Power Switch

Other Hardware General Electronics
1

I want to have a power switch on a PCB I am making, but all of the cheap ones have a rated current of less than 300mA. This is not enough for my project. Has anyone seen any TRUE, but small (I don't want a big rocker switch) switch with a current of an amp or so? Or should I use a switch/transistor arrangement to switch the load?

Thanks!
baum

2

would suggest a FET rather than a transistor. Simpler control and much less in-line resistance

3

Can I get FETs in the NPN transistor package? standard pkg is large.

4

how about this one? http://www.allelectronics.com/make-a-store/item/SWS-10/S.P.D.T.-KNIFE-SWITCH//1.html

While you gave a current specification you didn't mention physical size and stype of switch you want. Certainly there are many switches out there that would meet your needs if you can give more details of what you want.

Lefty

5

You might want to check out this product matrix:

6

physical size and stype of switch

I want an SPDT or SPST switch that is very small, about 1/2 inch long. (like the one I mentioned earlier).

This one (from James)

looks nice, it can handle 6A (not that I need that much). I'll see if digikey has it.

Thanks!
baum

7

Can I get FETs in the NPN transistor package?

NPN is a transistor type, not a package.

8

I know. But in that similar package.

9

What "similar" package?
You mean like a 2N3055 NPN (TO-3), or a 2N2222 NPN (TO-92(?)) or... ?

10

How about this?

2.5A@10VDC

If I can find the eagle footprint for it, maybe I'll use that...

11

Have you got 10V to drive it with?

12

I'll be using 5V.

13

Can't see the correct graph, but 5V sounds a bit low.
Can you cope with the higher restistance?

14

Not really.

I'll start again with what I want to do, in greater detail.

I am making a PCB for a microcontroller, which is powered by a DC barrel jack. I want a switch on some sort so that I can turn the micro on and off w/ out unplugging the jack. From the switch, the power is feed to a 7805, which powers the micro. I want the board to be small, so a transistor/switch may not be the best idea. I'll keep looking for switches, I guess.

15

Given that you need a switch anyway there's little point in having a transistor as well.

Was the C&K switch linked to above not suitable?

Have a look at

Rob

16

That one was good. I'll look if dkey has it.