I have a 28V-0-28V, 7Amps centre tapped transformer to supply voltage to my load. Load will be a cell (plates are connected in both series and parralel) used in Chlorinator. I have a voltage regulator L7805CV. The link is below. [http://www.farnell.com/datasheets/2307057.pdf?_ga=2.224828637.639084130.1536017950-602646683.1536017950]
What I want is to use the same centre tapped transformer for the voltage regulator to get 5V. From the datasheet I found that Vi for regulator has to be around 10V to get Vout 5V. But the transformer is rated at 28V-0-28V. How can I drop voltage after Bridge rectifier but before feeding on to voltage regulator, Vin?