Power supply always a problem

In this experiment we design use an alternating current (AC) power supply which can supply at least 3 ampere alternating current. At the first we try to contact Laboratory teachers to help us like before the holiday agreed upon, but in the lab they say can not give us. So we need think about way, after laboratory Equipment arrival there is an new problem in our project. Finally, we find a student who is in Year3 use alternating current power supply in his final project, we try to contact he and borrow the AC power supply, and today of afternoon we are in the lab to try to debugging to 3 A, in the test we try different resistance,  and burned the fuse in the power supply.Fortunately, we use 20 100Ω resistance parallel connection to finish our alternating current (AC) power supply.

AC power supply(15V)

parallel connection 20 100Ω resistances