All Questions
Tagged with capacitive capacitance
19 questions
3
votes
1
answer
941
views
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 ...
- 519
1
vote
1
answer
142
views
How to detect which pins on a pin display are touched using capacitive sensing
I'm working on a project to apply touch sensitivity to a modified pin display (30x30). The goal is to allow someone to interact with the display through their fingers and ideally touch.
We initially ...
- 73
1
vote
1
answer
225
views
Why are parasitic capacitances the main factor for limiting high frequency performance of active devices such as transistors? [closed]
According to the Wikipedia article, the reason for the limit of frequencies in which transistors operate is the parasitic capacitance. But I don't understand why this is so.
Wikipedia article:
...
- 141
1
vote
4
answers
478
views
Analog circuitry for measuring capacitive touch
I'm interested in adding capacitive touch input to a project I'm working on. Ideally I would like a tapered shape so that a finger can slide up as if it's a mixing desk fader or something like that.
...
- 147
0
votes
2
answers
524
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Capacitance of semi-cylindrical plates?
For a visual reference of what I mean by semi-cylindrical plates check the diagram below.
EDIT:
The above diagram is not what I intend to implement. It is just to show anyone trying to answer the ...
0
votes
2
answers
80
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How is the (dis)charging process of capacitors in series calculated?
How is the (dis)charging process of capacitors in series calculated?
I know that
$$C_{total}=\frac1{\frac{1}{C_1}+\frac{1}{C_2}+\frac{1}{C_3}+...}$$
$$Q_{total}=Q_{1}=Q_{2}=Q_{3}=...$$
$$V_{1/2/3}=\...
- 178
1
vote
1
answer
84
views
Real world objects touching reading the same capacitance?
In my project, I am developing a capacitive sensor based system which attempts to identify if two real world objects(*) get in contact with each other. I have done my homework (some) on Capacitive ...
- 123
0
votes
1
answer
54
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variation of thickness of dielectric layer for different textile-based capacitive pressure sensors
For my thesis I am working with textile-based capacitive pressure sensors and I am struggling to see how much variation in thickness of the dielectric layer you can have before you have noticeable ...
- 1
1
vote
0
answers
146
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Finding the equivelent capacitance of the circuit
Finding the equivelent capacitance of:
simulate this circuit – Schematic created using CircuitLab
I think that it should be:
$$\frac{1}{\frac{1}{C_1}+\frac{1}{C_2}}+\frac{1}{\frac{1}{C_3}+\...
- 31
0
votes
0
answers
2k
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How can I fool an auto-calibrating capacitive touch sensor?
I have a MicroBot Push - looks like this:
Below the blue ring on the top is a capacitive touch pad and a TTP223-BA6 controller. Here's what it looks like under the hood.
It's a long story, but I ...
user29392
4
votes
2
answers
2k
views
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 ...
- 153
2
votes
3
answers
509
views
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 ...
- 91
1
vote
1
answer
221
views
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 ...
- 91
3
votes
2
answers
195
views
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 ...
- 133
4
votes
2
answers
2k
views
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 ...
- 63
2
votes
1
answer
2k
views
Looking for a transparent conductive spray/paint/ink
I know there are conductive sprays available, but these are strongly coloured due to the metals inside them. I am trying to make a (dry) wooden surface capacitive, but would like to have the feel and ...
- 63
-1
votes
1
answer
504
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Grounding Plexiglass
I have a sheet of plexiglass that has metal strips (Aluminum) that will be connected through wires to an Arduino. The Arduino is grounded but the metal strips are not. The metal strips will rest on ...
- 107
3
votes
0
answers
318
views
Formulas for Integral Components
Formulas for Integral Components:
I am looking for "simple" approximative formulas for integral components. In particular for:
A grounded interdigital capacitor (i.e. above a ground plane and with ...
- 5,239
10
votes
6
answers
3k
views
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.
- 4,737