Questions tagged [capacitive]
Based on the usage of capacitors, condensators. Alternatively, utilizing the derivative of signals.
278 questions
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Calculate -3 dB point in low pass inverting transistor audio amplifier
What I am trying to do:
I am looking to find the \$-3\ dB\$ frequency for my common emitter transistor amplifier with a capacitor in the feedback loop.
I have somewhat of an idea, but I wanted someone ...
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Capacitive load of connecting cable for a temperature sensor
An LM35 temperature sensor is 4m removed from the Arduino to connect it too. The available cable has 4 wires with a diameter of 0.6mm (0.28 mm2 area) as well as a, seemingly aluminum, shield . The ...
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Capacitive touch sensor senses every materials touch
I have a ttp223 capacitive touch sensor. It has three pins, VCC GND and I/O. I left I/O open for test purposes. I connected the VCC to 5V and GND to ground. When I touch the sensor, its led indicator ...
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Grove capacitive fingerprint sensor not working
I have just purchased one grove capacitive finger print sensor.
link.
I am using Arduino Nano and followed there tutorial but the example code isn’t working.
Blue light on sensor never turn to green ...
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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 ...
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Capacitor 250V DC
I have 0.22uF 250V DC MLCC SMD capacitor.
Can I use it for 230V AC main as capacitive power supply?
Your suggestion will be helpful for me.
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Different battery capacities in series is poor
How is the scientific (electrochemistry, physics, electrical, etc) explanation on different battery capacities in series is bad or poor and will damage them ?
user282923
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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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High-side mosfet switch placement
this is a power circuit I'm trying to complete:
the button at top turns the curcuit on, supplying VCC to mcu, and the MCU will output a high signal to a pin (marked in pink) which turns the N-MOSFET ...
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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:
...
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Finding the kVA loading after improving the power factor
This is a homework question I've been attempting. But the answer I get doesn't match with whats given and I don't understand why my method is wrong.
This is the question with answers.
Here's what I'...
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Capacitive Touch Faucet Solenoid Battery Box vs AC/DC adapter [closed]
I have a MSTJRY touch kitchen faucet purchased through Amazon. It uses a valve solenoid in line with the water supply to control the on/off of the faucet based on capacitive touch on the faucet stem. ...
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TTP223 capacitive sensor on USB switch takes two presses to work
I'm trying to solder a TTP223 capacitive touch sensor to a USB switch (specifically a "UGREEN USB 3.0 Switch, 2 In 4 Output") to rig a sort of capacitive KVM switch to a desk PC I'm building,...
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How to properly drive parallel analog switches (variable capacitive loads) with opamp(s)?
So as you can see I have 16 SPDT switches on one side of my 16 'RUT paths' and 16 SPDTs on the other side. Each SPDT(ADG1434) has two source pins (SXA and SXB) and a common drain pin (DX), 'X' ...
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Capacitive touch sense problem with battery powered laptop
I designed a PCB that includes capacitive touch. The circuit works with 5V powered from USB.
When Laptop is connected to 220V line, the PIC can sense capacitance variation.
When Laptop is not ...
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Capacitive Touch Pad Design with TTP224 ic
I am designing circular capacitive touch pads of Dia:20mm driving from TTP224 IC on my PCB. There will be 2mm glass panel above Touch pads. My PCB contains other circuits like Arduino, Antenna bands ...
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How to make sure that my compensated attenuator would work for certain pulse widths?
I have an input (one-shot) pulse that has to be attenuated by 1/2 (half). The input pulse would be of variable width in between 1us and 100ms and would have a variable amplitude: one voltage level ...
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Test device for capacitive touch screens?
Are there any (more or less) simple test devices for capacitive touch screens,
e.g. something which I can attach to a touch screen and which is able to do capacitive inputs at fixed locations (ideally,...
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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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Variac and Other dropper in line
I have a beautiful old variac, with a sliding (rotating) center contact.
I would love to use this on a nice LED string inside a glass bulb on top of the device.
But also, use the variac as the dimmer, ...
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Distribution of charges in an electrostatic study
I have a question concerning the capacitive coupling between two conductors. The capacitance C between the two is only a function of the diameter of the 2 studied conductors, the insulation thickness ...
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How to improve capactive sensor when there is a floating local ground [duplicate]
I am using a microchip MTCH101 IC as a proximity detector (based on a self-capacitance electrode) and i have some trouble in detection because of a floating local ground (i guess). The sensor is power ...
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ESP32 touch sensor outputs unstable values
I am trying to implement touch functionality of esp32 development board to toggle a led. But on uploading a simple touch detection sketch, output have spikes i.e. usually value remains near 100 but ...
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Capacitive medium range sensor with STM8
I am trying to replicate the behaviour of this library: https://playground.arduino.cc/Main/CapacitiveSensor/ with an STM8, but I am not able to do it. I want to detect the proximity of the human hand ...
