Questions tagged [capacitive]
Based on the usage of capacitors, condensators. Alternatively, utilizing the derivative of signals.
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capacitive touch film or integerated capacitive touch panel display? using under glass [closed]
We need to put display under 2mm glass. Our device must have capacitive touch input.
which method should we use? Capacitive Touch Films (place it under glass) or LCDs with integrated capacitive touch (...
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PCB trace capacitance
I am designing a capacitive touch keypad using cypress MBR series. The design guide has an excel spreadsheet to help with max trace length and button dia requirements. The idea is to keep the button + ...
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Sensing the capacitance value of a material - for an ID system
This is a follow up question to 'How does a Capacitive ID / Signatures / Sensing system work? e.g. Google Bloks'
In the 'Google Bloks' project. A tangible programming experience is created by ...
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How does a Capacitive ID / Signatures / Sensing system work? e.g. Google Bloks
In the 'Google Bloks' project. A tangible programming experience is created by allowing children to place physical instruction blocks next to each other.
The computer is able to read the sequence ...
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Homemade shielding of a wire to a capacitive sensor
I'm using a capacitive sensor CAP1188 with Arduino, connecting 8 of its touch sensor inputs to 8 copper boards that I want to be the actual touch surfaces.
The wires to the sensor are quite long (100 ...
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Water level capacitive probe topology
I'm building a small capacitive water level sensor for a reservoir (16cm tall x 10cm x 7cm).
This prototype gives me 10pF on free air and 20~30pF on medium water levels, so its definetively doable (...
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Elegant non-mechanical way to switch on battery-powered device the first time
For a primary-battery powered device, that will be stored for a period of time before first use, what is the most elegant non-mechanical* way to switch it on for the first time, after which it will ...
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Making conductive traces for capacitive touchscreens
This is a follow-up to this question I asked years ago.
A short summary:
I'm using a head pointer (see my linked question for a photo) with a tip made of plastic, thus non-conductive. The shaft is ...
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Designing a Transformerless power supply
I am working on a transformerless PSU for maiking a 3nos.x3 watt led, each having forward voltage around 3.6v and current around 650-700ma.
I have worked on this kind of circuit:
I guess a 1uf ...
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How do you measure soil moisture using a capacitive sensor?
There are a number of capacitive moisture sensor designs on the internet, which use the insulated copper pads on a PCB.For example:
http://zerocharactersleft.blogspot.in/2011/11/pcb-as-capacitive-...
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Capacitive Coupling Between Adjacent Conductors
I have been unable to find a definitive answer to my questions after some extensive browsing online.
My question involves the coupling between two adjacent conductors (wires, PCB traces, etc) due to ...
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Heartrate measuring using capacitive touch sensor
I am new here, and I hope someone could help me.
So I've read in the datasheet of the capacitive touch sensor ATMEL42QT1011
that we could use it as a heart rate sensor.But what I don't understand is ...
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Simple short range object proximity identification using capacitive sensing
I'm designign a device capable to sense proximity with other identintical devices and communicate that to a central node via bluetooth. The problem I'm trying to solve is showed in figure.
So far I ...
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Insufficient ground supply on my circuit? Ground capacitive foil
I'm playing with a wireless sensor device (with atmega, xbee, and Capacitive sensor (simple foil)) that works fine with the lab power supply but as soon as I try it with AA batteries stops working. ...
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Capacitive touch switches drop voltage and limits current
Bought two different touch switches/devices to toggle outputs to other devices. I use this on USB power so input is 5V. With use of a powerpack it can handle 2A max.
NOTICE: Ask my question here ...
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How to do capacitance measurement with high frequency oscillator
There are many types of capacitance sensors. I recently come across moisture sensors which measure the dielectric constants of the materials and correlate them to the water content level. It turns out ...
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How to obtain the transfer function of the capacitive sensor?
I want to obtain the transfer function of this capacitive sensor which in the circuit, C is the variable capacitor that transforms displacement to electrical signal and E is the dc voltage source ...
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How does capacitive EEG electrodes measures EEG signals
I have read the following sentences from an article:
The effect that there are also charge displacements on the body
surface due to brain activity is used for the capacitive measurement
of the ...
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Which MCU (Atmel) I can use with QTouch library?
Some MCU have QTouch support - # touch channels implemented as a hardware. Is it true that QTouch library was designed only to work with such MCUs? Can I use it with, for example, 'old' ATmega48? Is ...
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Capacitive Moisture Sensor - Is AC or DC better/more accurate?
I am looking into making a capacitive moisture sensor. This has been discussed many times already, but I am not sure what is the better option, AC or DC.
I want to run this off of a battery, so DC ...
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Is there any material that obstructs or resists capacitive sensing?
For example, is there any material I can place over a capacitive sensor, or the finger or conductor approaching it, so that the sensor will no longer activate?
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Excessive temperature on cheap soldering iron - will series capacitor fix it?
Soldering iron came in a $14 USD kit off eBay. Lots of neat stuff, but the iron became so hot as to badly damage a DIY Kit. After a 2nd chance w/ the same results, it was hacked, Heating element of ...
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Trigger capacative button
My washing machine is equipped with a capacitive start button. A "button" is marked with paint on the plastic front and on the backside of the panel there is a spring extruding from the control PCB, ...
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What material can I lay over a capacitive touch screen that will still make it work?
So I am trying to build a capacitive touch screen in a table, but since the table is much larger then the touchscreen. I like to put something on top that not only make it easier to clean, but also ...
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Touchscreen Sniper [closed]
I was reading today about how capacitive touch works. This article on the Arduino site mentions that with a 40 Megaohm resistor you could detect an untouched "touch" from possibly 24 inches away.
