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From: Don Y <blockedofcourse@foo.invalid>
Newsgroups: sci.electronics.design
Subject: Re: mountable power ports
Date: Wed, 26 Mar 2025 14:11:55 -0700
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On 3/26/2025 1:50 PM, Liz Tuddenham wrote:
> Don Y <blockedofcourse@foo.invalid> wrote:
> 
>> On 3/26/2025 8:56 AM, Christopher Howard wrote:
>>> Hi, my project box is a large tin cookie box. I need to bring in +15V,
>>> -15V, and GND lines from my external bipolar power supply. (I was
>>> thinking I would have a separate bolt for the chassis ground, which
>>> would go off to a big ground bus bar near my workbench.) For the three
>>> lines from the power supply, I am wondering what would be the best (but
>>> economical) choice for a power connector to mount into the side of the
>>> project box. Something that sounded appealing was the spring speaker
>>> terminal clips I see on Amazon, but the downside there is they only come
>>> in pairs of two or four, rather than three, and they are color coded
>>> red/black which does not quite make sense here. I am inclined to leave
>>> the wires on the power supply itself bare on the end, rather than
>>> attaching some specialty connector to those.
>>
>> There's always the old benchtop standard of binding posts.
>   
> I second this.
> 
> Screw pillars with 4mm banana sockets in the centre.  Available in a
> wide range of colours, rated to 500v and 10 amps.  Easy to fit, easy to
> plug-up and easy to see what you are doing so you don't make silly (and
> expensive) mistakes.

Though if you are sloppy and let wire strands (think: non solid
conductors) bridge the gap to the other post -- or, metallic items
on the desktop -- you can be in for an unexpected surprise (esp
if the power supply has any muscle)

> Use matching colour-coded wires and plugs, so there is even less chance
> of a screw-up.

There are two (primary) downsides:
- they are physically large
- they require deliberation when making (breaking!) connections
   (and, diligence to ensure the connection is SECURELY made)

If sequencing of supplies is an issue, then one would have to
impose self-discipline in how the attachments (and removals)
were made.

OTOH, there is no possibility of one signal momentarily connecting
to an unintended signal on entry/removal as is the case in phone plugs.

But, the added value is that one can dangle pigtails from them
to daisy-chain the supply to other devices without having to
fabricate a special cable.  (this is when I drag out benchtop
supplies instead of relying on "bricks" and their ilk.