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Waterproof capacitive touch-sensor issue
my goal is to develop a waterproof capacitive touch-sensor.
In many sources on the internet, it is said that a mutual-capacitance sensor can achieve this.
For example, in the TI Designs: TIDM-1021 ...
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What material can I use to block a capacitive touch from registering?
I am a self proclaimed tinkering problem solver, but this one has me absolutely stumped!
I have a capacitive touch switch panel with six touch areas that close or open a relay to supply power to ...
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How to make fast (low latency) capacitive touch buttons
I'm looking to create low latency capacitive touch buttons for a musical instrument. The response time (from physical touch to touch registered in microcontroller) needs to be around ~2ms or less.
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How is this LCD controlled?
Source: https://ozhealth.com.sg/product/genial-digital-thermometer-t15-orange/
I tore down a digital thermometer today (a Genial T15), and the interface to the LCD caught my eye: although there were ...
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Why isn't capacitive coupling considered in EMC testing?
It seems like the emissions of interest in EMC testing are radiated and conducted emissions. Is this because capacitive coupling is so weak it doesn't pose a threat to other devices?
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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 Switch To Distinguish Between Metal and Plastic
I have an application where a rotating plastic wheel has ferromagnetic inserts on the circumference of the plastic wheel (they don't stick out). Shown below in the picture is the plastic wheel (black)...
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Question Regarding Capacitive Sensor IC
I have this Capacitive Sensor IC
I am trying to understand and analyze how to use this IC.
In the datasheet, on page 13 - Function description, it is mentioned as "There are four selectable non-...
user220456
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Question about capacitive sensor designs with direct touch to copper or aluminum
I've seen some DIY capacitive touch sensor projects where the sensors themselves are strips of aluminum or copper soldered to a non-grounded wire, where the user touches these strips directly with ...
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A hole in middle of a capacitive touch screen
I'm thinking about using a capacitive touch screen (the touch layer only, no display) to detect the position of two moving parts. Each part would have its 'stylus' just above the screen to mark the ...
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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.
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Is there definitive documentation regarding the reliability of a capacitive touchscreen?
I'm working with a manufacturer who wants to use a touchscreen (like a mobile phone) to activate the machinery but is afraid the touchscreen could give a false reading.
This would be a touch-and-hold ...
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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 ...
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How to read out a capacitive sensor, (CDC, CVC, TDC)?
What are the main principles for reading out a capacitive sensor? I read a lot, but I cant figure out what re the different options.
I think that an option is to convert the capacitance into a ...
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Coax cable - capacitive load
I still have an understanding problem with impedance matched coaxial cable and its behaviour.
We do impedance matching to prevent reflections.
How does my signal source see the whole cable? At a ...
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Transfer function of a second order capacitive accelerometer
In order to find the transfer function of the accelerometer MMA7361L based on the information given in the data sheet 1 I first made a hypothesis that it a second order sensor since it has a ...
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how can I simulate the MMA7361L?
I wanted to know if there is a simulator that could include the model of the capcitive accelerometer NXP MMA7361L, and if there is a tool-box in matlab that could include it or should I find the ...
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Is there a material that I could use to generate cap touch presses? [duplicate]
I want to automate some testing that uses captouch as the interface for the human user. I would love to use an Arduino or similar's GPIO to create the equivalent press and release events from a finger....
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Bypassing Capacitive Touch Sensor on Wemo Insight
I have a WeMo Insight plug that I'd like to use to monitor the power consumption of my networking devices but unfortunately if the power goes out, the WeMo device will not come back on automatically. ...
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Where is the capacitive coupling in this adafruit soil moisture sensor?
Here is the moisture sensor:
https://learn.adafruit.com/adafruit-stemma-soil-sensor-i2c-capacitive-moisture-sensor/downloads
It has a large copper area insulated with soldermask that sticks in the ...
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Diy capacitive level measures sensor [closed]
I am trying to build an capacitive level measures sensor. I am new to this and if anyone can guide me in the right direction for a breakout card and so on.
Requires:
The size of measure level are ...
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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}=\...
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Suggestion on Power supply design
I am looking for Transformerless power supply design. I have MCU 5V. and would like to drive 12V/24V relay with single LED.
i have 4 pots 10K/200k for timing
So i prefer 230VAC to 12V/24Vdc output ...
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Predicting and Evaluating Connector Performance in a Capacitive Sensing Application
I have built a capacitance measuring system using the Texas Instruments FDC2214EVM evaluation module. The system is used to monitor the location of the user's hand in an enclosed space, where ...
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How can I override a capacitive touch on-off switch? [closed]
I bought a floor lamp for use with a mechanical timer that turns electricity on and off using a set schedule (for example, when you're away but want to convince others that you're still at home).
...
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Ground mesh under the capacitive touch pad
I am going replicate a circuit basing from adafruit AT42QT10xx, I will be using the AT42QT1010 variant.
The touch pad is the blue pad bottom layer, but there is this mesh on the top layer after i ...
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