touch activated button

[alexRO]

hi my name is Alexandru, i am from Romania, i don't know if i've posted where it should be but here it goes.( please to admins to move the post if i didn't posted right)

I want to build a touch sensitive button (like the LG chocolate has them), this buton will be used in a computer case mod.
It will have the function to turn the pc ON and OFF , and if it works well i will later implement it to open the DVD case and restarting the pc.
The trouble is that i can't find schematics for this button so i came and ask some help from you guys, if someone tried something like this, or if someone has the schematic for a touch sensitive button please answer this post, thanks in advance

Looking forward, to talk
Yours Alexandru

 

[ericgibbs]

hi my name is Alexandru, i am from Romania, i don't know if i've posted where it should be but here it goes.( please to admins to move the post if i didn't posted right)

I want to build a touch sensitive button (like the LG chocolate has them), this buton will be used in a computer case mod.
It will have the function to turn the pc ON and OFF , and if it works well i will later implement it to open the DVD case and restarting the pc.
The trouble is that i can't find schematics for this button so i came and ask some help from you guys, if someone tried something like this, or if someone has the schematic for a touch sensitive button please answer this post, thanks in advance

Looking forward, to talk
Yours Alexandru

hi,

There are links here:
https://uk.search.yahoo.com/search?fr=ytff-yff3&p=touch sensitive button

This one:
**broken link removed**

 

[alexRO]

hi again, thanks ericgibbs for answering to my post, the project in the second link is a very good one but in my case not, beacouse i cannot find the IC QT110 in any shop from my home town and i don.t know if i could replace it with something else and still work, please if you have something else or an ideea on what i could use instead of the QT110 please answer to me.
Thanks in advance and for the time u spend to help me

 

[ericgibbs]

hi again, thanks ericgibbs for answering to my post, the project in the second link is a very good one but in my case not, beacouse i cannot find the IC QT110 in any shop from my home town and i don.t know if i could replace it with something else and still work, please if you have something else or an ideea on what i could use instead of the QT110 please answer to me.
Thanks in advance and for the time u spend to help me

hi,
Can you buy in your shops say, CMOS, 4049 or 4050 ic's.???

Where are your shops.???

 

[alexRO]

i guess i can buy them why do u have a schematic wich use the components u mentioned, if yes i will try to go shopping for CMOS tomorow morning.
Well the shops........i live in Romania in the city of Bacau so the shops are in Bacau

 

[ericgibbs]

i guess i can buy them why do u have a schematic wich use the components u mentioned, if yes i will try to go shopping for CMOS tomorow morning.
Well the shops........i live in Romania in the city of Bacau so the shops are in Bacau

hi,
Now that I know that you can get CMOS, I'll draw a circuit, post it tomorrow.
So dont go shopping until I post the circuit.

 

[alexRO]

Many thanks for the help, it is quite strange that in all the romanian forums about electronics they didn't helped me and someone from other country very far from me offered to help me.............
Many thanks again ericgibbs

 

[ericgibbs]

Many thanks for the help, it is quite strange that in all the romanian forums about electronics they didn't helped me and someone from other country very far from me offered to help me.............
Many thanks again ericgibbs

hi,
These are the types of DIY touch switches I was going to suggest.
Which type would be best for you application.?
Let me know and if possible I'll build and check it out before you spend money.

http://www.discovercircuits.com/C/capacitance-sw.htm

 

[alexRO]

hi, i think this should work for me
http://www.discovercircuits.com/DJ-Circuits/fingersw.htm
as well as this
http://www.discovercircuits.com/DJ-Circuits/5vmom1.htm

thanks for the help i appreciate this

 

[ericgibbs]

hi, i think this should work for me
http://www.discovercircuits.com/DJ-Circuits/fingersw.htm
as well as this
http://www.discovercircuits.com/DJ-Circuits/5vmom1.htm

thanks for the help i appreciate this

hi,
The first circuit looks nice and simple.
I'll give them a try, using equivalent parts.

 

[ericgibbs]

hi,
I have tried those circuits.

Looking at your application for powering up the PC, I would suggest they are not reliable enough.
They tend to pick up noise and they could switch the PC On/Off when its not required to do so.

Also this type of touch switch requires additional electronics and mains power isolation if you plan to switch mains power.

There are available low profile tactile switches which would simplify the design and could drive a opto isolated triac circuit,

 

[alexRO]

hi,
thank you for testing them for me, i think i ll change my mind and use instead of the touch sensitive, a little tactile button, i wonder if i need a circuit for the button or just wire up the button and connect it to the motherboard.........

Alex.

 

[ericgibbs]

hi,
thank you for testing them for me, i think i ll change my mind and use instead of the touch sensitive, a little tactile button, i wonder if i need a circuit for the button or just wire up the button and connect it to the motherboard.........

Alex.

hi,
The PC should already a On/Off push button.?

 

[alexRO]

the case that i am modding has already the ON/OFF push button but is big old and noisy, the initial idea was that the front panel of the pc would be covered with a 3mm plexy sheet and the touch sensitive button behind it.
now i changed the design and i ll use little tactile buttons instead of the touch sensing.
how can i post a picture of the case??

 

[ericgibbs]

the case that i am modding has already the ON/OFF push button but is big old and noisy, the initial idea was that the front panel of the pc would be covered with a 3mm plexy sheet and the touch sensitive button behind it.
now i changed the design and i ll use little tactile buttons instead of the touch sensing.
how can i post a picture of the case??

hi alex,
So you are a 'modder', that explains a little better what you are doing.

to post a picture:
Click the REPLY button.
Scroll down and you will see a 'MANAGE ATTACHMENTS' button
Left click the button and a upload window will open.
Use the BROWSE button to locate the picture on your PC.
Click the UPLOAD button, wait until done and close the upload window.
When you have completed the post click the Submit button, as normal.

You will need to type in some text in the reply window, as normal

BTW you can attachment more than one picture IIRC it can be 3 files.

 

[alexRO]

**broken link removed**

this is the design of the case

 

[alexRO]

this is it

 

[ericgibbs]

this is it

hi,
Whats the processor.?

A finger print recognition pad for ON/OFF would be 'cool'.

 

[alexRO]

that would be way too cool, my current procesor is AMD 3200+ 2.01Ghz but i am thinking of getting a bigger one i don't know yet

 

[killivolt]

Finger Print Recognization.

hi,
Whats the processor.?

A finger print recognition pad for ON/OFF would be 'cool'.

I keep getting people wanting me to buy one of those. I want one for my house can we program it to recognize multiple prints. My kids always loose the key's costing me a fortune.

kv