Controls & Sensors
Silicon: Smart and Strategic

by Tina Grady Barbaccia, Managing Editor

With the consistent move toward electronic controls and advancements in semiconductors, appliances have become smarter, and the controls and sensors marketplace has grown and become even more contentious. This is keeping suppliers hard at work to offer solutions that provide value and the latest technology.

Today’s control and sensor markets remain healthy, thanks in part to the demand from appliance makers for more functionality and performance with fewer components to increase reliability. Sales of semiconductors—used in controls and sensors—are up worldwide, and chip sales were, at press time, the highest since July 2000. According to the Semiconductor Industry Association (SIA), global semiconductor sales rose to U.S. $16.94 billion in April, a 36.6-percent increase from the same time last year. The U.S. market for sensor products—including sensors, transducers, and associated housings—alone is projected to rise 7.8 percent per year to $13.6 billion in 2008, according to a report from analyst firm The Freedonia Group. “A number of new sensor applications will spur rapid gains, particularly for advanced sensor technologies such as micro-electromechanical systems (MEMS), complementary metal-oxide silicon (CMOS), and optoelectronics,” the report states. “The rapid growth of digital cameras and cellular telephones with picture-taking capabilities will drive demand for imaging sensors in general and, more specifically, CMOS imaging sensors.”

Strong sales of cell phones have been a major contributor to increased chip sales, particularly for digital signal processors (DSPs), application-specific standard products (AASPs) in wireless, and Flash memory devices. These areas have grown by 6.8 percent, 8.8. percent, and 3.2 percent, respectively, according to the SIA. However, DSPs may have some competition. As handset applications such as multi-media and video functions have grown, there was the need to create an additional processor—the applications processor. The development of this processor has led to the emergence of a single processor cellular modem solution that can perform all of its operations in one core. Advantages of a single processor include lower overall royalties that would have to be paid and a smaller silicon footprint, which reduces cost and the printed circuit board area, respectively, as well as providing easier integration and easier debugging of combined software, according to Oyster Bay, NY, U.S.-based ABI Research.

Personal computer sales growth, coupled with increasing memory content in each computer system has also helped drive sales of the dynamic random-access memory (DRAM) technologies. Consumer applications such as next-generation PDAs, smart phones, and DVD players will continue to consume more DRAM, which will broaden the end markets for memory, according to a SEMICO Research Corporation report. The research firm says it believes that market growth will continue throughout 2004, with revenues increasing 30.8 percent to reach $21.5 billion.

Speed and Efficiency

All of these technological developments, the continued market growth, and price reduction of semiconductors have enabled appliances to become smarter, allowing more sensors to be used in real time, says Tom Ricono, senior product manager for Business Development, Diehl Controls North America, Inc. (Naperville, IL, U.S.). “Faster microprocessors allow real-time embedded systems to perform instantaneously, such as controlling motor speeds to rebalance [washing machine] spin loads as the imbalance happens and before it becomes a nuisance to the user,” Mr. Ricono tells APPLIANCE. “With increased inputs and outputs, larger code routines, and multiple calculations, being able to run at real-time and react instantaneously gives the appliance better performance and can save energy.”

Today’s sophisticated controls can also offer more than just intelligence and energy efficiency, adds Tom Glennon, vice president of Technology, Invensys Appliance Controls (Carol Stream, IL, U.S.). “They…can perform on platforms local to any region of the world and are designed and produced in a cost-effective manner,” he says.

Additionally, many believe the leading technologies will be those that have a good speed-to-market. Already an important factor, the quickly advancing electronic control marketplace has become more time-sensitive than many already say it is. “Outstanding quality, low price, and dependable support are not enough to stay competitive in today’s world of component supply for major appliances,” says Bob van Dusen, vice president, Spitfire Controls, Inc. (Barrington, IL, U.S.). “All of these attributes are merely the entry point. Time is now as critical a factor in control solutions as any other. Giving a competitor too much time in the market with exclusive features and benefits means a significant loss of market share.”

Small and Smart

The race toward protecting market share and having suppliers develop new relationships with OEMs continue to drive the move toward full electronic control of appliances. Control technologies have moved from mechanical to electromechanical to electronics, and this will continue to be the pattern because using electronics can enable functionality, increase reliability, and typically lower costs, says Stephen Caldwell, director, Home Appliance Solutions Group, Microchip Technology (Chandler, AZ, U.S.).

“ Electronic systems have ‘smart sensors’ that are more accurate than the mechanical component they replace,” Mr. Caldwell points out. For example, he says, bi-metallic switches and spring-activated components have been used as timers in appliances for years. “But it is possible instead to use simple electronics that deliver a more accurate and programmable timer, at a cost that is equal or lower to that of mechanical timers,” he says. “And, these electronic timers are more reliable, since they have no moving parts.” (For more information, see Perfect Timing.)

The trend toward electronic control is also driving a progression to distributed intelligence, Mr. Caldwell says. This means that instead of having only a mechanical temperature knob in a refrigerator, newer refrigerators will have multiple temperature and humidity sensors that bring a higher value to an appliance, he points out. This, coupled with basic electronics, enables appliance OEMs to offer such functions as zone control, where refrigerators can adapt their cooling systems to optimize food preservation based on food content and load. Other added functions include quieter, more energy-efficient motors and adaptive defrost controllers, which would lead to frost-free operation at optimal efficiency.

The continued move toward electronic control is also leading to the integration of smaller components and the integration of small sensors and microcontrollers within the same proximity, Mr. Caldwell says. Traditionally, sensors have been separate components that are constructed with various technologies. These traditional sensors can work in mechanical, electromechanical, or electronic systems. However, recently, sensor manufacturers have started making sensors with MEMS silicon technologies and integrating them into microcontrollers. “Sensors and electronics are becoming physically smaller,” Mr. Caldwell observes. “We expect appliance OEMs to take advantage of this trend by integrating the sensors and electronics into switches, knobs, and panels, in order to enhance the value of appliances.”

Even so, Mr. Caldwell expects the majority of sensors will remain as stand-alone components, independent of any other technology. “Appliance makers can take advantage of the flexibility that stand-alone sensors bring by matching sensor features with the needed electronics capabilities for their particular applications,” he says. “We expect integrated sensors to be reserved for high-volume, custom solutions that are able to support non-recurring engineering costs.”

A Solid-State Winner

Ultimately, electronics and solid-state sensing technology will prevail—not because they are cheaper, but because they are smarter, notes Gordon Swanson, business director, Fenwal Controls (Ashland, MA, U.S.). Mr. Swanson says for many types of appliances, both commercial and residential, simple, mechanical controls such as bi-metals and fluid-filled controls still offer reliable performance, low-cost, and easy servicing. “For basic temperature sensing and control on low-end products, they still make a lot of sense,” he says. “Of course, what these products don’t provide is any user interface, diagnostics, or the intelligence to offer, for example, energy-saving modes. With the rising cost of energy, we think that more manufacturers will look for ways to save energy via more intelligent control systems.”

This, he adds, will also increase the usage of solid-state sensing technologies that can provide variable data as opposed to mechanical products that are essentially on/off. “Mechanical controls will stay play a role, but it will be more of a secondary control feeding information back to an intelligent control,” Mr. Gordon offers. “This is really a continuation of what has been going on in the industry for years.”