Blaine Readler deliberately left his TV on as he headed out the door one night. "Cheap home security," he thought.

He figured that most burglars take the path of least resistance and avoid breaking into a home where a flickering TV usually signals that someone is home.

When he casually mentioned it in a conversation with fellow electrical engineer Rein Teder the next day, Teder set out to replicate the flickering with a computer program that did the same thing — but with less energy usage and wear and tear on an expensive HDTV.

The resulting product from Hydreon Corp. in Eden Prairie is a cupcake-sized device that mimics the flickering scene changes, color shifts and on-screen motion of a television.

"I wanted FakeTV to be realistic but not more active than regular TV," Teder said. His inspiration to copy programming that's bright and active was the animated movie "The Incredibles."

"I really like the movie. It's bright, colorful and dynamic with lots of chase scenes and zam powie," he said. "It fit my purposes perfectly."

Residents also can get peace of mind with a security system, deadbolts and a guard dog, but Teder's device requires no professional installation or pooper scooper.

To operate the device, plug it in and place it near a window where the flickering can be seen, but not the unit. At dusk it begins silently flashing for two or four hours, depending on the chosen setting. With its LED bulbs, it uses no more energy than a night light, about 50 to 100 times less energy than a flat-screen TV.

Teder has sold more than 200,000 units since 2008, but in the past couple of years customers started asking for a brighter device to match today's larger, brighter flat-screens.

The just released FTV-11 device ($40) is three times brighter than the original. It simulates a 40-inch TV compared with the original model ($30), which replicates a 27-inch.

Ron from Columbus, Ohio, a FakeTV user who asked not to be identified by last name to keep burglars at bay, said he didn't have the money for a security system, which can cost $500 to $2,500 to install and $30 to $50 per month for monitoring.

Instead, he bought FakeTV two years ago and hasn't had a break-in since. "But I also have re­inforced hinges and deadbolts and leave outside lights on to be safe," he said.

Cold weather also keeps some burglars at bay. Home break-ins increase during warmer months. "Residents start leaving windows and doors open, and more people are out of town on vacation," said Minneapolis Police Sgt. Stephen McCarty.

Rowena Holmes, a crime prevention specialist with the Minneapolis Police Department's Fourth Precinct, calls FakeTV a reasonable deterrent but said it shouldn't take the place of other actions. "Put several lights on timers and ask trusted neighbors to keep an eye out," she said.

The company doesn't claim that FakeTV will prevent burglaries. "We're careful not to ascribe magic powers to it," Teder said. "But we do hear from people who say their neighbors were robbed on each side of them and [the robbers] left their house alone."

To be on the safe side, the company has more burglary prevention tips at www.faketv.com.

The "research" that went into the product sounds like the ultimate project for any slacker inventor — watching a lot of TV. But Teder wasn't viewing the screen as much as the reflection on the walls.

An electrical engineer, he said FakeTV is the easiest thing he's ever invented. He is the author of 23 patents, including rain-sensing windshield wipers, which sell about 10 million units per year.

For now, he's concentrating on growing sales of FakeTV, which have doubled in the past two years. The small company is staffed with engineers but no marketers. That leaves Teder to be the pitchman, including a short spot on QVC in 2008. "We sold over 1,000 in five minutes and I thought we were doing really well, but the people at QVC were saying, 'We've got to do a lot better than that,' " Teder said.

Teder is leaving most of the marketing to his customers. "Referrals are still our biggest source," he said.

John Ewoldt • 612-673-7633