Hey ...I'm new here and also an electrical engineering student.
One of my projects is to build a power supply that takes 120V a/c and converts it to a variable output of + and - 15V DC. It must be able to output 2A at both the positive and negative supplies.
I've got the whole converting of A/C -> DC down, but I'm not sure how to get a variable 15V output that can put out 2A of current. Any voltage regulators I've found either aren't variable, or don't output enough current.
That helps a lot with the pass transistor. One of my other requirements is that i have to be able to output 0 volts. I don't think i can do that with the LM317. Won't it maintain at least 1.25Volts on the output?
Well, my professor wants that as you adjust the voltage through the POT, you can reach 0 volts when the POT is all the way down. Basically, acheive no voltage output without switching the power supply off.
I can send you a drawing of a schematic that will do this. You will need to use the K-type package of the LM317.. It is on disk, but my A drive is broken. I can do this either at school or at my girlfriend's house. It is in a dwg format, so I hope you have something that can read it.
If this is okay, please leave your email and I will send it tommorow some time.