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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: stevetoney on March 18, 2013, 08:26:15 AM

Title: Newb Preamp Question: Is Negative = Ground in a DC battery powered circuit?
Post by: stevetoney on March 18, 2013, 08:26:15 AM
I've broken into enough components now to be dangerous, but my learning curve is still nearly vertical.  I have a newb question about circuit design...

In a battery powered preamp circuit (IOW, it's DC powered), is routing to the negative battery terminal sufficient to complete the electrical circuit or is it also necessary to connect the circuit to the metal case of the preamp?  The reason I ask this question is in recently looking at some circuit diagrams for battery powered preamps, they typically show at least one ground path, but sometimes they have several (although I do understand that all of those may end up being connected at the same point).  They never seem to be without the ground path, but wouldn't current flow through the circuit just by connecting to negative?

A correlary question...(it's OK if anyone wants to put this in the 'stupid' category)...when we have battery powered gear that's grounded to the case, a) why don't we get shocked when we touch the case, and b) why isn't there a shock say if the case of my preamp contacts the case of another piece of gear in my bag?
Title: Re: Newb Preamp Question: Is Negative = Ground in a DC battery powered circuit?
Post by: stevetoney on March 18, 2013, 12:55:43 PM
Thanks for the response Jon.  I was hoping you'd see my questions.

Also, thanks for the 'do not lick' advice.  Course now that you've put a thought in my mind that I'd never had before and probably never would have had otherwise...   ;)
Title: Re: Newb Preamp Question: Is Negative = Ground in a DC battery powered circuit?
Post by: Chuck on March 18, 2013, 03:33:02 PM
I still "lick" 9v batteries to see if they are dead when I don't have a DVM with me.  :crazy:
Title: Re: Newb Preamp Question: Is Negative = Ground in a DC battery powered circuit?
Post by: twatts (pants are so over-rated...) on March 18, 2013, 04:18:36 PM
You are OK licking a tinybox

Good advice...

Terry
Title: Re: Newb Preamp Question: Is Negative = Ground in a DC battery powered circuit?
Post by: stevetoney on March 18, 2013, 06:20:57 PM
You are OK licking a tinybox

Good advice...

Terry

More research necessary. 

But really, Jon, I didn't realize you'd switched and became a hygenist.