anyone with knowledge of the qtouch products?

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paradoxblue

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let me state first by please do not direct me to another forum topic. as I have read all the ones I can find so far.

This is in regards to QT102 simple on/off I/C

Problem is the circuit comes default with settings for it to turn on. wait X long then turn off.
It says it's able to also touch on. stay on infinite and then simply touch off. (this is what i need)

But every time I try to draw up a diagram I come up with problems and am not sure exactly how to get it.

Could anyone help me?
heres my topic from bit-tech..
http://forums.bit-tech.net/showthread.php?t=140929
 
According to the datasheet. To override the auto off functionality you must have an external circuit that will apply a voltage pulse to reset the auto off counter. This means you will need another circuit that will pulse that line constantly to override the auto off functionality. Some type of PWM circuit.

This can be achieved by pulsing the voltage on the delay multiplier resistor Rm as shown in Figures 3.7 and 3.8.
Click to expand...

It's definitely not as simple as they make it sound in the overview of the part. Unless you are using a microcontroller, I wouldn't be able to help with the constant reset circuit.
 
Looking at the datasheet, page 8 tables 3.2 and 3.3, depending on if you want an Active High Output or Active Low Output. Pulling the Vt pin to Vss or Vdd, repectively, will give a toggle feature.

At least that is the way I understand it without something to lash up.
 
Adrenaline said:
Looking at the datasheet, page 8 tables 3.2 and 3.3, depending on if you want an Active High Output or Active Low Output. Pulling the Vt pin to Vss or Vdd, repectively, will give a toggle feature.

At least that is the way I understand it without something to lash up.
Click to expand...

Yes, I agree. The one I saw was for dynamically turning off the reset. Adrenaline is right. If the chip is in Active High mode, Vss connected to Vt will turn off the auto reset. If it's in Active Low mode, Vdd connected to Vt turns off the auto reset.
 
What are you driving with this circuit? Section 3.1.1 has the definition of active high / low. You need to decide how you want the output to behave, then wire the Vt, actually they call it TIME (Pin 6), terminal appropriately to provide the toggle feature.

If you are controlling a large load you are going to need to do something like Figure 3.4, and of course the input circuitry as described in Figure 2.1
 
i want to directly run a small led for an on/off light and then run that to a relay to control something larger.

i figured out the circuit. seems figure 2.1 was messed up labeld wrong thats hwy i didnt understand what was happening. now I just need to figure out if i want to use active hi or lo. since lo can handle 4ma and high only does max 2ma...
 
if you use one of these (in toggle mode) to drive a relay and it works, could you please post the schematic?? I'd really love to rig up a touch panel or two :)

Sadly, I'm not that great with electronics. I can build it, but I can't design anything DX
 
paradoxblue said:
i think i got it right..

http://farm3.static.flickr.com/2342/1593487264_8929c00e32.jpg?v=0
Click to expand...

Not sure what you have going on here, RL is feeding back the output to your sensor electrode?

Do you have a relay in hand or are you shopping for one? You are probably going to have to buffer the output, seeing as 2mA is not that much drive current. Is the relay controlling DC or AC current?

Arcygenical said:
What are you using for CS? A cap with around 20uf or so?
Click to expand...
The datasheet claims values from 2nF to 50nF.
 
the RL is not running to the sensor it is running to an led that will be placed behind the sensor.. Bad drawing i know.

The Cap will be probably 15nf

and as for a relay I do not have one. will need to purchase that as well.

I am currently trying to remember how transistors and such work to see if possibly using one of them to drive the circuit would work..
 
paradoxblue said:
the RL is not running to the sensor it is running to an led that will be placed behind the sensor.. Bad drawing i know.

The Cap will be probably 15nf

and as for a relay I do not have one. will need to purchase that as well.

I am currently trying to remember how transistors and such work to see if possibly using one of them to drive the circuit would work..
Click to expand...

If it works, please post back :)
 
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