Questions tagged [capacitive]
Based on the usage of capacitors, condensators. Alternatively, utilizing the derivative of signals.
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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 ...
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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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High pass filter is not resulting as good as the scope's AC coupling
I'm generating sine waves by using a micro-controller and DDS module. The output sine normally swings always positive between 0 to around 1V. But I want to generate a real alternating sine with ...
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How does capacitive sensing relate to the resistance of the object entering the magnetic field? [closed]
Example: Setting up a capacitive area and dropping resistors of different sizes into the field, how do they affect the field differently? Are several resistors accumulative? Would i be able to tell ...
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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 ...
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What touch circuit or sensor to use inside a concrete lamp?
Hi I was planning to build a capacitive touch circuit to control a concrete lamp.
Will the touch work through 8mm thick concrete slab. If yes please suggest best way.
Thanks in advance.
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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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Capacitive coupling: how to collect 60uA from this set-up?
I need to collect at least 60uA via capacitive coupling between a high tension Cu cable with PVC insulation and a connector that is acting as the opposite face of the capacitor (can be a copper plate ...
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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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How do I find C & L from XC and XL?
Calculating Capacitance and Inductance from Capacitive Reactance and Inductive Reactance
I'm trying to find the inductor (L) and capacitor (C) values using the inductive reactance (XL) and capacitive ...
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powersupply ac to ac
I have recently bought a dcp917S and hoped I finally found a wireless chime that I can tie into my apartment buildings bell system. Since I live for rent there I can't do any changes that are not ...
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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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Suggestions on conductive materials for textile capacitive pressure sensors
I am doing preliminary research for my thesis. The thesis involves textile capacitive pressure sensors. I am trying to find out more about how the type of conductive material used affects the ...
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AT42QT2160 capacitive touch controller inverted Cs voltage - no touch detected
I'm trying to make my own development board for the AT42QT2160 Touch controller, since the original one was discontinued. I've designed the PCB with 8 buttons and a slider consisting of 8 sections. It'...
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Shock from Capacitive Coupling
In an AC supply which is not earth grounded, I see a small amount of current flowing to ground from both wires of the supply (live wire has higher) even though the circuit is incomplete.
It is due ...
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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}+\...
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Using a straw filled with electrolyte as stylus?
Now what I understand is our human body or a stylus disturbs the electrostatic field of a capacitive screen and thus the mobile calculates the disturbance and does some math and registers a touch.
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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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capacitive touch buttons through VERY thick glass or macrolon? [closed]
for a science-project I need to create 4-5 capacitive touch buttons through thick glass or macrolon. I think we talk about 15cm atleast, if not 20. I wonder if a big coil or big sheet of tinfoil would ...
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2D DIY capacitive panel
I'm planning on replacing lights with smart bulbs (e.g. Yeelight RGBW) and replacing light switches with capacitive panels connected to Arduinos which will send data to RPi, which will then control ...
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HF signal in a null experiment. What is the exact mechanism?
Since I've tried to experiment with electronics, I am faced with the problem of HF noise and signals bypassing almost anything I try to stop them. This begun with my attempts to filter the noise of a ...
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Marvell PHY to KS8999 PHY connection
I'm trying to design a custom board with Marvell 88E1111 PHY and I want to connect this board to another board with KS8999 PHY on it. I want to connect two phy sides with capacitive coupling.
The ...
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capacitive sensing PCB overlay
reading some of the capacitive sensing IC datasheets around, they always recommend an isolation overlay over the sensor pad.
Like this:
I'm wondering, why not use the actual PCB as overlay?
like ...
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Wiring RGB Vandal Switch as PC Power Button
I'm trying to wire up a Schurter CPS16 capacitive, multicolour (RGB), anti-vandal switch to my PC for use as a power button.
The switch function is momentary and normally-open.
Tech Sheet
I'm just ...
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Reliable way of measuring mains voltage by capacitive coupling with oscilloscope
The question is not about any precise measurements, just for the lack of a better title.
Trying to model what one of those non-contact voltage detectors would see when brought closer to a live wire.
...
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AC mains wire finder + live wire equivalent circuit [duplicate]
I'm talking about devices for tracing hidden AC mains wires in walls like this one: https://www.ebay.com/itm/3-in-1-LCD-Wall-Detector-Stud-Center-Finder-AC-Live-Wire-Metal-Detector-Scanner-/...
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What is the chip used in CJMCU 0401 Capacitive Touch sensor?
I'm trying to make my own PCB with touch keys. I've used the CJMCU 0401 capacitive touch sensor module and now I want to use it in my project. On the chip that is used in this module, there is only a ...
