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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Float division in verilog
I'm trying to implement a basic sigmoid function in verilog. But I'm having a problem with float division, I don't know to make it not truncate. I think the code is doing an integer division and I don'...
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I am driving a LT3092 current source with a variable voltage - to get a variable DC current, but the output needs to float 0 to 1.5V above ground
What type of buffer amplifier would work - either discrete opamps or a differential output opamp? The output voltage would ideally vary up to 12VDC. The variable current source has a variable load ...
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What is the safest and most noise free grounding method floating or non-floating for audio plugs & circuits on 2U aluminum case and SMPS
I have read countless documents and viewed schematics on this subject but am still confused when it comes to physically building a box and running all of the wires correctly and safely.
I drew a very ...
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Why is the voltage across the 30 kohm resistor taken as 6 V? Is it something to do with the fact that it is a floating voltage source?
Why is the voltage across the 30 kΩ resistor taken as 6 V? Is it something to do with the fact that it is a floating voltage source?
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Circuit that holds a PIN to GND and leave it floating after power on
I need a simple circuit that during power on fixes a pin of an IC to GND and after a while leaves this pin floating.
Another circuit should be the same, but fixing another pin to -VEE (-30 V) and then ...
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What issues can floating nodes cause?
I recently asked a question on why my naive implementation of a XOR circuit in CMOS was wrong.
One of the most mentioned issues was that I had a floating node in my diagram. I've looked up floating ...
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MCU floating pins
You'll have to excuse my ignorance I'm learning as I go along.
I would like to use a switch to toggle the state of the ESP32_EN pin in the schematic from high to low, however the pin can not be left &...
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Coupling floating differential inputs to an amplifier with/without resistor pair
My question is about wiring a "floating differential input" signal to an instrumentation amplifier.
I've read that in the case of a floating signal two high value resistors are used to ...
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Mains: If I measure 30 VAC on a switched-off circuit, is it more likely that one wire is floating or "partly energized"?
It's a 3-way switch circuit powering an LED light bulb. I don't know how possible it is for a wire to be partly-hot at some level between 0 and 110 V. I know that floating voltages show up as ...
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How do floating voltages actually work?
First of all, I do not have any electrical / electronics background, I am just a self-taught, so there are very high chances that this question does not make any sense at all. Sorry in advance if that ...
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Texas Instrument OPA192
I'm examining the datasheet of the OPA192. When the inverting input of op amp tied up the op amp output and if the non-inverting input of op amp had been floating, what would have happened the op amp ...
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Why does this active-low relay work when floating?
I have the following circuit:
simulate this circuit – Schematic created using CircuitLab
When I digitalWrite(HIGH) the GPIO pin, the transistor closes and ...
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Which consumes less current in microcontrollers: Always HIGH pins or always LOW pins?
I am driving a P-MOSFET (IRLML6402) with ATtiny24A microcontroller. This is a battery powered system; that's why ATtiny is always on sleep. I originally configured a BJT which is driven by the ...
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Capacitor to earth in floating power supplies
I'm looking at using two separate, floating supplies in a 20W power amplifier design to generate +24V, 0V, and -24V low-impedance rails. Some research suggests this is doable, and seems much less ...
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ESD damage without earth ground
Can you explain how a totally floating PCBA (with semiconductor chips/ components stuffed, but no any connection to earth GND) is damaged by an ESD event from human touch?
If human body is charged to ...
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How to drive multiple floating N-channel MOSFETs
I want drive a RGBW-LED (CREE XLamp XM-L) using a synchronous constant current buck. To control the brightness and color, the LED of each color channel is controlled by a shunt transistor using PWM.
...
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Microchip FPGA Internal Short Circuit
We are using the FPGA ProASIC3E A3PE1500-PQ208. The FPGA got internally short circuited during runtime. The FPGA IO Supply Voltage and FPGA ground are permanently short circuited and it is not ...
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Vl53l0x ToF Sensor turn on without gnd
My ToF sensor turn on if I not connected its ground pin to common ground (I let it float). Why?
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Tying open-collector outputs to TTL inputs
I know that open collector outputs are effectively either 0 V or high-Z.
I also know that TTL chips tend to read a disconnected output as high, but that really you should have something like a 1 kΩ ...
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Why is the voltage across high impedance indeterminate?
The analog pins on my Arduino read sporadic values when unconnected, and my multimeter (set to VDC) shows random values when there's no connection between the probes. If I connect the analog pins on ...
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Do disconnected input pins act as “antennas” capacitors that get gradually charged, building up higher and higher voltage?
Disconnected input pin acts as an antenna affected by surrounding electromagnetic noise, and can "float" between on and off. Does the input pin also act as a capacitor that gets gradually ...
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Are there logic gates by which a signal could propagate backwards?
Is there a type of logic gate with floating inputs (I'm using that term loosely) such that a fixed voltage on an output could "propagate backwards?" Let me clarify with examples...
Say you ...
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Counting signal switching between floating and LOW in Arduino
I have a rotating contact (contact breaker of an ICE) that switches between being not connected to anything (floating) and being connected to the case of the ICE. The engine case is connected to ...
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Bias tee for floating DC supply
I have a floating DC low noise current source driving a load. I also need to drive this load with an RF source but the grounds are not referenced to each other so I don't think I can use a standard ...
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Connecting GND on secondary side to protective ground
We have a battery powered equipment which mainly consists of a temperature sensor connected to a microcontroller via a filter. In addition to battery power we have now added the possibility to use a ...
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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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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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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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Floating voltages and current path between isolated circuits
I have a bit of trouble understanding floating voltages. I thought about quite a few circuits and scenarios involving isolation transformers and floating voltages but something is still off.
Here are ...
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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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Confused about opamp's inner "ground"
(well. I am NOT speaking of "virtual ground" throughout this question/)
As this figure has shown an opamp can be viewed as:
We all know that an opamp like this has two inputs and one output ...
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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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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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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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How to get rid of floating voltage on Bridge rectifier
I'm trying to implement a rectifier and AC voltage sensor. The rectifier part works just fine. I'm able to power my device without any issues.
Please look at C2 in the screenshot (Circuit schematic)....
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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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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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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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