Society of Robots - Robot Forum

Electronics => Electronics => Topic started by: SeagullOne on February 18, 2009, 05:26:16 PM

Title: Switch opened or closed?
Post by: SeagullOne on February 18, 2009, 05:26:16 PM

Okay, I bought this switch from RadioShack and I want to use it as a kill switch on my robot:

http://www.radioshack.com/product/index.jsp?productId=3042775 (http://www.radioshack.com/product/index.jsp?productId=3042775)

The problem is, I can't tell what the "On" and "Off" toggles are. That meaning, I can't tell what opens and what closes the circuit... ???

All I see are the numbers 1, 2, and 3 on the side. But I'm having trouble deciphering what that means...can anyone help me out please?

Title: Re: Switch opened or closed?
Post by: Webbot on February 18, 2009, 05:32:19 PM

Check with a meter - but you'll probably find that your switch is wired like this:

             --------- out
 in ____/

            ---------- (unconnected)

So the middle connector is for (in), and then one of the outer connectors will be (out) and the other (unconnected).
Connect an ohm meter to the middle pin and one of the outer pins. Try flicking the switch to see when resistance = 0. If nothing happens:- change the meter to use the other outer pin connector. Flipping the switch should now change the reading.

EDIT: Could be a good tutorial for someone ie SPST, DPST, SPDT, DPDT, DIL/DIP, push to toggle, push to break, push to make switches etc etc. Voltage/current requirement. What is contact bounce and does it matter? How to overcome it in hardware/software.

Title: Re: Switch opened or closed?
Post by: SeagullOne on February 19, 2009, 02:30:41 PM

Thanks Webbot, but I can only seet two terminals at the bottom of the switch. There is no middle connector.  ???

Title: Re: Switch opened or closed?
Post by: chelmi on February 19, 2009, 02:37:25 PM

Quote from: SeagullOne on February 19, 2009, 02:30:41 PM

Thanks Webbot, but I can only seet two terminals at the bottom of the switch. There is no middle connector.  ???

Maybe I missed something, but if you have two pins then there is no question...

Title: Re: Switch opened or closed?
Post by: ed1380 on February 19, 2009, 02:39:27 PM

use a multimeter. if current flows through the switch its closed. remember and label that position. if it doesnt flow its "open" or "off"

Title: Re: Switch opened or closed?
Post by: Webbot on February 19, 2009, 02:51:21 PM

Quote from: SeagullOne on February 19, 2009, 02:30:41 PM

Thanks Webbot, but I can only seet two terminals at the bottom of the switch. There is no middle connector.  ???

Heres the image on the link you sent:-
(http://rsk.imageg.net/graphics/product_images/pRS1C-4563530w345.jpg)

This has a connector at the very top, one at the very bottom, and the 'middle' one which is just above the bottom one.

Title: Re: Switch opened or closed?
Post by: chelmi on February 19, 2009, 03:01:35 PM

Quote from: Webbot on February 19, 2009, 02:51:21 PM

This has a connector at the very top, one at the very bottom, and the 'middle' one which is just above the bottom one.

I think that what you see is the fake reflection of the switch. It is soooo fake that they didn't even bother to mirror the image. They just translated the original and added a gradient.
 :o What's the point on a technical picture? ...

Title: Re: Switch opened or closed?
Post by: SeagullOne on February 19, 2009, 04:00:58 PM

Thanks guys!

I'll just use a multimeter and see what I get (I think I should have thought of that in the first place though...)

Title: Re: Switch opened or closed?
Post by: SmAsH on February 20, 2009, 12:53:29 AM

you could just use a simple circuit and see when the led turns on?

Title: Re: Switch opened or closed?
Post by: SeagullOne on February 20, 2009, 11:20:38 PM

Okay!  :D

I wired a simple circuit with a small motor. As I said before, there are three numbers across the side of the switch: 1, 2, and 3. Apparently, when the lever is pulled toward the 1, the switch is open. When the lever is pulled to the 3, the switch closes and the motor spins. So now I know which is which.

Thanks, guys!