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.

Any ideas? Thanks.

 

Look at...

http://webook.fset.de/20091999PHCHO/DATASHEETS/317.htm

With the use of pass transistors 2A is easily obtained at minimum cost.

 

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?

 

Somehow "output 0 volts" sounds like a contradiction :roll:

 

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.

 

Hey,

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.

Steve

 

Yeah that would be cool.

rmjjensen@aol.com

Thanks.

 

include me pls thanks

droid@scihi.cjb.net

 

If you don't mind, can you attach the file with the post over here so that everyone can access it.

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"There is no way to peace, peace is the way!"

 

The key: an additional negative supply,equal with reference. With these solution any regulator can go to 0V.