Questions tagged [floating]
A voltage that is not connected by any conducting path (including resistors) to ground or the key voltage reference point.
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Is it possible to "stack" the outputs of 2 or more buck converters?
Is it possible to "stack" the outputs of 2 or more buck converters?
The buck converter circuit in question I am considering is the 48v to 5v typical example circuit from page 20 of the ...
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Randomly Floating PWM signal
I am having trouble with a randomly floating digital signal. Transmission is between a microprocessor and a CPLD unit and is used to run a half bridge. Measurement was taken after the output resistor ...
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Random activation of transistor base by capacitive coupling (ghost voltage)
I have a smart module used for home automation. It is equipped with two relays, a wifi mcu, and two switch input.
For the switch input it uses AC mains detection using transistor (non-isolated.)
In ...
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Why does an LED remain glowing when MOSFET gate is open?
Hello,
I'm working with an N-Channel MOSFET (Link to data sheet for the MOSFET - https://www.onsemi.com/pub/Collateral/FQU13N10L-D.pdf) for the first time on a DC motor project, and I'm trying to ...
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What does "Default Output State" mean for a digital isolator?
I do not understand the term "Default Output State" of the SI8422AB-D-IS
digital isolator. I saw it on this datasheet at page 3:
Does it mean "the default output voltage if the input ...
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How do actively driven mosfets or transistors react to floating source?
Attempting to add some lights to a car's "intelligent" lighting system. Want to make sure I understand how my n-channel mosfets will react to losing their ground, while their gates are still connected....
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How do floating voltages affects circuits/systems?
I was at a talk recently regarding robustness testing. It was separated into parts: Uncontrolled and Controlled.
Uncontrolled involved applying high floating voltages to various pins and logging the ...
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Can I leave it unconnected pins in the level shifter?
My concern is that pins are connected between DB25 and TXS0108E, but are not connected between TXS0108E and the Header 5x2. There is only the tracks between TXS0108 and the Header 5x2, but there is no ...
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Strange floating base NPN behavior
I'm learning about NPN transistors and have wired up this:
I understand some of its behavior, but one is a complete mystery for me.
First, if I tie "B" (green dangling wire) to "G"...
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Dc power supply outputting sine wave at both terminals
I connected a DC power supply (set to 706mV) to a 1kohm resistor as this:
The semantic is like:
However, strange things happen when I use the oscilloscope to view the voltage waveform at point A and ...
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Pulling the circuit's voltage to the ground with grounded probe
When measuring a point on an isolated circuit board with my grounded oscilloscope, I fear my oscilloscope ground will pull the measured point to ground level but this has never happened, I am always ...
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No unconnected inputs yet ICs (logic gates) still seem to yield erratic/odd behaviour
I just finished building a 4-bit adder on a breadboard and I am experiencing some quite odd/erratic behaviour and I am wondering why. The actual circuit/logic works as intended, meaning the 4-bit ...
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Understanding Differential Mode Voltage of a Floating Circuit?
I am currently trying to work on studying for the ECE NCEE FE exam, but I came across the problem and don't quite understand the answer.
Essentially we have an ideal transformer with an arbitrary ...
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Floating Differential measurement?
Can I simply hook up an opamp inputs, (either using a differential or in-amp topology that is/are also powered from a floating power supply), across a device under test that itself has exceeding ...
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What is the correct way to bias a floating instrumentation amplifier?
Im designing a voltage measurement circuit that needs to measure differential signals in the order of mV in the presence of high voltage common mode noise.
Im using a isolated DC/DC converter that is ...
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Why is this capacitive circuit not working in both multisim and LTspice
The voltage at the top most node of this circuit should be the average of the input voltages.
Vtop*CT = C1*V1 +C2*V2 +C3*V3 where CT = C1+C2+C3
I get 0V instead.
UPDATE
Thanks for the help. I ...
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Floating input pin with external pull-up
I would like to improve the performance of my push buttons, which sometimes don't respond when pressed. They have external pull-up resistors and have been initialised as floating input pins. Does not ...
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Floating analog input of ADS1115
I am using an ADS1115 as an analog to digital converter.
R2 and C2 are used as a low pass filter. I have used two schottky diodes as voltage clippers to protect against over voltage. To avoid ...
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Floating traces on MCU dev boards bad for noise?
When you have development boards for microprocessors with every GPIO pinned out on headers around the edge of the board, is the board more susceptible to picking up noise than a board without all ...
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How does a pull-down prevent a "false 1" in a pin?
yesterday I asked a question about pull-ups and pull-downs and resistance in an input pin, but I feel that the question that invaded me today is different from my yesterday's post so this is why I'm ...
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Floating battery negative terminal [closed]
I am building a circuit that uses an op amp comparator stage to control the circuit shown.
The op amp circuit will switch on or off the transistor to drive the motor supplied with a set of AAA ...
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Floating Simulated Inductor
In the image below, I do understand that a grounded inductor can be simulated using op amps. However, to make a floating simulated inductor, I have read some posts that said two ground simulated ...
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Floating Nodes Error in Simulation in ORCAD PSPICE
Does anyone have any insight as to what exactly is wrong with my circuit on Orcad/PSPICE?
My name is in the project name so I blurred it out for obvious reasons
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Battery powered device - How to measure external floating differential voltage
I have the following task. As depicted in the sketch, I have a battery powered device which needs to measure the differential voltage VIN between two external nodes, EXT_NODE1 and EXT_NODE2. It is not ...
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What is the result of 1 and float on OR gate?
If only one input is 1 into an OR gate, the output is 1, but does that still count if there is no input from other sources? (like float) Or is the output simply float as well?
