# 12.6 v - 2a Transformer question

#### SO$hocking Joined Jan 1, 2012 4 I made a hot wire foam cutter with Radio Shack 12.6v-2a transformer, single pole dimmer switch and a guitar string. Q: Do I really need a fuse box? Do I need to hook the black middle wire on the transformer up? Will I blow this transformer with full dimmer on? Thanks. I'm new here and really like this forum already!! ps. sorry about my scematic pic. Transformer specs are wrong on it. #### Attachments • 22.1 KB Views: 43 #### SgtWookie Joined Jul 17, 2007 22,210 It would be a good idea to put a fuse in the mains side, in case there is a fault in the transformer. No, you don't need to connect the center tap. As far as the transformer burning up if you turn the dimmer all the way up - hard to say, as we have no clue how much resistance your guitar string has. I think they are generally a type of stainless steel, but resistance would depend upon length, diameter, how much it's corroded, etc. If you add a slow-blow fuse on the secondary to, say, 1.5x the transformer's rating, that should take care of it. Thread Starter #### SO$hocking

Joined Jan 1, 2012
4
Its a 16 gauge guitar string(i think it refers to thousands of an inch).
21" long
I don't have access to a slow burn fuse right now(nor any fuse), but i want to cut foam. BADLY!!!
Think I can risk it without a fuse for a little while?

#### bountyhunter

Joined Sep 7, 2009
2,512
If the transformer load is a guitar string, you are probably severely overloading the transformer and exceeding the current rating. An easy way to tell is stick a series Amp meter in and see the current.