MINNEAPOLIS – To any parent who's argued with a child over shutting off a video game, John Morrissey's Game Dr Video Game Timer may sound like salvation.

Parents can set the $30 timer to limit game play to a specified number of minutes or hours a day. At the appointed time, the password-protected timer shuts off electricity to the game console, ending all arguments about playing for just five more minutes.

Morrissey, a 79-year-old Edina, Minn., inventor, figures there's large pent-up demand for his inexpensive and easy-to-use device. Some surveys suggest that half the parents of preteens and young teens worry that their kids spend too much time playing video games.

But Digital Innovations of Arlington Heights, Ill., the company that has just begun selling the GameDr, expects a more mixed reaction from the owners of 88 million U.S. video game consoles.

"There are moms who say they love this, and that they know 10 people who need one," said Kara Lineal, Digital Innovations' marketing director. "And there are gamers who say it's terrible and that parents should just monitor their kids."

Morrissey isn't the first entrepreneur to try to capitalize on parents' desire to curb screen time. Already, about half a dozen similar game timer units are sold online, and Microsoft includes one in its Xbox 360 console. None has generated much publicity.

"If parents are that concerned about what children are doing on home video game consoles, the chances are they don't have a console or have one with only games appropriate for their children's ages," said David Riley, director of corporate marketing at the NPD Group, a consumer product sales tracking firm in Port Washington, N.Y.

But Morrissey believes he can help parents and children find common ground.

"I have 11 grandchildren, and there are days when they use video games a little more than I would like and other days when they don't," he said. "We wanted this product to create a comfort zone for both parents and kids."

One reason the GameDr can help reduce the stress level between parent and child is that the timer becomes the "bad guy" limiting gaming time, not the parent, said Doug Swanson, Morrissey's son-in-law and president of consumer electronics at the sales representative firm Select Sales in Bloomington, Minn.

Given his age, it would be easy to pigeonhole GameDr's inventor as someone who pines for simpler times, before television came along and messed up everything.

But that's not Morrissey. He holds degrees in chemical and nuclear engineering, and in the 1960s he worked on nuclear rocket propulsion at NASA. Until retiring in the early 1990s, he was a SuperValu executive and board member.

"Video games are great," Morrissey said. "There is evidence that they improve the reflexes and the thinking process. But right now, for many parents, the option is all or nothing – they either let the kids play the video game or they take it away for two weeks."

And while his device may shut the console down, it gives the player some warning beeps a few minutes beforehand so a game in progress can be saved for later.

Because Morrissey knew little about how to have the Game Dr manufactured or marketed, he sold the invention to Digital Innovations, which will pay him a royalty on each unit purchased by consumers. The timer is being marketed under Digital Innovations' GameDr product line, which also includes kits to repair scratches in CDs or DVDs.