Questions tagged [capacitive]
Based on the usage of capacitors, condensators. Alternatively, utilizing the derivative of signals.
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Matrix Trackpad
I wanted to build a matrix capacitive trackpad. Ideally, its PCB would have 4 layers:
1--> The plate array
2--> The circuit that links the rows (horizontally)
3--> The circuit that links the ...
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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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How to design an accurate high tripping voltage capacitor discharge circuit
We have a system which discharges a capacitor (20 uF) charged to approx. 3kV DC using a spark gap. The principle is simple, when the voltage exceeds a certain value, it jumps the gap (around 0.6 mm) ...
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How to remotely control a TT6061A dimmer using an ESP8266 and detect its current state?
I am trying to remotely control a TT6061A (embedded inside an existing module), 3-way dimmer using an ESP8266. My goal is to set the device state to OFF, LOW, MEDIUM, or HIGH.
However, there is no ...
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I want to know if the following circuit is inductive or capacitive. What is the difference between inductive and capacitive?
I want to know if the following circuit is inductive or capacitive? What is the difference between inductive and capacitive?
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Is there a single cycle wave trigger circuit?
Is there a circuit design where if the input is high (at any length of time), the output will only be one cycle at a fix amount of time?
I'm currently working on a capacitive touch switch (I'll use ...
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Constant current AC source with a capacitive load and PID control
I have a constant-current electrical stimulator that supplies a 50 Hz square wave output. The control mechanism measures a DC current which is fed back to a PLC's PID control loop. The current ...
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Does max OP Amp Capacitive Drive Capability Matter with Active Filter?
I know that every OP Amp does have a limited capacitive load drive capability.
Even if not specified, it is always a good practice to use a series isolation resistor.
Anyway; when looking at an active ...
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How to drive 400 nF load with DAC
I need to drive a some kind of pzt transducer with a triangular 6 Vpp voltage. The transducer is modeled as a 400 nF capacitor. I want to drive it with 10 kHz 3-9 V triangular voltage however my DAC ...
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Ultra-fast load switch
I have a question that I am assuming has a very easy answer (hopefully). I am trying to turn on and off the power to a pcb really fast, on the order of 1us. My problem is that my board has some bypass ...
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Differences in capacitive loads
I'm in school and I am trying to figure out a question for homework. It reads as stated:
Version
Voltage
Clock Rate
i.
Version 1
1.75V
1.5 GHz
Version 2
1.2V
2 GHz
ii.
Version 1
1.1V
3 GHz
...
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2
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How to create a clearance area around a single PAD in Altium
I'm creating large circular pads (13.5 mm diameter) for some capacitive buttons on ALTIUM.
I want to create a circular clearance non-copper space area around each of these pads (around 1..2 mm) to ...
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What CAD software is used to design and manufacture projected capacitive touchscreens?
I am looking to learn more about how projected capacitive (PCAP) touchscreens are designed and made, specifically with laser ablation. What kind of CAD software is used to create layered drawings for ...
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Line to Line voltage in a three phase circuit with three loads
So the first load is a balanced, purely resistive one. The second one is unbalanced, and the third one is balanced. Diagram looks like this
For the first load, I'm expecting to get line to line ...
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How do I achieve well-formed pulses in a Dickson charge pump?
A picture is worth a thousand words, and I tend to make a lot of mistakes in my words, so, first picture, the circuit in question:
I know the Dickson charge pump looks a little different but it is ...
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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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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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Do projected capacitive touch panels need side clearance to ground metal?
I need to use a TFT module with an integrated capacitive touch. The TFT has it's FFC and the touch controller has its own, with power supply and an I2C interface. Quite standard, I think, since every ...
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How do self capacitance touch screens work?
I get how mutual capacitance touch screens work, by changing the dielectric around the pairs of electrode and "stealing" electric field lines. Connection to earth of the object (a finger ...
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Using capacitive touch screen without human hand
I'm trying to learn more about how to engage a capacitive touchscreen without using a human finger. Full disclaimer I'm in mechanical engineering (notoriously known to have difficulty comprehending ...
