Guide QT110 Touch-Sensitive Button Guide

Dont spose there is any chance of getting the pix in the link re-activated or re-hosted is there??
Jaz_knos

 

Hey guys.

I want to use either a QT110 or a QT113 (will test and decide later) to turn on and off all the lights in my PC. It just needs to toggle on and off 12VDC.

My friend who is pretty pro with electronics said if I use the QT110 in toggle mode, I will need a logic level mosfet. But then he got mad at me for not knowing jack sh*t about elecrtonics. Anyone wanna suggest a specific part that would work? I plan on running at most 35 LED's (2V voltage drop, 30mA forward voltage) with as many as I can in series off of a 12V line (would be 6, but I've read that I need a current limiting resistor, and with my lack of knowledge in the subject of electronics, I do not know if that is possible without dropping voltage).


Now, if anyone wants to help a fool wallbash:) get going on a slowww arse mod, I will give you a cookie.

 

Hi guys. hate to bring up old threads but i got some questions about these touch sensitive buttons. i love my touch sensitive buttons on my ps3 and want to put them in my pc when i make it and a few other things. but i need help. i dont know anything about electronics except how to solder. lol

so what id like to do is have these touch switches for:

power button
reset button
dvd drive eject button

turn case lights on and off
turn fans on and off ( would like to also have the fans hooked up to a fan controller)

also i am making a usb control panel for games and would like to have those buttons and touch sensitive also. they are just momentary ones.

i would like to have LEDs behind each spot so i can see it. ( i can mount a LED in opaque acrylic to have a little glow right? or how would i do that?

and what kind of sound thing is that shown in the first post. does it just make a "beep"? if so id like that for all buttons.

how would i wire this up or is it even possible.

the only thing i can understand of this so far is i need to make sure my electrode isnt too big. those schematics are too confusing.

i think what i'd need is a list of the parts i need and a picture showing how to wire it. i dont understand what that 'to motherboard' means or that '+5V'.

oh and is this expensive? like if it was altogether like 15-20 buttons whats the estimated price?

thank you...

 

i think i sort of understand it now after re reading this. ill wait till i get that far. i have a cousin who is i think an electrical engineer so i would suppose he could help.

 

i need a touch circuit i can use to touch and turn on. and touch again to turn the object off. Will be relay setup.

I have been reading the pdf's and see there is an infinite on setup for the 116. but will touching it again turn the circuit power off?
I'm not sure how it works exactly or how to properly wire for this?

can anyone help me or maybe draw me a quick schematic?

thanks so much

Shawn

 

i think it depends which output pin you use. one does latching switch other does momentary.

 

After finding this forum and thread from a Google search, I was pleased with how informative it was on the subject of the QT-series touch sensor ICs. I'm trying to narrow down which of the many chips Qprox makes will best fit my application.
I'm rebuilding an old style desk fan (`30s-`40s vintage) that will run a DC motor. The problem is that these old fans have chromed wire guards with spaces big enough to slide a sandwich through. I have an inquisitive 2 year old, and while she shouldn't be able to get to where this fan will be located, I'd like to add a little insurance. The plan is that the touch/proximity sensor will act as a safety; that if a finger or hand gets too close, the fan switches off (I'm contemplating also having the fan motor momentarily run in the opposite direction, to 'brake' the blade, which will likely keep spinning after the power has been shut off.) I'm thinking I need to go with a version of the QT113, for it's adjustable sensitivity, but I'm not sure which one, or if I should be looking to trigger high or low (I'm a novice hobbyist.)
Any advice you folks could offer would be greatly appreciated.

 

btt (could really use the advice)

 

no clue. im just gonna be getting the qt110's i think for my pc. i dont know what high or low means. but i would think you would want to wire it as a momentary.

you defenitely will need to adjust sensitivity as having the chrome guards as the electrode will make sensitivity huge as it will be a big electrode. maybe not. but it might sense you at a pretty good range. just get the same ones as everyone else did i would say. they arent much. only a few $'s so if it dont work get a different one.

but i'd say either qt110 or qt113

 

Yeah, as inexpensive as they are, I thought I'd get a few of each kind. I appreciate the reply, and invite anyone else with experience or insight to throw in their two cents.

