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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3answers
372 views

Can a 1:1 transformer prevent the SMPS noise of one load from reaching other loads plugged into a mains outlet?

It's my understanding that a load which has a SMPS can put noise back onto the power cord, which could reach another component that's plugged into the same outlet. Is it true that a 1:1 transformer ...
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397 views

Who do IGBT rectifiers have floating gates (unlike MOSFET rectifiers)?

When I search Google Images for "IGBT rectifier", I notice that they all appear to have floating gates. But don't IGBT's have gates like the ones on MOSFET's, in which it's insulated from the other ...
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2answers
824 views

How to check if pin is floating or connected to ground?

I am using a DC jack which has 3 pins. 2 for power and one pin which is connected to ground when there is nothing plugged into the jack and disconnected from the ground when the jack is plugged in. ...
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92 views

Do I need PSUs with similar current rating when I connect them in series?

I need a 48V power supply with 20-25A so I decided to use old ATX power supplies I have lying around. I know already that the series of ATX PSU can be used to charge lithium packs for RC planes, it ...
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3answers
2k views

{IC pins} Leave Floating vs Leave Open?

This might be a newbie question, but I have always heard these terms interchangeably and never given it another thought. Recently I have seen them used differently in data sheets for a board I am ...
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2answers
319 views

Noise pickup in fully floating circuit

I'm using an ac coupled noise matching transformer to measure the voltage noise of a low ohmic sample as a function of bias current. The complete circuit is in an enshielded enclosure. When the ...
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2answers
480 views

Floating voltage on metal shelf

I just setup a pepper seed starting shelf using a metal shelf from a Swedish furniture outlet. The shelf has no electrical contact with the 5x T8 bulbs which are hanging on plastic zip ties. The T8 ...
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1answer
77 views

Using a DAQ with a programmable power supply floating input

I have a programmable power supply (Sorensen DCR300-16T) that requires a floating programming voltage. From the manual: (3.9.1) In selecting a signal source, the following should be considered: ...
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1answer
147 views

Floating inputs and Vref on a voltage subtractor (PWM to Gate converter)

A little background: I'm trying to extract a gate signal from someone else's circuit (ckt1) so that I can synchronize events in my design (ckt2) to a sequential trigger in theirs. First problem is I ...
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5answers
1k views

How is the input not floating when there is a pull-down resistor? [duplicate]

I am wondering why the input to D2 will not be floating when the switch is open. If the switch is open, wouldn't it act like a mini antenna and provide a random input to the D2 pin?
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175 views

What are the risks of running a floating ground through insulated wire underground?

I've created a circuit that is powered with a floating ground off of a transformer. I'd like to count pulses from a meter by having the meter complete the floating ground side of the circuit but I'm ...
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1answer
1k views

Connecting Two Grounds Together

I'm trying to understand what would happen when connecting two grounds from diffident power supplies together. A more in depth explanation of what I'm trying to accomplish is here: Connect Arduino to ...
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3answers
586 views

Understanding microcontroller ADC input pins (atmega328)

If I set up the ADC on the ATmega328 to read from a certain ADC pin, what state is the ...
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4answers
2k views

Why would you need a floating signal on a board?

I read the following from a book titled "An Embedded Software Primer" by David E. Simon. (23rd print Nov/2014 - Page 16) If no part on the circuit is driving a signal, then that signal is said to ...
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1answer
755 views

How to prevent floating input for this system?

I have a simple system where a motor speed is controlled by a voltage signal via a circuit. Below represents the system where A is the voltage signal device; B is the circuit and M is the motor. The ...
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1answer
74 views

What would I expect to read from a disconnected SPI port?

I'm writing a program that reads from a SPI port. However, there's some complicated logic that controls whether the slave is physically connected to the port (if not, the lines are left floating). ...
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2answers
543 views

Why do we use pull up resistor with PIC?

I tried to find an appropriate answer for the question but couldn't find what I needed exactly. I found out that "Initially the output from the PIC is floating and we use the pull up resistor R7 to ...
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3answers
728 views

Are capacitors floating power supplies?

I'm struggling with the concept of floating voltages. For a grounded supply I can connect one side to an effectively infinite ground and get full power. It may vary depending on its construction, ...
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1answer
3k views

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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2answers
1k views

2N7000 behaviour explanation

I recently bought a 2N7000 transistor and though it was a cheaper replacement MOSFET compared to the STP55NE06 as I didn't need to handle high voltages and high currents. However it acted very ...
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1answer
104 views

Provoking Floating Port

I have a floating pin / port on a micro controller. I want to show that the maximum additional current from this pin is above a certain safty threshold. Can I somehow provoke the pin to draw ...
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1answer
545 views

What is the purpose of transistor and zener in this circuit?

simulate this circuit – Schematic created using CircuitLab (simulation will not be correct because the diodes are added just by its name.) Hello, I am a student who is not really familiar with ...
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2answers
448 views

Floating value when connecting to IC input

I'm currently having a strange issue with what I think is a 'floating' signal. The setup: I have a bank of inputs (which are connected to a resistor and LED acting as a pull-down) connected to inputs ...
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1answer
290 views

FPGA input pin internal floating

I am now occouring a FPGA pin damage problem. One of my pin is hardware connected to a 1.8V signal that will be switched on/off occasionally, while the port is not connected to any other logic gate ...
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1answer
189 views

FPGA + SRAM - floating inputs of SRAM during configuration of FPGA

I'm connecting SRAM to FPGA (Spartan 6). During configuration and during periods when FPGA will be down (for example I would like to turn off FPGA when external flash will be programmed by uC) address ...
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3answers
1k views

How to check if a DC power supply is a floating source?

Imagine a laptop power supply with 2 prongs and I'm using this as a power supply for a circuit, and the output of this circuit is an input signal Vin for a data acquisition hardware. How can I ...