and an lcd panel. adequate shielding without restricting air flow over the panel was a challenge.
the analysis software permitted detailed modeling of natural convection and radiation from the bulbs.

working directly from gtech's solid design geometry the engineers analyzed the baseline design using maya's thermal simulation tool electronic system cooling (esc). four separate models were created: a system level model for the terminal, and detailed models for the cpu, lcd panel, and bezel light. complex radiation patterns and the particular fan characteristics had to be modeled in detail. this approach allowed overall temperature and air flow predictions within the unit, as well as detailed analysis of critical components and areas. the simulation revealed potential thermal problems in the lcd panel, the cpu, and the bezel-bulb assembly.

solving the thermal problems together

maya's recommendations to place a fan in the cpu box and to provide improved venting and shielding over the display seemed feasible to the gtech design team. numerous iterations were necessary to achieve an optimal design. frequent communication back-and-forth with the designers eliminated potential problems such as airflow blockage by the printer paper. venting for the complete enclosure was optimized in order to eliminate the need for additional cooling fans. eliminating the need for a fan on the power supply by designing special vents, ducting and positioning of the power supply saved production costs.

a fan mounted on the top inside of the cpu enclosure cooled the main cpu board and
the communications cards below. this was the only fan required in the system.
balancing the vents in the cpu and option boards enclosure was key to
ensuring adequate cooling of all components.

maya helped gtech meet the design goals and by working together the design was both timely and cost effective. finally, a physical prototype was built and the analysis results were experimentally verified with good correlation. the design was a success and product trials have shown excellent performance.

maya heat transfer technologies ltd.
4999 st. catherine st. west, suite 400
montreal, quebec, h3z 1t3

visit maya at www.mayahtt.com

©1997, maya heat transfer technologies ltd.
ezexpresstm is a trademark of gtech corporation.
all product photos courtesy of gtech corporation.