# Power switch dimension question

#### Kristian Jörg

Joined Jun 9, 2016
3
Need a power switch for a mobile Raspberry Pi application, so it will switch on/off 5V at a max amperage of 2.5A. Looking at a specific item, it is rated 50V, 0.5A and used by another project. How are these items rated really? Could it be used in a low-voltage application? Looking at the amount of Watts, 50V x 0.5A = 25W.
5V at 2.5A = 12.5W.

So, this is the question. Can a switch rated for a higher voltage be used for a lower voltage application and suffice, even though the amperage is not within spec?

Joined Mar 10, 2018
4,057
The amperage is "usually" an indication of contact size of the actual
switch contacts. So no to using too small rated current.

In general - http://www.tpub.com/neets/book3/9f.htm

Regards, Dana.

#### Kristian Jörg

Joined Jun 9, 2016
3
Thanks. According top that document BOTH voltage and current ratings need to be met. I can only conclude that the part used in the GamePi project above is no good then.