Find the turns ratio

 

A linear DC power supply system is to be designed to support the different power requirements of the subsystems comprising the electronic lecture theatre environmental control system. The system power requirements are difficult to determine before the design and implementation of the subsystem prototypes are complete. The power supply is to be driven by the mains wall outlet. A multi-output transformer with a 1 A secondary current rating is available from the School of EIE and is to be used in the power supply design - its secondary voltages are 3, 6, 9, 12, 15 and 18 Vrms. The power supply must use a bridge rectifier constructed from four discrete diodes. The LPS design is to have three outlets : 5 V DC at 200 mA, 19 V DC at 300 mA and 12 V DC at 400 mA. Furthermore, the LPS is to have a proper DC ground.