As title really.

Wondering if ok to use a rocker switch that specifies AC 250V 1A for a 5V 4A power supply plug? It's for a usb hub.

 

Hello,

Have a look at the datasheet of the rocker.
That should also give the DC properties.

Bertus

 

Don't you think the switch will melt with a current that is 4 times higher than its rating?

 

Switches are from eBay. It doesn't say anything about DC ratings.

https://www.ebay.co.uk/itm/264393759247

 

I wouldn't do it. Aside from the issue of severely overloading the contacts with 4X their rated current, there's the issue of contact resistance and voltage drop: running on only 5 volts, your application is likely going to be VERY sensitive to any voltage drop across the contacts-- and that voltage drop is likely to be very substantial due to the high current.

Buy a proper switch meant for low-voltage, high-current service.

And don't get it from Ebay.

 

I wouldn't do it. Aside from the issue of severely overloading the contacts with 4X their rated current, there's the issue of contact resistance and voltage drop: running on only 5 volts, your application is likely going to be VERY sensitive to any voltage drop across the contacts-- and that voltage drop is likely to be very substantial due to the high current.

Buy a proper switch meant for low-voltage, high-current service.

And don't get it from Ebay.

Ok will do. Any in particular you recommend?

 

Switches are from eBay. It doesn't say anything about DC ratings.

https://www.ebay.co.uk/itm/264393759247

ebay sells cheap junk. They make extra profit by making the decimal point so small that you don't see that it is actually 0.1A and is not 1A.

1A AC will heat a resistance (the switch) exactly the same amount as 1A DC. 4A will melt it.

 

Hello,

Have a look at the rocker switches from C&K.

Bertus

 

Ok will do. Any in particular you recommend?

No. Just buy from a reputable manufacturer through a reputable electronics component distributor. Buy a switch rated for AT LEAST twice the maximum current you expect it to handle.

 

Wondering if ok to use a rocker switch that specifies AC 250V 1A for a 5V 4A power supply plug?

You need to consult the datasheet.

I looked at a datasheet for D4 Cherry switches. They only gave a DC rating for the last one:

And the DC current capability was lower.

This is from C&K:

 

What is not mentioned is if the switch is in the mains power to that 5 volt supply, or if you are wanting to switch the 5 volts line. There is a very big difference. It should be OK switching the mains power, not the 5 volts line.

 

What is not mentioned is if the switch is in the mains power to that 5 volt supply, or if you are wanting to switch the 5 volts line. There is a very big difference. It should be OK switching the mains power, not the 5 volts line.

It was for the 5v line. Have selected a 6A inline rocker switch now. Thanks all.

 

It is quite unusual to switch the DC power line for a hub. Why do it? That is a puzzle to me. Generally the hub stays on with the computer serving it.

 

I put a switch on the hubs psu as it was drawing 2 watts even without anything plugged in to the usb ports, compared to 0.1 watts when PSUs switch is off so it's to save electricity (I'm on a meter)!

The hub uses the pc for low power stuff like flash drives or ssds. If I need to plug in a mechanical drive, I can just flip switch to provide more power.