Almost three years ago, seeking a friendlier manufacturing climate and proximity to a medical center, Dave Sauerwald packed up his Bridgewerks business and his extended family and moved from Laguna Hills, Calif., to Durham.

Now, he is resettled -- the family onto a Durham cul-de-sac and the business onto Hunt Street. There, Sauerwald and his five employees manufacture what his Web site modestly describes as "the finest model railroad power supplies in the world."

"It's a fun kind of business," he said. "We found kind of a niche because there wasn't anything of quality."

Rick Smith at Tom's Train Station, a Raleigh retailer, said Bridgewerks' products are pretty good.

"In the industry, they are one of the best known for making high-quality, dependable power supplies," Smith said. "Very, very rugged ... all of the controls very easy to use.

"I have yet to have any item that they manufactured returned to this store defective. Zero."

Within the niche market of model railroading, Bridgewerks serves the niche of large, G-Scale trains. The "G" stands for "garden." Built to a scale of 1:22:5, these models are more than twice the size of the old familiar Lionels and are typically set up outdoors as a landscaping feature.

"The engines are getting bigger and bigger," Sauerwald said. Garden railroaders "want more and more cars to be pulled and more and more engines running together."

That means they want more and more power, and that is what Bridgewerks provides. Sauerwald units run up to 30 amps -- that's enough for spot-welding, he said, but he's had a customer ask for 50.

"They want to pull more than the next guy."

Bridgewerks is a model-railroad business, but inside its nondescript building on the downtown fringe you won't find much in the way of trains. There is an operational oval of track upstairs, with a hefty scale model of a Norfolk & Western steam engine; but the space is dominated by steel casings, electrical components, machine tools and bundles of packing boxes.

Sauerwald is not a from-childhood train buff. He's an electrical engineer with a from-childhood fascination with gadgets and an entrepreneurial bent. About 15 years ago, he set out to build a bridge for the family train set that came out at Thanksgiving and went back into storage at New Year's. By the time he finished, he realized there could be a business in model bridges. Thus Bridgewerks was begun in his garage.

Then, a friend asked Sauerwald if he could fix the transformer for the model railroad the friend ran in his garden.

"I opened it up," Sauerwald said, "and I tell you, it was awful ... like a car with the fender dragging.

"I said, 'This is crazy. Somebody's got to build one better.' And it took off."

Since then, Bridgewerks has sold off its bridge division to concentrate on power. Sauerwald said about 120 retailers around the country carry his power supplies, power controllers and accessories.

His products come with a five-year warranty, but he said he's never charged for a repair or replacement no matter the product's age.

If the transformer that comes with a train set is a Chevrolet, said Dick Sossomon of the Triangle-based N.C. Garden Railroad Society, and the typical hobbyist's model a Toyota, then a Bridgewerks is the Lexus.

"They're expensive," he said. "They're heavy-duty, they're well made. ... If I had the money, I'd buy them."