USB relay?

[lpcam]

I am looking for a relay controlled by UBS that is able to switch 300W on 48V.

 

[nbucska]

How many channels? DC or AC? Is the load inductive (motor)
Resistive ( heater ) or incandencent light?

Do you need inputs,too? how many ?



Plesae read FAQ240-1032
My WEB: <

http://geocities.com/nbucska/>

 

[nbucska]

try <

http://www.tamsinc.com>

Plesae read FAQ240-1032
My WEB: <

http://geocities.com/nbucska/>

 

[jraef]

Google is your friend.
I got 1.32 million hits on the search term "usb relay".
This outfit seems to have a number of power rating options.

http://www.j-works.com/

JRaef.com
"Engineers like to solve problems. If there are no problems handily available, they will create their own problems." Scott Adams
For the best use of Eng-Tips, please click here -> faq731-376

 

[lpcam]

The relay will be use to switch lights. Power will be 48V DC or 12V DC. I may need 1 input and 2-3 outputs

 

[nbucska]

Incandescent light bulb start with a large current
I have read somewhere that some bulds start with 14 times
higher current . This would be 88 Amperes !!!

You can use mech. relay or MOSFET -- no SCR,TRIAC or
bypolar transistor.


Plesae read FAQ240-1032
My WEB: <

http://geocities.com/nbucska/>

 

[jraef]

300W on 48V = 300VA with regards to an incandescent load. The positive temperature coefficient (hot-to-cold resistance ratio) of tungsten does mean a high inrush, but the duration is so short that it becomes not as important as you might think. Most contacts have a "making" capacity that is 6 times the rated continuous current capacity. So even if the inrush is 14 x 300VA = 4200VA, that only relates to the continuous rating being 700VA, so at 48V means <15A, which is still a lot on a basic relay that you will find in the USB relays I've seen, but not unattainable. They had 15A rated relays on that link I provided.