How do you calculate DC voltage?

GoGoBear's picture


Joined: Apr 16, 2021

Replies: 0
How do you calculate DC voltage?
April 16, 2021 - 11:51am

I have several lights that operate on AAA batteries. I want to stop using batteries and plug in a DC power supply to power these. Each light uses 3xAAA batteries so that’s 4.5v. These are not equipped to be operated by a power supply, so I'd have to solder wires to battery terminals. 

if I connect these in a way that 2 wires come out of the power supply and distributes to each light and assuming I have 10 lights in total, should my power supply output 4.5v or 45v?


A link to a rough diagram of how the wiring would be below. Note that individual lights can and most likely will connect in different parts of the main wire coming out of the power supply.



Appreciate all your responses!




Sourav Gupta's picture


Joined: Feb 12, 2018

Replies: 627

If the light has forward voltage of 4.5V, as per diagram the total voltage is 4.5V since all are parallel. But the current will be multipied by the light count.