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Choosing component values for capacitive accelerometer readout-circuit
I am trying to design and simulate a capacitive accelerometer.
The idea is to model the sensor as a capacitance bridge to which an AC
signal is inserted. Each arm of the bridge acts as a voltage ...
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Inductive or capacitive load?
Here I have a series LCR circuit with resonant frequency greater than 200Hz. Is there a way to know whether this circuit is an inductive or a capacitive load?
Edit: The only additional information we ...
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Differential capacitive transducer
I would like to design a differential capacitive transducer to measure the capacitance change in an accelerometer.
I cant seem to understand, how to demodulate the signal and keep the actual DC value....
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How to know if an opamp can drive capacitive loads?
There has been a lot of questions about how to stablise opamp circuits driving capacitive loads. However, I know there are some op amps that are designed to drive capacitive loads but I am struggling ...
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Help with capacitive touch button output configuration
Can someone help me with the basic working of this capacitive touch switch? I know it isn't very complicated but I just can't get over my brain block of what actually triggers when the button is ...
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sensitivity and frequency-stability of capacitor-based oscillator circuit
I am constructing a capacitive transducer which changes capacitance as a function of changes in other physical properties. The capacitance is about 0.1~0.5 nF range, and I want to detect about 0.05% ...
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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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Bypass touch sensor IC with a button?
I want to replace a capacitive touch sensor on a circuit board (I think it’s a TTP223) with a tactile switch to overcome over/under sensitivity issues. I have wired a switch to ground and the CMOS ...
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Sensor to detect collision or intervention
I am currently working on a project (robotic arm) where I need to detect human collision with the robot. I need a sensor that should be flexible, detect human intervention in the workspace of the ...
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Pre-charge resistor and contactor power dissipation calculation
I am building my e-motorcycle. I am planning to use only one contactor instead of using three contactors. In my plan, pre-charge resistor and contactor circuit will be main contactor too. I am curious ...
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Correct design of capsense controls
I am trying to design a PCB with some capacitive controls. My first iteration did not seem to work well:
This was a 2-layer 1.6mm board with one circular control, and 5 buttons. The board is 48mm ...
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People detection in large rooms using antennas
After coming across a 2004 installation by Carsten Nicolai titled "anti" where he used a theremin as an element for presence sensing, I was wondering if this principle could be extended to ...
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Capacitive load in inverter
I'm trying to understand the effect of a capacitive load at the output of an inverter.
And how does it affect the output signal when this capacitive load is high and when it is low?
Could anybody ...
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How to detect which finger touched the mobile screen [closed]
I'm working on a project where I need to detect which finger touched the mobile screen i.e capacitive screen.
I'm not talking about double finger touch or single or drag and move etc. I'm asking which ...
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Capacitive voltage divider question
I see a few discussions on this but cannot really find the "definitive" answer.
I am building an audio amp and have two modules, one requires 18-0-18V AC and the other 12-0V AC, the 12V ...
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Bad capacitive touch screen sensitivity when running on battery, without earth
In short:
I´m working on a battery driven handheld device with capacitive-touch screen. The capacitive-touch works perfect when the PCB connected via USB, but it loses sensitivity when driven by ...
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Adjustable voltage, 1 MHz capacitive biasing
I'm a budding physicist with little electronic design experience and am interested in driving an alternating E-field of adjustable strength within capacitive loads.
Buying a several thousand dollar ...
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LED on lamp outlet flashes when switch is off - is this capacitive coupling charging the power supply? And what to do about it? [closed]
I wanted to connect an LED light chain to a lamp outlet in my house in order to turn it on and off using the wall light switch. I have dismantled the 230V to 3V power supply that was built into the ...
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Soft-start design and performant with short-circuit test
I am working on a soft-start for a capacitive load. I using module QSB40024S24 to create 24V output. At first, I allowed the output of the module to connect directly to a capacitor array (21.4mF in ...
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Calculate -3db point in low pass inverting transistor audio amplifier
What I am trying to do:
I am looking to find the \$ -3dB \$ 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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