TAMPA — Checkers Drive-In Restaurants, which operates about 800 Checkers and Rally's locations, is being sold to Sentinel Capital Partners.Checkers announced that its private equity ownership group, Wellspring Capital Management, has entered an agreement to sell the company to Sentinel Capital Partners, a New York-based private equity firm. The terms of the stock purchase agreement were not disclosed.Wellspring put Checkers up for sale in 2012 after acquiring the company in 2006.In December, Sentinel Capital Partners bought Power Products, a Wisconsin-based electrical products company, for $258 million. It also owns Pizza Hut stores in southern California and Taco Bell locations in Minnesota.