This paper is an advance experiment, developed to enable us appreciate the performance of the semiconductor diode as a rectifying device, especially as a full wave rectifier. It entire process includes the bridge rectifier and a regulation circuit to provide a standard d.c power supply system. The experiment is conducted in stages, using three different stepdown transformers of 240V/15V with power ratings of 500VA, 1000VA and 1500VA respectively, to build the regulated d.c power supply on a breadboard. Load test were carried on each circuit with load resistance of between 1200omhs to 20ohms. For each circuit, values of load voltage and load current were taken and recorded. The load test enables us to observe the maximum load current each transformer is capable of handling without its output voltage dropping appreciably. The result of this test is a factor in determining the choice of transformers used in the d.c power supply unit of electronic equipment, instruments and appliances.