Questions tagged [capacitive]
Based on the usage of capacitors, condensators. Alternatively, utilizing the derivative of signals.
278 questions
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How can human finger pressure be measured?
I am dealing with a situation where a patient can only very lightly press his fingers / hand to signal what he / she wants. Speaking or eye tracking is not possible.
The person is also not able to ...
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How to use a capacitive touch screen without a human hand
I'm a programmer, and I usually hang out over on stack overflow, but I have a electricity question.
I'm trying to interact with an APP on my phone by indirectly touching the the screen. Modern ...
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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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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 is capacitive loading? (Intuitive understanding)
I have read about capacitive loading, but what does it actually mean intuitively?
I just asked this question so as to get an intuitive answer and also know what should I understand when one says that ...
user220456
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Capacitive Sensing
Is there a way that I can make an Arduino or other Micro-controller detect a change in capacitance?
I'm thinking of having a screen on my door that only turns on when you touch the metal door handle.
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Triggering a capacitive sensor electronically?
I'm working on a little project I call my "Green Box". Basically, I'm trying to drop my electric usage as low as possible, without losing the convenience of my gadgetry.
So far, I'm incorporating a ...
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Driving LM3886 at 100 KHZ in Bridge Tied Load (BTL) configuration?
Would someone have experience with driving a pair of LM3886 Overture Power Amplifiers in BTL with up to 100 KHz sine wave?
My parameters:
Frequency band of interest: 20KHz to 100 KHz, sine wave
...
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Conducting plastic for capacitive touchscreens
As I am disabled I have to use a headstick (see picture below) to do stuff on the computer. I also have a phone with a resistive touchscreen, which works well with my headstick.
But here is the ...
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Help understanding/selecting SMPS to drive capacitive load
I recently bought several SMPS buck converter supplies for a project. They all had about the same specs, typically 90-270VAC input, 12VDC output. Having an expected worst case continuous load of about ...
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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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Capacitive AC voltage detection
As I understand it, a non-contact voltage tester works by creating a capacitive connection from a power line to ground, via the detection circuit and the operator's hand/body. This connection passes a ...
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Capacitive touchscreen [duplicate]
I am doing project in which I want to perform read and write operation by using a capacitive touchscreen. What I know is I can trigger capacitive touch screen by:
By using electromagnet as I heard ...
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Headphone Noise from Laptop SMPS
I have been facing an issue that has been a mystery to me for quite some time, and I wanted to see if someone here can potentially give me more insights on this so I can understand why it is happening....
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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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Can a water drop do a "fake" touch on a capacitive touchscreen?
If a capacitive touchscreen is hit by water drops, like rain, will it report a touch?
I'm trying to evaluate what is the most appropriate touchscreen solution to use in an outdoor kiosk.
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Simplest touch sensor for a copper surface
I'm looking for the simplest way to implement a binary on|off touch switch using a single pole. The touch surface is copper. The position or pressure of the touch is not needed, just simply:
On = ...
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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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How do I trigger capacitive touch screen electronically (without hands)? [duplicate]
I would like to trigger a "touch" or "touches" to a smartphone screen electronically without actually touching the screen with my finger using a remote control somehow.
The idea would be that every ...
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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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Does this circuit, used to subtract capacitive response, have a specific name (picture in body)?
What I'm doing:
I'm applying voltage pulses to thin films and measuring the resulting current transient, then using these transients to extract the hole mobility.
The problem:
When the films are ...
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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 load of PSU
I see many power supplies have a parameter called max capacitive load. In this case for the below PSU, it is 2200uF.
What does this mean exactly?
I cannot measure the capacitance of the load easily so ...
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Why is this camping light deadly?
I am learning, so go easy on me, if you can.
In a video with BigClive, he takes apart a camping light and says it's deadly when you have mains plugged in and usb plugged in at the same time. In that ...
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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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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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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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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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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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How can I build a touchpad/trackpad? [closed]
Every laptop has one - a touchpad/trackpad - for controlling the mouse.
I'd like to build my own, external one. I've looked around and I cannot find a tutorial. I have come across 1 example where a ...
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Using a TPP223 capacitive board instead of a mechanical button
I have this CSR8645 bluetooth module and I wanted to use TPP223 capacitive buttons for its inputs - vol+, vol-, next, prev, etc., but I am wondering if it will work at all.
The CSR8645 is originally ...
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Capacitive touch screen sensitivity question
I have a question about capacitive touch sensing. I have read a few related questions already (here, here and here) and I think I understand the basics.
From my understanding, when a human uses a ...
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Capacitive touch sensor design
I made a PCB with several capacitive pads to be read by IQS127.
They work, but any material I put close to the PCB surface will trigger the output, even the 8 mm glass I'm going to use.
The pads ...
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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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Is there a 10X probe compensator BNC, but with out the probe?
Is there such thing as a compensation BNC like the ones found on 10X probes? I'm basically taking about a BNC coupler with a resistor and a adjustable cap in it. I guess it would be like a standard ...
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Capacitive dropper failure
I have some fridge led light based on basic capacitive dropper. If I connect circuit to AC mains nothing happens. At first I checked all components for mechanical damage and than measured them out of ...
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How to drive and control capacitive load?
There is electrochromic film (which is some kind of capacitive load) that need to be driven with 50Hz alternating current, load voltage should be controlled in range 0-100V (with 8 or more fixed ...
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What are those black things on the board?
I'm a beginner in electronics, and I'm ignorant of many basic things.
Check out these black things on the board:
These are from a keyboard.
I'm disassembling it and I want to connect my own ...
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Is FR4 waterproof? What about soldermask?
I'm investigating ways of making a capacitive sensor that will operate in very moist environments, potentially even submerged. What I need is a way to make some conductive plates in a specific ...
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What is the maximum reasonable cable length for a humidity sensor?
I have an ESP32, and use capacitive soil humidity sensors to check the humidity of my plants. They get shipped with about 15 cm of cable attached.
What is a reasonable/safe cable length I can use ...
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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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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 ...
user59094
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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 can I use a microcontroller to trigger an existing capacitive-touch pad?
(Note: I have found several other questions on a similar topic, but none of them address my specific issue.)
I have a lamp that is controlled by non-contact touch buttons. The user-facing surface is ...
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How do capacitive touchscreens really work?
I have a bit of trouble understanding the electrical laws which apply when I touch a capacitive touchscreen with my finger.
Apparently, there is an electric current running through electrodes below ...
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Reverse-engineer pinout of capacitive touchscreen
I'm interested in reusing the capacitive touchscreen of my old iPad. (As a learning experience -- I'm aware that this project will cost me more than just buying a new capacitive touchscreen would.)
...
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Can transformerless power supplies be UL/CSA certified and is there any specific standard they must meet?
I am trying to bias a linear optocoupler on the AC mains side of a circuit, in order to transfer analog information to the secondary side of the circuit. I have designed the following capacitive power ...
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How do capacitive screens work with rubber head stylus?
Now I kind off know that Capacitive Screens have like capacitors built into them that create an electrostatic field. Now whenever a thing that can carry charge or a conductor touches it distorts the ...
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Capacitance on the output of an op amp
I have read a lot about capacitive loads on the output of an op-amp and the possibility of unwanted oscillations and instability. my knowledge on phase margin and frequency domain analysis is a little ...
