### Author Topic: \$50 power  (Read 1507 times)

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#### robaker

• Jr. Member
• Posts: 16
##### \$50 power
« on: March 06, 2010, 04:17:03 AM »
the grounds of 4,8V and 9v are shared...
Is sharing the ground of 4.8V and 9V battery necessary  ?
If we seperate the grounds of both 4.8 and 9v also , is there any risk?
if not ,how does one know ?

#### chelmi

• Supreme Robot
• Posts: 496
##### Re: \$50 power
« Reply #1 on: March 06, 2010, 08:54:20 AM »
they have to be connected. Voltage is not an absolute value, you need a common ground.

#### robaker

• Jr. Member
• Posts: 16
##### Re: \$50 power
« Reply #2 on: March 07, 2010, 02:03:16 AM »
--Voltage is not an absolute value, you need a common ground.--
?? plz explain this line...

#### SmAsH

• Supreme Robot
• Posts: 3,959
• SoR's Locale Electronics Nut.
##### Re: \$50 power
« Reply #3 on: March 07, 2010, 02:13:46 AM »
I don't understand the first part but, keep the grounds connected, you need this.
Howdy

#### cyberfish

• Robot Overlord
• Posts: 163
##### Re: \$50 power
« Reply #4 on: March 07, 2010, 02:39:43 AM »
Voltage = potential DIFFERENCE - difference in potential energy between 2 points.

Without a common ground, the 2 differences won't do much. You will have essentially 2 separate circuits.

In short, they have to be connected together.