Lab power supply unit

[Dr.EM]

At my college, they have these units that output (fixed) 5v (for logic) and also a -15 : 0 : +15v supply (for op-amps and such). We use them with breadboards.

I've searched around, and can't find anything much like it. At Maplin, they have high current 13.5v supplies, for CB radio, and also high stability, very expensive lab supplies. The ones we use arn't either, and they don't look very expensive.

Could anyone help me find one :?

 

[2PAC Mafia]

Hello,

there are a lot of power supplies with 2 variable outputs from 0 to 30V and fix 5V or 3,3V for digital signals. With the variable ones you can create the negative voltage connecting positive of one of them to negative of the other then you will get between this connection point and the other positive a maximum of +30V and to the other negative a maximum of -30V. You create a reference ground between that points, so I think is better if the outputs are isolated between them.

Another option is to build yourself the power supply unit, if you don´t need a lot of current it´s quite easy to make it.

 

[bonxer]

**broken link removed**

Buy two of those, set them both to 12, and connect them like 2PM said, although this will get you +12 and -12, as opposed to 15's.

Supply 1's black output will connect directly to Supply 2's red output. That will be your common ground. Supply 1's red output will be your +12, and Supply 2's black output will be your -12.

 

[Dr.EM]

Yeah, I never thought of that, cheers. Though, living in the UK sure makes it more awkward to get anything.

I had considered building my own, but after that one "mains experience" :shock: