Reduced Part Count Research Articles

Practical use of statistically modified laminate model for injection moldings

Injection molded fiber reinforced materials offer designers the opportunity to reduce part count in a wide range of consumer products. However, flow induced orientation of the fiber results in anisotropy of material properties, and can lead to concerns regarding stiffness and warpage. In previous work the authors introduced a method for predicting anisotropic stiffness, and evaluating warpage, for this class of materials using empirical data derived from tests performed under conditions close to those used in manufacturing. In this paper the method is used to predict with a high degree of accuracy the variation in bending stiffness within a corner injected plate. It is also used to illustrate sensitivity in linear and buckling warpage modes, and show how small changes in process conditions can completely change the predicted warpage pattern.

IBM S/390 Parallel Enterprise Server G5 fault tolerance: A historical perspective

Fault tolerance in IBM S/390® systems during the 1980s and 1990s had three distinct phases, each characterized by a different uptime improvement rate. Early TCM-technology mainframes delivered excellent data integrity, instantaneous error detection, and positive fault isolation, but had limited on-line repair. Later TCM mainframes introduced capabilities for providing a high degree of transparent recovery, failure masking, and on-line repair. New challenges accompanied the introduction of CMOS technology. A significant reduction in parts count greatly improved intrinsic failure rates, but dense packaging disallowed on-line CPU repair. In addition, characteristics of the microprocessor technology posed difficulties for traditional in-line error checking. As a result, system fault-tolerant design, particularly in CPUs and memory, underwent another evolution from G1 to G5. G5 implements an innovative design for a high-performance, fault-tolerant single-chip microprocessor. Dynamic CPU sparing delivers a transparent concurrent repair mechanism. A new internal channel provides a high-performance, highly available Parallel Sysplex® in a single mainframe. G5 is both the culmination of decades of innovation and careful implementation, and the highest achievement of S/390 fault-tolerant design.

Advanced nickel/hydrogen dependent pressure vessel (DPV) cell and battery concepts

The dependent pressure vessel (DPV) nickel/hydrogen (NiH 2) design is being developed by Eagle-Picher Industries, Inc. (EPI) as an advanced battery for military and commercial aerospace and terrestrial applications. The DPV cell design offers high specific energy and energy density as well as reduced cost, while retaining the established individual pressure vessel (IPV) technology, flight heritage and database. This advanced DPV design also offers a more efficient mechanical, electrical and thermal cell and battery configuration and a reduced parts count. The DPV battery design promotes compact, minimum volume packaging and weight efficiency, and delivers cost and weight savings with minimal design risks.

Low Power Design for Wireless RF Transceiver–An Industrial View

In recent years, wireless communication in the radio frequency has a rapid growth, most noticeably the cellular phone. Analog FM systems, such as AMPS and TACS, have won a great success. In the 90s, digital systems appear, such as GSM in Europe, IS54/136 and IS95 in US, and PDC in Japan. Most recently, PCS draws the attention; there are many standards proposed around the world and they all use digital modulation schemes. With the ISM bands at 900 MHz and 2.4 MHz, many other innovative application will become possible. Unlike the computer such RF wireless gadgets contain one peculiar subsystem: the RF transceiver. The RF transceiver translates the baseband voice and data to and from a radio frequency signal which is emitted and received by antennae. Each system specifies the operation frequency, the transmit power, the receiver sensitivity, and the signal quality. The RF transceiver must satisfy all these requirements. As technology progresses, portable product becomes the dominant one which relies on the rechargeable battery. To maintain a decent talk time standby time, the completed product must be designed with low power consumption in mind. In the portable cellular phone the RF transceiver faces the greatest challenge in the low power design since it is the most power hungry portion: the transmitter consumes 90% power during transmission in the FM cellular phone nowadays. To achieve low power consumption of the RF transceiver, the designer has to work to: (1) transceiver architecture to reduce parts count and therefore power comsumption. (2) selection/design the lowest power comsumption IC/module for a given function block. (3) maintain competitive pricing and small size. In this article, FM system will be used as the baseline example to illustrate the importance of the RF transceiver in low power application. The RF transceiver architecture is described first, followed by the introduction to each function block. State-of-the-art products for each function block will be referred to. Theorectical limit of power consumption for each block will be discussed. Impact from digital modulation on RF circuit design will be reviewed as well.

Advanced developments in NiH/sub 2/ Dependent Pressure Vessel (DPV) cell and battery technology

The Dependent Pressure Vessel (DPV) Nickel-Hydrogen (NiH/sub 2/) design is being developed by Eagle-Picher Industries, Inc. (EPI) as an advanced battery for military and commercial, aerospace and terrestrial applications. The DPV cell design offers high specific energy and energy density as well as reduced cost, while retaining the established Individual Pressure Vessel (IPV) technology flight heritage and database. This advanced DPV design also offers a more efficient mechanical, electrical and thermal cell and battery configuration and a reduced parts count. The DPV battery design promotes compact, minimum volume packaging and weight efficiency, and delivers cost and weight savings with minimal design risks.

Compression Response of Thick Layer Composite Laminates with Through-the-Thickness Reinforcement

Compression and compression-after-impact (CAI) tests were conducted on seven different AS4-3501-6 [0/90] 0.64-cm thick composite laminates. Four of the seven laminates had through-the-thickness (TTT) reinforcement fibers. Two TTT reinforcement methods, stitching and integral weaving, and two reinforcement fibers, Kevlar and carbon, were used. The remaining three laminates were made without TTT reinforcements and were tested to establish a baseline for comparison with the laminates having TTT rein forcement. Six of the seven laminates consisted of nine thick layers whereas the seventh material was composed of 46 thin plies. The use of thick-layer material has the potential for reducing structural part cost because of the reduced part count (layers of material).

Design‐for‐assembly through knowledge application

Reduced part count is a powerful cost‐saving element of design‐for‐assembly systems. A method has been developed in which component function and relationship data are used to present advice to the designer.

Advantages of microprocessors versus discrete digital electronics in appliance controls

The use of 4, 8, and 16 bit microprocessors versus discrete digital electronics in appliance controls is discussed. The categories set forth are not intended to describe all microprocessor parts available, but rather to address general microprocessor technologies. Simple controllers that can compete in applications typically relegated to switches and mechanical timers are discussed, as well as more complex controllers such as those providing novel and useful features for top-of-the-line appliances. Guidelines are assembled for use in choosing the right processor for the job. A typical microprocessor-based control project life, from concept to finished product, is discussed. The costs associated in microprocessor design, development, and modification during the embryonic phase are addressed. The use of microprocessor technology versus discrete digital circuitry results in reduced parts count, smaller circuit boards, improved performance/reliability, potential cost reductions, increased flexibility, and decreased response times.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

New Lossless Turn-On and Turn-Off (Snubber) Networks for Inverters, Including Circuits for Blocking Voltage Limitation

Transistorized pulsewidth modulated (PWM) inverters require careful dimensioning of turn-on and turn-off circuits in order to minimize switching loss in the power transistors. New lossless circuits are described. In particular the turn-off circuits show a highly reduced part count compared to circuits known from the literature. The turn-on circuits apply energy recovery. Furthermore, due to a special circuit the voltage across the power transistor is strictly limited. This is important especially due to the usually low voltage blocking capability of high-current power transistors.