# 12 volt circuit really basic question

#### obsessmuch

Joined Apr 16, 2007
1
Hi I have a super basic question. I have a 12 volt @ 4A power supply running a device. i need to power a second device from this power suply that only requires 12 v @ 100ma how do i reduce that down?

#### recca02

Joined Apr 2, 2007
1,214
well isnt it the case that circuits takes the req amount of current if u supply
specified voltage?

#### Eddy Kurent

Joined Apr 9, 2007
18
Your second circuit will draw only the amount of current it needs to operate.

#### John Luciani

Joined Apr 3, 2007
477
Hi I have a super basic question. I have a 12 volt @ 4A power supply running a device. i need to power a second device from this power suply that only requires 12 v @ 100ma how do i reduce that down?
Your ciruit will only draw the current it requires (I=V/R).

If your 100mA circuit develops a fault it can draw the full 4A from the power supply.
A fuse between the power supply and the 100mA circuit would be a good precaution.

(* jcl *)

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www.luciani.org

#### mozikluv

Joined Jan 22, 2004
1,437
how about a current limiter along the way?

moz