Anyone Know How To Make A Touch Contact Switch?

[Scubabatdan]

Ok did some digging and came up with a wiring schematic that might make more sense based on what willyb and cybervex was talking about. This used the IRF8736PbF MOSFET chip Found here:
http://www.irf.com/product-info/datasheets/data/irf8736pbf.pdf

Here is the schematics I came up with, this make sense to you?
Dan

 

[Sir_Lawrence]

Ok did some digging and came up with a wiring schematic that might make more sense based on what willyb and cybervex was talking about. This used the IRF8736PbF MOSFET chip Found here:
http://www.irf.com/product-info/datasheets/data/irf8736pbf.pdf

Here is the schematics I came up with, this make sense to you?
Dan

This is great! Now, with this, must it be used with a regulator, and can it be used with all the voltage batteries I was talking about?

 

[Scubabatdan]

This is great! Now, with this, must it be used with a regulator, and can it be used with all the voltage batteries I was talking about?

Need someone else to chime in here, I have not tested if you push 3.7vdc through a voltage regulator if it will put out the same voltage. In theroy it should since it limits above the set point for the regulator.
Anyone else?
Dan

 

[Sir_Lawrence]

Ok did some digging and came up with a wiring schematic that might make more sense based on what willyb and cybervex was talking about. This used the IRF8736PbF MOSFET chip Found here:
http://www.irf.com/product-info/datasheets/data/irf8736pbf.pdf

Here is the schematics I came up with, this make sense to you?
Dan

Also, pin 1 and 6 supposed to touch or not?
With 3.7v and 6v, I wouldn't used a regulator... would that work?
With 6v and 7.2 I would use a regulator. Gives some options.

 

[Sir_Lawrence]

Does anyone have a link for the 4.7m surface mount resistor?
And what watt should I use?

 

[Scubabatdan]

Also, pin 1 and 6 supposed to touch or not?
With 3.7v and 6v, I wouldn't used a regulator... would that work?
With 6v and 7.2 I would use a regulator. Gives some options.

No there is no join dot, so they are seperate. Yes you could go to 6 volt with out a regulator.

4.7M Resistor Links, I am guessing 1/4 watt, that is all I am finding:
http://www.mouser.com/search/ProductDetail.aspx?R=30BJ250-4.7M

https://www.solarbotics.com/products/r4.7m/

http://www.bugnbots.com/productinfo.php?ID=68

Dan

 

[Sir_Lawrence]

No there is no join dot, so they are seperate. Yes you could go to 6 volt with out a regulator.

4.7M Resistor Links, I am guessing 1/4 watt, that is all I am finding:
30BJ250-4.7M Xicon Carbon Composition Resistors

https://www.solarbotics.com/products/r4.7m/

Bugnbots - Shopping

Dan

Thank you again. You have been so much help. Oh, and the tobacco flavoring you helped me with still tastes great! I also ordered the flavorings from the tobacco flavoring company. It worked out well!

 

[Scubabatdan]

Thank you again. You have been so much help. Oh, and the tobacco flavoring you helped me with still tastes great! I also ordered the flavorings from the tobacco flavoring company. It worked out well!

LOL I just can't stop....

Here is a better layout for the Mosfet version:
Dan

 

[Sir_Lawrence]

LOL I just can't stop....

Here is a better layout for the Mosfet version:
Dan

I know... I can't stop either! Like I stated, it's almost like my new addiction! What you are doing is great... even put a pc board template to use! Thank you.

 

[Sir_Lawrence]

LOL I just can't stop....

Here is a better layout for the Mosfet version:
Dan

I just had the design team at DigiKey.com check this all out, and told them not to broadcast it all over the web. They said this is a good design and it should work well. They said using 1/4 watt resistors should be ok. Again, thank you for all of your help.

 

[Sir_Lawrence]

LOL I just can't stop....

Here is a better layout for the Mosfet version:
Dan

What is a good program to design and layout printed circuit boards?

 

[Scubabatdan]

What is a good program to design and layout printed circuit boards?

Microsoft Visio for the circuit design, and Express PCB for the circuit board design found here:
ExpressPCB - Free PCB layout and schematic software

Once you design the circuit you can send it to the company for a price quote and manufacturing.
Dan

 

[Scubabatdan]

Here is a quick diagram I did on it:
Dan

 

[Sir_Lawrence]

Here is a quick diagram I did on it:
Dan

Thanks... but I don't understand. You know how well I am at electronics! Isn't the LM7805 another 5v regulator? If it is, could I use the one in my diagram? Could you show how to make that into a printed circuit board like you did the other?
The one I came up with that I sent you, did I do that right?
Thanks

 

[Scubabatdan]

Thanks... but I don't understand. You know how well I am at electronics! Isn't the LM7805 another 5v regulator? If it is, could I use the one in my diagram? Could you show how to make that into a printed circuit board like you did the other?
The one I came up with that I sent you, did I do that right?
Thanks

Yes, and Yes, your diagram you sent me looks good, check your PM. I have answered you there. I will make the schematics for you tomarrow, I am going to bed now LOL
Dan

 

[Scubabatdan]

Ok here is a working model, I used a Radio Shack IRF510 MOSFET Transistor for testing and this design works, I connected a LED in place of the atty and the light goes on and off when the touch pads are touched.

Attached are pics and the new schematics
Dan

 

[Sir_Lawrence]

Ok here is a working model, I used a Radio Shack IRF510 MOSFET Transistor for testing and this design works, I connected a LED in place of the atty and the light goes on and off when the touch pads are touched.

Attached are pics and the new schematics
Dan

This looks great. So, you are controlling the neg connection of the battery. What if the atty's neg connection is already made? Remember, the out side of the battery connector on mine are press fit to the metal, which is the neg of the battery.

 

[Scubabatdan]

This looks great. So, you are controlling the neg connection of the battery. What if the atty's neg connection is already made? Remember, the out side of the battery connector on mine are press fit to the metal, which is the neg of the battery.

Then you would have to drill a larger hole for the atty and insert a nylon flange bushing

to secure and insolate it from the body. Then run a wire from the D post on the Mosfet to the neg on the atty. Only way I know.
Dan

 

[Sir_Lawrence]

Then you would have to drill a larger hole for the atty and insert a nylon flange bushing

to secure and insolate it from the body. Then run a wire from the D post on the Mosfet to the neg on the atty. Only way I know.
Dan

That's what I though as well. For right now, I think I'll concentrate on making the 5v versions. Now, do they sell USB cables that I can use as a 5v DC supply to the mod as well? I would like to have that options option as well...

 

[Scubabatdan]

That's what I though as well. For right now, I think I'll concentrate on making the 5v versions. Now, do they sell USB cables that I can use as a 5v DC supply to the mod as well? I would like to have that options option as well...

USB cable??? go to any flea market, or garage sale and get a USB keyboard for cheap and use the cable from it. That is what I do. Or look for cables i.e. USB printer cables in the same places.
Dan