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capacitive reactance in a stranded wire
Can a stranded wire exhibit a capacitive reactance?
I measured the real and imaginary part of a piece stranded wire using an old LRC meter( HP 4284a).
Applied an open loop and a closed loop ...
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capacitive switch behind a mirror (silver backing)
I am new to this field, and I would like to DIY a mirror with a hidden capacitive \inductive touch sensor behind it, once touched it will turn on a 12V LED light.
I have bought a capacitive switch ...
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Capacitive sensor as drop-in replacement for mechanical button
I have a device X (talking toy), which has a jack of two wires for an external button. That is, I can short the two wires and device X accepts it as a press of a button.
Now, I want to use device X ...
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ATtiny13a capacitive power supply
I would like to power my Attiny13a MCU with a transformerless capacitive power supply. The MCU itself needs only a few milli amps and it will drive 2 LEDs at 15mA each through it's digital pins. So I ...
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Figuring out the protocol of an SPI device without a datasheet
I am pondering about interfacing with the iPad Mini 2 touch panel. It seems that no one has successfully done this and/or published anything about it, so I want to take a stab at it.
As far as I ...
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Modelling a "scope probes' acting as an antenna" phenomenon in a circuit
Here below I draw a simplistic model for stray capacitance issue in SMPSs:
Basically pF level Y capacitor across the AC line forms an RC voltage divider when measured by a voltmeter with respect to ...
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Transistor selection for 5V LED circuit
I'm having a trouble selecting the proper transistor to switch this LED circuit
simulate this circuit – Schematic created using CircuitLab
The LEDs are 3.6v at 20 mA.
I tried figuring the ...
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PCB stackup for capacitive buttons, LEDs and other components
The design I am working on has about 30 capacitive buttons, LEDs for back-lighting, about 8-10 ICs (capsense controllers, LED drivers, MCU, etc), many passive components and coin cell batteries.
I am ...
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Design of capacitive proximity sensor
I am currently designing a microgripper for which I need a proximity/distance sensor.
Please refer to the image below for design requirements.
Due to the force application (as shown in the image), ...
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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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Is it a disadvantage for a generator to supply both resistive and reactive current to its load?
Suppose
The power network 1 has a resistive load and therefore the current supplied by the generator 1 to the load is purely resistive.
The power network 2 has a resistive + inductive load and ...
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Rugged Capacitive Single Touch Screen
I am looking to make a capacitive single touch screen into a small table. Which I can use to put coffee cup etc on. It does not have to be waterproof but rugged enough to not scratch over time easily ...
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Peak value of sine wave for capacitively coupled inverting amplifier
I was working on question 2.23(a) and there is asked what input voltage is needed in order to ensure that the output does not clip. The clipping limits are +10 to -10 V.
I solved that, and, ...
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Digital control over capacitive touch
I would like to generate computer controlled touches on a capacitive touch screen (e.g. iphone) using the following setup: I have a conductive patch (size of finger) that I place on the touchscreen ...
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Capacitive proximity sensor size?
I want to design a capacitive proximity sensor to detect human presence at a distance of 10-15 cm.
Now I made my research on this type of sensor but everything that i found doesn't tell me about the ...
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Eliminating ghost voltage and breaking ground loops in a system
The above illustration is a setup I use where amplifier outputs go to a data acquisition system through BNC cables. The data acquisition system is earth-grounded. Mains system voltage Line to Neutral ...
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Capacitive sensor - How to activate with a portable device
I'd like to activate a capacitive sensor - a smartphone touch screen for instance - with an electronic device - say an Arduino board. Basically I'd like to reproduce this instructable, but with one ...
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Capacitive sensing with large distance
I am curious on how capacitive sensing work. How does it sense hand gesture, or measure water level when the distance between the capacitance plates are large (5-10cm)?
I thought that capacitance ...
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Wall touch switch design
How can I make a capacitive wall touch switch? remembering that the wall standard light switch has just two wires for close the circuit. How can I supply my circuit when the light is on in order to ...
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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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How does the glass screen of smart phones not block the discharge of capacitors in capacitive touch screens?
Glass is one of the best insulators when designing high voltage electronics, and correct me if I'm wrong, but capacitive touch screens work by measuring the charge of capacitors in a grid on the ...
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Is electric field of capacitive sensing circuit harmful and is it radiation?
I have constructed a circuit for capacitive sensing. The code charges and discharges a conductive plate. This uses an Arduino which is connected to a computer via USB.
I have decided to measure the ...
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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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