Questions tagged [capacitive]
Based on the usage of capacitors, condensators. Alternatively, utilizing the derivative of signals.
278 questions
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Convert capacitive touch sensing back to mechanical switches?
Capacitive sensing seems to replace often mechanical switches. Is there a way to convert them back to mechanical switches?
Problem at hand is a cooking device with interfaces with the user via the ...
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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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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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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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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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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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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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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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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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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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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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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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How to make 1 bit permanent memory circuit?
I would like to make a simple circuit to store or save 1 bit of data. The circuit should be able to remember the state of an LED ( on or off ) even if the supply is disconnected from the circuit. I ...
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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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Simple capacitive proximity/touch sensor problem
I've found one simple schematics for capacitive sensor on electronics-project-design.com, and implemented it as follows:
The B? is 9v battery. Sorry for the odd-looking schematics: gschem usability ...
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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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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 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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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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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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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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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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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 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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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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Electric shock from laptop due to capacitive coupling?
If a person touches an exposed wire (the wire has a ground-prong) on the 20V side of a power cable while barefoot, I heard that it is possible to receive a shock of higher than 20V due to capacitive ...
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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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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 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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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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Is a capacitive touch screen safe to use?
I was reading about capacitive touch screens. I understood that your hand picks some current flowing on screen. That sounds alarming.
Is it safe to use a capacitive touch screen, since it picks small ...
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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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Given a load, how do you calculate whether it is capacitive or inductive?
If the impedance at the load has the form of \$Z = R + jX\$, where \$R\$ and \$X\$ are positive real numbers, then then network is called inductive. If \$Z = R - jX\$, then the network is called ...
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Capacitive where is the touch?
I am a newbie in the world of circuits and electronics. But we all started somewhere.
I have this idea about a street sign that should be used as an instrument. All most like a Theremin. Touching it ...
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How can I make a POWER-LED Lamp?
What is the best way to light 10 POWER-LEDs with AC mains (220V)?
(I want to make an LED lamp.)
Here is more info:
I have 10 of these POWER-LEDs:
Product Chip: 40x40 mil
Chip Brand: EVERLIGHT-...
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Choice of sensor for detecting touch (on/off)
I would like to detect a user's touch on a shop window (at a specific area, there would be a 'call to action' marking on the window, i.e. 'touch here')
Any sensor to detect this must be contained ...
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Can I use a capacitive sensor to detect a person proximity without touch?
I only see uses of capacitive sensor to detect touch. But I wonder if I can calibrate a capacitive sensor to detect if a person is close enough, even if the person is not touching it.
I intend to use ...
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Capacitive load at the output for analysis of CMOS cells
This question is very rudimentary one. Please point me to the link if this question has been already asked.
In general, when working with simulations and and analyzing the standard cells designed ...
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How can I make a fine tipped object emit an electric field similar to that of a human finger?
I've asked this before, but knew less about the tech and didn't word the question properly. I know other people have asked similar questions and knew little, so let me be as specific as possible here:
...
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What exactly does a capacitive touch screen need to register input, and how can that signal be produced?
There are active styli out there, and they take 3A or 4A batteries and don't require any wireless connection. How do those emulate human touch?
EDIT: I am specifically interested in iPad touch ...
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Making a grounded object capacitive
I am trying to make a copper pipe which is placed in a natural park capacitive. It is placed in the soil meaning that it is already grounded. I am using a basic arduino and their capacitive sensing ...
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