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multiplexer with floating outputs
I have actually a solution based on a multiplexer (CD4051) which drives 8 outputs, either at 0V or 3.3V (the input is at 3.3V). Each output of the multiplexer drive a NMOS and the goal is to have a ...
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Why does my ungrounded DC power supply work?
This is a question about electronics theory that I haven't been able to grasp. I was testing a stepper motor wired like the following: https://learn.adafruit.com/adafruit-tb6612-h-bridge-dc-stepper-...
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EMC - conducted emissions - unused wires in cable - puzzling coupling
I am trying to understand the impact of unconnected wires in a cable for EMC conducted emissions tests.
My product has a shared unshielded cable for supply and communication (I know it's bad practice....
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Sensing of AC current. Isolation Capacitor Problems?
I want to measure the AC Current flowing through a Piezocrystal (replaced in the circuit with a resistor) being driven by a TI DRV2700. http://www.ti.com/lit/ds/symlink/drv2700.pdf
This Chip puts out ...
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Unused/floating pins on BTS5016
I plan to use Infineons PROFET BTS5016 in a coming project.
https://www.infineon.com/dgdl/Infineon-BTS5016-2EKA-DS-v01_00-EN.pdf?fileId=5546d4625a888733015aa41a5e161129
I will not use the ...
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About floating ground and circuit problems
Good morning,
I have a power supply with floating ground that drives my circuit.
Since the circuit doesn't work as expected (it works fine only if the ground is tied to earth) I did some measures with ...
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Is a floating pin equivalent to a very weak pull down?
I know that if a MCU pin is configured as "input" and it is not connected to any pull up/ pull down resistor, it is said to be floating.
In this situation, we could say that the pin is in series with ...
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Why can a MCU input floating pin easily change state?
I would like a technical ("engineering") explanation of why a MCU input floating pin can easily change its state depending on the outside electromagnetic interference.
Is it related to the fact that ...
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How to handle disconnected resistive sensor?
I'm trying to connect a PT100 thermo probe to an Arduino project to measure water temperature. After some research I have found and adopted a design using a Wheatstone bridge and an instrumentation ...
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Is it possible to get a floating power supply to power multiple MOSFETs
Hey guys this is my first post on stack exchange so please go easy on me!
I have a hobby project where I was trying to make a few batteries go in series using a micro controller and a floating power ...
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Micron NOR unused pins have pull-ups. Any danger just leaving them there?
I have a board designed for a dual-die Micron MT25QL512 QSPI NOR flash. These parts are in short supply, but the board fabricator had some single-die MT25QL128, and used them instead. The single-die ...
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Floating Power Supplies
Referring to this post, is it possible to float power supplies by simply not connecting the ground wire?
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Constant Offset Floating Supply
What circuits can be used to provide a voltage supply capable of sinking around 1A of current that will always float 10ish volts below a given supply, that could be from 12 to 200 volts?
I have ...
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Measuring small currents at DC high voltages without floating meter
I'm doing a project with a Cockcroft-Walton multiplier that will output up to 40 kV DC at up to 10 mA. The the circuit takes an input of 10 kV AC at 60 mA and 60 Hz (from a neon sign transformer) and ...
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How can I float a pin that otherwise should be low?
I want to enable/disable a TI TPS54302 buck regulator with a microcontroller. The enable (EN) pin should float to enable the device, or be tied low to disable it.
I currently have the EN pin ...
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What is the right way to float a home lab?
I just got myself some new toys for my lab at home like 30V DC power supply, KKmoon signal generator and a Rigol DS1052E. I want to float everything, because I don't want to spend any money on stuff ...
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Consequences of leaving unused inputs of clock buffer floating. Alternative: best practice
I'm using a Si53342-B-GM
Original datasheet download at silabs for the si5334x-series
as a clock buffer.
In some cases I only need to distribute a single clock signal and in some of my cases I ...
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Why does a pull down resistor eliminate floating input
Ever since I connected a button to an Arduino for the first time, I've wondered how does the resistor prevent floating input from happening? I've read several answers to similar questions, seen videos ...
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Floating input in Op-amp Readout Circuit?
I was analyzing this circuit diagram in a thesis about a capacitive EEG electrode. The author talks about a flaw in the design where there is a "floating analogue input" that is causing the op-amp to ...
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Isolated power supply with output on a 2kVDC floating ground
I am building a system of detectors which are referenced to independent floating grounds. The maximum voltage between each stage is 2kVDC. So I need isolated supplies which can operate continuously at ...
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Floating neutral in TN-S or TN-C-S earthing system
Since neutral is bonded to ground at building distribution point in a TN-S or TN-C-S earthing system, could floating neutral happen under the following conditions:
Loss of N and/or PE at transformer
...
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Design for a balanced (positive and negative) HV DC regulator
I'm trying to design a high voltage DC regulator for driving a PZT that will provide both +200 and -200 V outputs referenced to ground. The input is a rectified AC waveform that will provide UK mains ...
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Why are the dimensions of a floating gate layer in a MOSFET so thick?
For a floating gate MOSFET, in order to make the control gate work you have to(generally speaking) make the oxide layer thin(~100 Angstroms) as well as the ONO(Oxygen nitride, acts as an insulator) ...
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Confusion about the meaning of floating
Here they define being floating as:
They mention Ungrounded = Floating.
But in another forum someone wrote:
The signal is consider floating when it does not have the same ground
with your ...
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Floating DC power supply (solar panels) - do I need double-pole breakers and why?
I am in the process of building a small off-grid solar setup.
There will be 4 parallel strings of panels in this setup, and I understand that for 3 or more strings, you need some sort of over-current ...
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