The invention is set for connecting L.E.D., bridging rectifier and AC/DC power transformer by using series connection method, also the main purpose is for saving energy and reducing the cost of electronic components. The first apparatus is built by first bridge rectifier, first L.E.D. group and first current-limiting resistor using the series connection method. The second apparatus is built by second bridge rectifier, second L.E.D. group and second current-limiting resistor using the series connection method. Then, finally the previous two apparatus will be connected each other by using parallel connection method to the AC/DC power source.