Volume 4 | Issue 2 | Year 2001

Most of us expect the appliances we use to activate immediately after plugging in. We don’t worry about, or even think about, what’s really going on between the power being supplied at the outlet source and the conversion that’s going on when alternating-current power is transformed to direct-current power to operate an electrical tool or appliance. Cornell Dubilier of Liberty, S.C., does think about these things every day because its capacitors help with the transformation.

“We are niche people,” says Jim Kaplan, Cornell Dubilier’s president. “The electronics markets are huge, so we go after niches that the larger companies don’t have the capacity to service. A $100,000 account, for example, will require special needs like a little customization to their components. These are the companies we like to serve.”

“We like to think of ourselves as a specialty-capacitor company that goes out of its way to deliver better answers to capacitor design problems,” says Laird Macomber, director of market development. The $75 million (2000 sales) company employs 800 people and operates three facilities, each averaging about 100,000 square feet of space.

Expert Power
Cornell Dubilier is powered by some of the top minds in the industry. “We have more engineers here in our South Carolina facility than all four of our competitors combined,” says Kaplan. With this level of engineering expertise, the company delivers some spectacularly fast service. “When we receive a custom order, we can design it, spec it and ship in within a week, if that’s what our customer requires. That’s pretty remarkable in the industry,” Kaplan continues. “We have customers who have been let down by their suppliers. We help them get the products they need within a week.”

Expertise is one of the reasons Cornell Dubilier is able to offer this kind of service. The other is the company’s third shift, which allows this kind of critical flexibility to respond to customers’ immediate needs. “We will offer this kind of service at no extra cost,” says Kaplan. “We think it makes good business sense, and we know our customers will remember what we’ve done for them.”

Electrolytic Gurus
“Whenever you store energy as an electrical charge, the enabler doing the storage is the capacitor,” says Macomber. “Normally a capacitor is configured as one conductive plate separated from another conductive plate by an insulator. The bigger the plate area, the more capacitance you have. The thinner the insulator, the more capacitance – and the higher the dielectric constant of the insulator, the more capacitance. Dielectric constant is a multiplier showing how much capacitance you can get compared to separating the conductive plates with air. For instance, if inserting the insulator doubles the capacitance, the dielectric constant is 2.”

Macomber says capacitors like that are called electrostatic capacitors, and that they’re nice and simple. Cornell Dubilier, however, has its teeth into meatier capacitor applications. “We are involved more with electrolytic capacitors, and this is a whole other world,” says Macomber. He also notes that the company’s largest-selling products are its aluminum electrolytic capacitors.

“In the case of electrolytic capacitors, you have one conductive plate, but the insulator is grown on that plate, and the other plate – instead of being another metal plate – is a liquid electrolyte or a solid polymer electrolyte that was a liquid at one time,” explains Macomber. “So you’ve eliminated one of the plates and replaced it with a conductive fluid.”

The anode foil, the positive plate, is high-purity aluminum foil etched with billions of microscopic tunnels to increase the surface area up to 100 times. The foil is anodized to coat the tunnels and surface with aluminum oxide as the insulator. “If you can get the liquid electrolyte to penetrate down into those tunnels, you’ve also increased the capacitance up to 100 times. That’s a big advantage because more capacitance is better,” explains Macomber.

Keeping the liquid electrolyte in place are porous paper separators. “Then there’s a cathode foil that makes contact with the electrolyte, and the whole thing is wound up on automatic winding machines and the electrolyte is added after winding. The electrolyte penetrates into the papers and saturates the tunnels, and now you’ve got a capacitor,” continues Macomber. “The anode foil goes to the positive terminal and the cathode foil goes to the negative foil, allowing you to get a lot more capacitance than you could in any other way.”

Powering the World
Larger aluminum electrolytic capacitors are used in bus-capacitor applications – to power computers, for example. “AC voltages are coming out the wall socket and computers need DC voltage,” says Macomber. “So you have to run the AC through rectifying diodes and then apply the power to these bus capacitors to convert it to DC voltage.” That DC bus voltage is achieved using aluminum electrolytic capacitors. Some common applications include power supplies, motor drives and UPS systems. “The world is getting more and more digital, and power failures are increasingly more consequential. The market for UPS systems is growing at the rate of at least 15 percent a year and this is a major application for aluminum electrolytic capacitors,” he continues. Cornell Dubilier has a share of about one-third of this market.

The company’s film capacitors are used in some of the same power-conversion applications that use aluminum electrolytic capacitors. “But film capacitors work a lot better at higher frequencies,” says Macomber, noting that switching power supplies are a typical application. “The cost of a power-conversion system is determined partly by how much material you have to put into it. Because the power-conversion frequency coming out of a wall socket is 60 hertz, or 60 times per second, in order to run signals through transformers at that low frequency, you would need a lot of iron and a big transformer to filter the signal. Using a low frequency inherently means you need a lot of capacitance and a lot of iron in the transformer. This is where the idea of switching power supplies comes in.”

About 90 percent of all power-conversion systems use switching technology because it’s smaller and less expensive. Constant DC buses apply the voltage to a switching circuit that converts the energy to a very high-frequency AC. “The high frequency allows the AC to go through a very small transformer without much iron, and you have an overall savings in size, weight and cost,” says Macomber.

Cornell Dubilier manufactures film-chip surface-mount capacitors and solid-polymer-aluminum surface-mount capacitors – one of the company’s faster-growing segments. The company actively offers about eight capacitor dielectric systems for the variety of niche markets it serves. Among the major industries using Cornell Dubilier’s capacitors are data and telecommunications companies, and manufacturers of industrial systems such as motor drives and uninterruptible power systems.

Empowered Employees
A good barometer of a successful company is the amount of intellectual freedom it allows employees. “The hallmark of our management style is personal freedom and trust,” says Macomber. “I hire the best people and let them make the decisions they need to make, and I support them in that,” says Kaplan.

With its impressive assemblage of dedicated engineers, customers know they can depend on Cornell Dubilier to offer exceptional service and reliability. “We are unequivocally the best in customer service and the best in tech support,” says Kaplan. “Our customers know that if there’s ever a problem with their expensive systems, they can depend on us to be out there right away to help them.”

Cornell Dubilier will continue to maintain its position as power leader for components. “We plan to grow by offering as broad an array of products as we can offer,” says Kaplan. “Companies are always looking to reduce their vendor base, so we are not looking to grow bigger market shares. Instead, we will offer our current customers more.”