My ...
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Capacitive ECG electrodes and capacitor discharge
I am trying to make ecg electrodes with capacitive coupling. Since my capacitor is only about 10 pF at max and I have to have as low cut-off frequncy as possible, I came up with a circuit like this. ...
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How to calculate inductive and capacitive reactance?
I am studying a project that calculate reactance power. I can measure apparent power, real power and power factor. Therefore I can calculate total reactance power. But I don't know whether it is ...
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What are possible reasons for this not to work
I connected a 5V relay to an Arduino. It then opened and closed the relay, which had on a terminal (doesn't matter which one?) a wire that went to an iPhone' screen (with tin foil at the tip). On the ...
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Capacitive Sensing and Dielectric Coupling
I have a design that uses the MPR121 capacitive sensor. It's a very simple board with 10 "slider electrodes". Standard 2 layer construction with FR4 .063" thick.
The board interfaces with a ...
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QTouch Matrix ATmega8 issues
After trying a lot on QTouch Matrix for ATmega8,It didn't work for me. So sharing the trouble here.
I have taken reference from this beautiful article. Here he had provided a schematic and PCB ...
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How can I interface to a capacitive sensor and measure its value with my Netduino?
I've just bought a rain detector, not realizing it is a capacitive sensor (I had assumed it was going to be resistive, as most are). However, being capacitive means it can be sealed so no electrodes ...
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Need help for calculation of this capacitive power supply
Look at this circuit. It's an almost complete capacitive power supply with necessary part.
simulate this circuit – Schematic created using CircuitLab
I have trouble calculating:
the input ...
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capacitive power suplply
i have following doubts about capacitive power supply or transformerless power supply...
what will be real power drawn, will it be 230 x (current flowing through C1) or 6 x (current flowing through ...
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Feasibility- Flex Capacitive Touchpad
I'm a student(don't know much on Eagle) working on a project where I need a way of multi-touch finger tracking on flexible material. Will flex pcbs work?
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What sensors can accurately detect size of content in a closed container such as number of pills in a pill box?
I am a DIY enthusiast playing with different sensors and electronics.
Recently I've been trying to make a pill box for my grandparents to track their medicine intake. However, I cannot determine ...
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What is the minimal capacitor (capitor type/size/capacity) needed to fool a capacitive touch screen? [duplicate]
Say I want to provide a device (completely batteryless of course, and detached from any human touch) the capability to immitate a touch on a capacitive screen (Galaxy S6 here). I know I just need some ...
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What material can I lay over a capacitive touch screen to block its operation, while still allowing me to see it? [closed]
I own a Kindle Voyage and would like to be able to hold it anywhere, not just along the edges, while reading. So I'm looking for a material that's clear to read through, relatively lightweight, and ...
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capacitive sensor and wire length
I'm a newbie and I've been playing with the awesome Adafruit CAP1188 capacitive touch gizmo.
As long as I keep the length of the wires from the CAP1188 to my copper sticky pads to a couple of feet, ...
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Capacitive sensing between two copper plates
Is it possible to detect touch event and its position coordinates between two copper plates spaced apart by approximately 6-7 centimeters? The space between plates have to be transparent.
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Finding the touching angle on a touch-screen?
I am wondering if it is possible to detect from which direction (or at which angle) a human touches a touchscreen.
Imagine something like this:
Is there any technology out there (e.g. special ...
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Given the dynamic and static power consumption how does one determine the total power for the capacitive load?
I get that the capacitive load is determined which is also indicated by this question:
$$\frac{Power}{Voltage^2 \times frequency} = Capacitive Load$$
However, I am not sure how power (which is ...
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capacitive touch screen
I am currently trying to build a capacitive touch screen. My end goal is to create a giant track pad/keyboard for my computer. Since abnormally large touch screens are quite pricy I have set out to ...
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Are capacitive display(s) capable of measuring what fraction of a finger is touched?
I'm really curious to get an answer for this question. Since I don't know the functioning of a capacitive display and Google didn't help me on this issue, I landed here. :)
Are capacitive displays ...
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Inrush current limiter - design questions/review
I am considering to use the inrush current limiting circuit that was suggested in this answer.
I have a pretty big capacitive load of about 40000uF to charge. Its a buffer for a GSM modem that needs ...
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Capacitor Touch switch with QTouch
I have been working on QTouch Implementation for ATmega32 Micro controller.
I have taken reference from here. I'm facing issue with grounding Problem.
For debugging process I am displaying the result ...
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Causes of ringing in a PCB
Im trying to understand the source of ringing at the termination point of a PCB traces before i delve into actually designing a PCB. For example, by 'termination point', I mean a clock signal ...
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Capacitive touch directly above LEDs
I'm trying to make a design where the user can run his/her finger directly over a series of 10 LEDs (covered with 1 mm glass), and the LEDs should glow on/off based on the finger's position.
I wish ...
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Capacitive touch on off power switch
Is is possible to use capacitive touch as a power switch for an embedded project?
Can a microcontroller turn itself off and somehow still monitor an input pin? Or is there a dedicated IC that can ...
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Calculating the voltage out of this particular cap coupled circuit
Before I get to my question, I'll just go over the input and output of the circuit from what I "know". The base of the BJT gets a 20 microsecond pulse that puts the bjt well into saturation and "VOUT" ...
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Capacitive Touchscreen for DIY usage?
Anyone know of a good source for capacitive touchscreens in low quantity at a reasonable price? Just something to play around with in projects, I'm interested in either small (eg for portable ...
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