V+ V- in electronic schematic: what is the meaning?

Other Hardware General Electronics
1

Hi all.

I was looking for a diagram showing the construction of a "Galvanic Skin Response Sensor",
and I bumped into this schematic:

http://www.element14.com/community/groups/pumping-station-one/blog/2011/05/08/ouch-sensing-galvanic-skin-response-gsr

It is the first time that I see the symbol "V-" beside the symbol "V+" .
I was wondering if, in this specific case, this is equal to GND, give that I cannot find GNd anywhere.
Thanks
Valerio

2

The V+ and V- is positive supply for the circuit and V- is ground.

3

valerio_sperati:
Hi all.

I was looking for a diagram showing the construction of a "Galvanic Skin Response Sensor",
and I bumped into this schematic:

http://www.element14.com/community/groups/pumping-station-one/blog/2011/05/08/ouch-sensing-galvanic-skin-response-gsr

It is the first time that I see the symbol "V-" beside the symbol "V+" .
I was wondering if, in this specific case, this is equal to GND, give that I cannot find GNd anywhere.
Thanks
Valerio

+V connects to the (+) Terminal of the 9 Volt Battery.
-V connects to the (-) Terminal of the 9 Volt Battery.

Technically, there is no "ground" in this circuit since it is a "floating" design.

NOTE:
The author did not use a Power Supply that would connect to the AC wall outlet.
Be very careful when connecting any circuit to a human being.