Thread: Need some help for a touch switch

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I'm going to have lights and such running, and when the visitor touches a shepherd's staff, I want it to kill the lights in the room.

Problem is, I don't know how to configure a touch switch on this staff to make this work. Maybe I could put a small plate on each side and have them grab it, closing the contacts, and wire this to a relay. What do you guys say?

Are they going to raise or move the staff or just touch it? What is the diameter of the staff?
I think I would try to put a sub-miniture momentery switch in it and have that drop out a relay to shut off the lights. Just a thought......

They will just grasp it. I'm concerned that they wouldn't necessarily hit the switch if it were pushbutton.

Originally Posted by lucynt

They will just grasp it. I'm concerned that they wouldn't necessarily hit the switch if it were pushbutton.

Have you made the staff yet ? what about possibly incorporating a touch lamp into the equation ?

Switch Control with Touch-Sensitive Input

Howstuffworks

PAiA - K10 - Touch Switch/Plate, Building Block Kits, K10
PAiA - K137 Touch Switch Relay With Timer, Building Block Kits, K137

No, nothing has been built yet, still planning. Not a bad idea with the touch lamp, but I was hoping I could just apply the basic components to a prop I built. I've just never worked with any sort of touch switch solutions, via relays, or kits.

@ The Pod

Dude, I've seen a few diagrams such as this, but I am not very well versed in reading such a schematic. Maybe I should just opt for a kit somewhere.

You can use a Darlington transistor and a couple of resistors to make a touch switch. It's a very simple circuit. I'd say your bigger issue is how to lock out the transistor switch after the first touch. That will likely require some kind of timer. A simple capacitor discharge timer would do the job by using a small relay to disable the Darlington circuit for a short time.

Here's a link to the Darlington circuit:
Transistor Circuits
Scroll down to "Darlington pair".

So, roughly, what value of transistors would I need? Furthermore, I'm not sure of how to wire this based on the schematic. (i'm not familiar with most of the symbols).

And would this function like a momentary switch? That's what I'm after.

You could use a MPSA13 Darlington for this circuit. All the parts you need are available at places like All Electronics, Jameco etc. I could whomp up a quick circuit for you in the next couple of days, if that would help. I'm pretty sure this could be configured as a momentary switch.