Power supply output

[woodbutcher]

I was directed to this site when I asked, How to test a power supply. In particular it is not for a computer but for a CNC controller board, and I need to test it to see what the output is. It has a connection for 115 volts going in and it has several (post) connections going out but it doesn't say what voltage they are. How do I check this out? Thanks for any help.

 

[Guest]

I would buy a medium priced digital multimeter -- probably the most useful tool for anyone who plays with electronics.

 

[woodbutcher]

Mr Moderator,
I guess I should have been more specific. I was looking for maybe some tips on how to use my multimeter to check out my undocumented power supply. 1. Is it AC or DC output, How do I check? 2. If it has a 5amp fuse on the input side is that the max amperage available on the output side, How do I check? Apparently these are techniques that I should already know. Maybe you could direct me to a site that could educate me on the subject of trouble shooting to determine what type of power supply I actually have.

 

[Guest]

If you have as analog (needle type) multimeter and select DC voltage on it and then the voltage you apply turns out to be AC, the needle will wag.

A 5 amp fuse on the input side suggests that is to protect the input side. It probably has nothing to do with output.

In USA I would direct you to Radio Shack who used to do some quite good basic guides to electronics (they closed their European stores some years ago).

 

[woodbutcher]

Best answer selected by woodbutcher.

 

[Guest]

"A 5 amp fuse on the input side suggests that is to protect the input side. It probably has nothing to do with output."

On reflection that isn't accurate (though it has no bearing on your question). A fuse on the input side is there to blow if there's a serious failure within the device -- to avoid furter damage to the device, to prevent fire and to protect house wiring. Five amp fuse rating reflects the amount of power drawn (less than 5amps, obviously).