Skip to main content

Questions tagged [capacitive]

Based on the usage of capacitors, condensators. Alternatively, utilizing the derivative of signals.

Filter by
Sorted by
Tagged with
0 votes
0 answers
16 views

How can I make an effective head-mounted pointing device for a touchscreen

I have read How can a capacitive touch screen be triggered without human contact? and feel a bit closer to understanding the technology, but I am still a bit puzzled. I recently picked up the task of ...
bodgesoc's user avatar
  • 101
1 vote
3 answers
73 views

Purpose of electronic elements in a capacitive dropper circuit

I have found a capacitive dropper circuit in an LED light bulb: I have a few questions about this circuit: Normally, in capacitive dropper circuits, I would expect a resistor parallel to C1. I am ...
MasterMind's user avatar
1 vote
3 answers
210 views

Sine wave CMOS buffer from inverters with or without feedback

Is it possible to buffer a sine wave using inverters alone or with some kind of feedback? I've been browsing google for minimalistic (I'm in 3.3-12 V domain) sine wave buffers and this thought stuck ...
San's user avatar
  • 85
0 votes
1 answer
98 views

How to simulate a finger touch electrically to remove noise

I am working on a project with "SIM800L" GSM module, the problem is that there is a noise from the module in the calls and it disappears when I touch the module's body with my hand. Kindly, ...
Mohamed Essam's user avatar
0 votes
1 answer
90 views

High voltage pad buffer design with 2nF load and ringing on first stage output

I am trying to design a high voltage (12V) buffer that will drive a sine wave with rail-to-rail peak-to-peak amplitude and a big capacitive load, maybe 3nF. Browsing I came upon this Master's project: ...
San's user avatar
  • 85
2 votes
1 answer
79 views

Current slew rate specification of op-amps?

I know that slew rate specifies how fast the output voltage of an op-amp can change. But is there a measure that specifies how fast the output current of op-amps can change? I need this information ...
Mustafa Turhan's user avatar
2 votes
2 answers
104 views

Vintage capacitive switch

I have this switch from a Philips Electronic 212 turntable. It’s simply two metal pieces, one a ring and the other a button-like center. I’m not sure, but I think it is a capacitive sensor or button. ...
acanessa's user avatar
0 votes
1 answer
58 views

Time delay circuit to reverse the rotation of DC motor when input is high

I am trying to design a circuit to use to control a DC motor according to the output of a capacitive proximity detector. The circuit should turn ON the DC motor in forward direction when the hand ...
Shamooooot's user avatar
0 votes
0 answers
46 views

Connecting GND to PE to improve touch sensors sensitivity

I am designing a smart light switch based on a microcontroller, with touch buttons. The design consists of two PCBs: a low voltage one for power (230 V) and an extra low voltage one for control (3.3 V ...
Elzaidir's user avatar
  • 103
1 vote
0 answers
82 views

Convert capacitive sensor into physical button?

Is it possible to turn a capacitive button in to a protruding mechanical one? I am thinking something round that sticks to a surface with a capacitive button on it and is essentially just a button ...
Locane's user avatar
  • 111
0 votes
0 answers
49 views

Measure capacitance on a mutual capacitive touch sensor

I interpret the mechanism of a mutual capacitive touch sensor like this: There are 2 electrodes X and Y. To measure the difference in capacity, the X electrode is driven high (i.e 3.3 V) and the Y ...
Maze2Go's user avatar
1 vote
1 answer
78 views

Looking for a large capacitive touch array controller

I'm building a capacitive touch panel. It has an odd shape, so I resulted to building my own with the capacitive diamond array solution. It doesn't have a screen underneath, so it's all contained on a ...
Tamás Fehér's user avatar
0 votes
0 answers
23 views

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 ...
Andrea Scarpellini's user avatar
3 votes
2 answers
612 views

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 ...
sharkyenergy's user avatar
2 votes
1 answer
104 views

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) ...
ACBlue's user avatar
  • 75
0 votes
0 answers
39 views

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 ...
Kirill Kulakov's user avatar
1 vote
5 answers
760 views

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?
I am LOSER's user avatar
1 vote
1 answer
61 views

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 ...
Igcasan's user avatar
  • 11
0 votes
2 answers
108 views

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 ...
huababua's user avatar
  • 115
1 vote
2 answers
124 views

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 ...
Mustafa Turhan's user avatar
0 votes
0 answers
169 views

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 ...
Frank's user avatar
  • 15
1 vote
1 answer
219 views

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 ...
Zanius Maximus's user avatar
0 votes
2 answers
679 views

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 ...
Rodrigo's user avatar
  • 567
1 vote
0 answers
35 views

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 ...
Thien Ho's user avatar
-1 votes
1 answer
49 views

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 ...
anndress07's user avatar
2 votes
2 answers
180 views

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 ...
RobMcN's user avatar
  • 165
4 votes
2 answers
2k views

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 ...
JoeyB's user avatar
  • 2,389
2 votes
1 answer
491 views

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 ...
Sod Almighty's user avatar
  • 1,465
0 votes
1 answer
69 views

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 ...
Lorenzo Marcantonio's user avatar
0 votes
2 answers
321 views

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 ...
Jonas Daverio's user avatar
0 votes
0 answers
438 views

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 ...
Buffoon's user avatar
  • 11
0 votes
1 answer
98 views

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 ...
GUI's user avatar
  • 1
0 votes
1 answer
213 views

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 ...
DINEDINE's user avatar
  • 103
2 votes
2 answers
298 views

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....
H0li Ravi0li's user avatar
0 votes
1 answer
1k views

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 ...
yolt's user avatar
  • 113
0 votes
2 answers
101 views

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 ...
InBedded16's user avatar
  • 1,010
1 vote
4 answers
373 views

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% ...
HandlerOne's user avatar
3 votes
1 answer
772 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 ...
JackOfHearts's user avatar
0 votes
2 answers
564 views

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 ...
johnnydanger's user avatar
0 votes
1 answer
57 views

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 ...
rockstar's user avatar
0 votes
1 answer
438 views

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 ...
Burak Bozdoğan's user avatar
1 vote
0 answers
106 views

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 ...
Rocketmagnet's user avatar
  • 27.5k
0 votes
0 answers
62 views

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 ...
moscardo's user avatar
0 votes
0 answers
322 views

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 ...
Mohammed Aman's user avatar
-1 votes
1 answer
231 views

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 ...
Vikas Acharya's user avatar
2 votes
1 answer
128 views

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 ...
John Earley's user avatar
1 vote
3 answers
2k views

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 ...
Dr_Smu's user avatar
  • 21
0 votes
2 answers
75 views

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 ...
Brandon Ramos's user avatar
0 votes
2 answers
94 views

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 ...
UsernameError's user avatar
0 votes
0 answers
124 views

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 ...
Lan Tran's user avatar

1
2 3 4 5 6