 

Touch!

Got a few q-prox projects here....
PC Power switch - Power-relay switch etc...

Qprox Circuit PC Power button


Qprox Circuit latching (for power)

 

Thanks HowY. That's a helpful link.

 

One thing that you guys wanna know is that when I did this I was unsucessfull in getting this to work through some 3-4 mm acryllic. What happend was that that the voltage drop wasn't big enough to turn on the computer nor eject the dvd.

I ended up using the qt110 and an electrode on the outside instead. It's pretty neat though. One problem that I have is that I belive my psu have some glitches sometimes, suddenly it starts to eject the dvd over and over agian. I think it's cuz the output of the psu isn's stable at +5V all the time. Maybe a battery will do the thing..

It might work if you have the whole thing grounded. Eg behind the elctrode having e a big of metal connected to the ground, aswell as having the cable grounded. But still there is the problem that the voltage drop wasn't big enough.

Anyway these are just some things that you guys wanna know when doing these things. They are easy to make, especially if you just want one of em, I used three.

//Fladlish

 

hmm im using 1/8" acrylic. should that be a problem?


cant you change capacitors or somethign like that to make it sense through the thicker stuff?

 

How did you go talladega?

As far as i understand it using a smaller "Cs" capacitor will make it more sensitve but if Cs is smaller than the capacitance of the electrode it will be unstable, i think. 10-30nf seems to be reccomended.

What i would like to know is how to get it to trigger ONLY if it is double-touched, basically a double-click.
I'm guessing a touch circuit can be used to output to this double-click circuit.

I would also like to have a couple of vr's in the double-click circuit. One to adjust the required time of each touch and one touch adjust the required time between the two touches.

The idea is that only a fairly specific speed of double-touch will be accepted, and nothing else. It's to avoid accidental triggers and i like the idea of double-clicking to power the pc on or off in the same way i use my mouse to double click.

 

havent done it

not that far.

you could probly build a circuit to only output once its been 'double clicked'

i have one concern. it seems like some people are having problems with the buttons reseting or something and not working properly? am i reading this correct or do you not see this as a problem. i plan to use these for power,reset,eject,fans on/off, lights on/off and it wouldnt be too great if they mess up and start ejecting my dvd drives and turning fans and lights on or off. lol

 

The chip has different modes and if it's wired to output a pulse, which it can easily be, then the pc will turn right back on from the very next pulse output. Another possibility is the sensor electrode being too large and/or too close to devices and/or people so the circuit is unstable. And another is using too small a value of Cs relative to Cx so it's unstable. I'd say these may probably be the three most likely problems, but i haven't even built one yet.

I know the double-click circuit can be built , maybe i should have started a seperate thread asking for it, it's just i plan on using a double-click circuit with the touch sensor, which makes the touch sensor more practical i think so i posted the question here.

I bet Cinnander or Cpemma will know how to figure out what i want, maybe there are other electronics experts here i don't know about?

 

i know it can do momentary or latching which is what i'll use but i thought ive read that people have had trouble with it resetting itself if its like held down for a long time. maybe im reading too much into it and shouldnt be worried?

 

I dunno about that? The double-click circuit would remove that problem if it does exist tho!

 

How about, using a 555 timer, that on the first click of my switch starts counting and makes a single pulse after a set time. I can use vr's so i can tweak the timing of this pulse the way i want it. I then have an NAND gate, that takes in the output of the 555 circuit and the second click of my switch, so that if the double click is timed correctly, the output of the NAND will be low, otherwise the output of the NAND will still be high.

Does this sound good guys?

The one problem i have is that i want it to be open circuit, instead of being high when there is no double click. I don't wanna send 5v into the power on of the mobo, regardless if it damages the mobo or not. Should i be using something else instead of a NAND?
I think should i put a little transistor circuit that shorts the output to low only when the NAND output is low.

opinions?