[sdiy] Question about earthing on power-one psus

[harrybissell]

The +s and -s teminals are sense terminals (like a differential amp, you need to hook
them BOTH up.  Wire the three terminals in the middle together.

Whether you want to tie protective EARTH ground to your circuit is your choice.
The frame of the power supply should be tied to earth ground, and probably your
circuit should be tied at some point as well... but perhaps through a resistor and/or
capacitor.

THAT is another story :^P

H^) harry

Julian wrote:

> Hello there,
>
> Using dual output power-ones, like the HBB-15 or HAA-15 etc. you get seven terminals,  which read across as:
>
> -out
> -s
>
> +s
> com
> -s
>
> +s
> +out
>
> Now on those that ive bought secondhand, the terminals have allways been jumpered into 3 groups, as ive kinda demonstrated above.
>
> Now the +/- out and +/-sense terminals i understand, but the middle group?  Why do i not just run the ground back to my mains lead
> ground?  Why is it necisary to run to this central group, and, excluding grounding the chassis for saftey reasons, why is there not
> a ground back from the psu?
>
> Thankyou,
>
> Julian - looking to improve the grounding of his modular.