Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [capacitive]

The tag has no usage guidance.

0
votes
0answers
31 views

How to safely switch a big inductive load with a Triac using a capacitor snubber?

I am building a Spot Welder with a big powerful transformer. I have to switch a big inductive load of 70mH (input of a transformer) The switching will be done with an SSR (Opto Triac Zero crossing SSR-...
1
vote
1answer
31 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 ...
0
votes
2answers
75 views

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 ...
0
votes
1answer
57 views

Can I make a hole in a touch screen without ruining it?

I need to make a big capacitive touch screen with holes inside it, can this be done without ruining the whole screen? Thanks in advance.
0
votes
1answer
35 views

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 ...
-2
votes
2answers
45 views

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.
0
votes
1answer
45 views

PIC16F1827 Capacitive Touch Sensor not Incrementing Timer?

So I have a PIC16F1827 on a breadboard and was trying to get a simple demo working where I touch a wire to turn on an LED using the Capacitive Sensing Module. I was primarily going off this example I ...
0
votes
1answer
26 views

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 ...
0
votes
0answers
43 views

How to design a capacitive power supply with 4v battery backup?

I want to make a simple and cheap LED driver with a backup battery on mains failure. The battery (4v Lead Acid) should be protected from overcharging. Problem Would this circuit works? (what are the ...
0
votes
1answer
45 views

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 ...
3
votes
2answers
184 views

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 ...
0
votes
1answer
81 views

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 ...
5
votes
2answers
187 views

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 ...
0
votes
2answers
44 views

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 ...
1
vote
0answers
173 views

Raw data acquisition from a capacitive touch screen

I'm trying to integrate an existing PCAP touch screen into an experimental project I'm working on. For it to work the way I want, I need access to the raw data from the touch-screen nodes instead of ...
0
votes
1answer
100 views

Increase Measurement Distance of a Capacitive Proximity Sensor - Arduino Project

So I am working on a project that I found online at (https://makezine.com/projects/a-touchless-3d-tracking-interface/). However, instead of using my hand to track, I want to track an aluminum ball ...
1
vote
1answer
122 views

Capacitive fluid level sensor design and insulation

This is a question regarding the measurement of a fluid level (in my case water) using a capacitive sensor. Capacitive sensors are a common topic, but I have one specific question: It is necessary for ...
0
votes
1answer
56 views

Using capacitive touch switch as guitar pick-up selector

I want to use two Schurter 3-101-401 one for each pick up. I was able to get them wired up but the signal for the pick-ups comes out no matter what. Here is the info https://www.mouser.com/...
1
vote
0answers
137 views

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}+\...
1
vote
3answers
388 views

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 ...
0
votes
0answers
69 views

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. ...
1
vote
1answer
96 views

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 ...
1
vote
2answers
379 views

What is the best oscillator to be used in a capacitive soil moisture sensor?

I am working on this project where I am going to make a soil moisture sensor. The principal that I'm going to use is the change of capacitance of the soil with moisture. What I'm going to do is make a ...
0
votes
0answers
43 views

Low coupling capacitor of a SEPIC / ZETA / CUK for Wireless Power Transfer using coupling capacitance

I am studying a converter, which is a modified version of a Buck-boost, which is basically a SEPIC converter with very low coupling capacitance. The low capacitance comes with the need of wireless ...
1
vote
1answer
160 views

How can I build a touchpad/trackpad?

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 ...
0
votes
1answer
70 views

capacitive power supply design query

I was trying to make an LED lamp with 16 series 3528 SMD LED chips. I am planning to use a transformerless capacitive power supply to step down 230V. As per my calculation 16 led will require the ...
0
votes
2answers
289 views

Soil moisture sensor - Interdigital (FEF) vs Coplanar

I am working on the development of a low cost capacitive soil moisture sensor which uses dielectric permittivity changes to estimate moisture. I found that interdigital capacitor based on FR-4 has ...
-2
votes
1answer
398 views

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 ...
2
votes
1answer
79 views

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'...
0
votes
0answers
45 views

Is it possible to interact with a capacitive touch screen through a 25 meter wired connection?

I’m looking to create a device that snaps onto an iPhone with a 25 meter wire. When a person touches the wire from 25 meters away, it will effectively tap the screen. Ideally, this is passive, ...
1
vote
1answer
71 views

Noise due to stray voltages in a data acquisition system

A single ended earth grounded data-acq. board on the left in the below illustration has inputs coupled by BNC cables coming from force transducer amplifiers A1, A2, A3, A4 as shown on the right: If ...
0
votes
1answer
184 views

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 ...
1
vote
3answers
116 views

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 ...
0
votes
0answers
103 views

Current limitation to capacitive voltage divider

For an AC capacitive voltage divider, I would think the amount of current that could come from the divider would be limited by the absolute size of the capacitors. The flow of current should be a ...
0
votes
1answer
242 views

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 ...
0
votes
0answers
122 views

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. ...
1
vote
1answer
197 views

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-/...
-1
votes
2answers
330 views

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 ...
2
votes
1answer
244 views

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 ...
1
vote
0answers
99 views

Identifying a component and its purpose in capacitive touch circuit

I got a chance to tear apart a touch sensor that comes from some chinese vendor. I was able to figure out the touch controller IC and find a datasheet for it. Datasheet of touch IC However, the pcb ...
0
votes
3answers
147 views

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 ...
1
vote
1answer
114 views

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 ...
1
vote
2answers
766 views

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 ...
0
votes
1answer
117 views

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 ...
1
vote
4answers
133 views

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 ...
3
votes
1answer
315 views

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 ...
0
votes
0answers
486 views

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 ...
3
votes
2answers
353 views

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 ...
0
votes
1answer
221 views

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), ...
3
votes
1answer
489 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 ...