switch idea

[antek]

I need to build a switch that normally would be off and when it will be pull to on position it would stay on, even if the switch would be pull to off position.

I mean the position of the switch is off and when for first time it would be switched to on it would stay on all the time,

sorry for my english.

 

[panic mode]

it's called latch. what is the power source and what is the load?
did you think of way of turning it off?

 

[antek]

thanks for replay

I need to build a machine (I belive it's called ruby golberg) And my task is to make some circuit that will include few switches that will be normally off and when the ball hit the switch it will switched to on and it will stay on all the time, so I relly don't have to find any way to turn it off jus disconect from the battery.
the switch would be conected to LED so as the ball move foward the next LED would switch to on and so on.

 

[crashsite]

Ruby Goldberg

I need to build a machine (I belive it's called ruby golberg)

Ha ha...actually, it's called a, Rube Goldberg (named for a cartooist of the 1930s and 1940s who would draw devices that did simple tasks in the most complex way he could imagine).

To make a true Rube Goldberg device I'd be inclined to make the switch contacts connect directly across a car battery so the contact fuse shut when the switch is turned on. They will then stay closed even if the power is removed.

For something a little less dramatic, you can use a latching relay (basically what the previous poster was referring to) where the switch energizes a relay coil and when the contacts close they keep the relay coil energized.

 

[Leftyretro]

You could build some kind of mechanical latch that keeps the contacts closed once they are activated or just use an inexpensive DPDT relay as wired attached. This will not unlatch unless you remove battery power but it would be easy to add a normal closed reset switch in the battery lead.

Good luck

Lefty