Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [ground-loop]

For questions about ground loops, which occur when multiple ground nodes in a circuit (which should be at the same potential) actually have a potential difference between them. This is usually caused by a significant current flowing between the ground node(s), thus producing a voltage between them. Ground loops cause various problems in a circuit.

For questions about ground loops, which occur when multiple ground nodes in a circuit (which should be at the same potential) actually have a potential difference between them. This is usually caused by a significant current flowing between the ground node(s), thus producing a voltage between them. Ground loops cause various problems in a circuit.

See Wikipedia's article on ground loops for more information.

273 questions
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To "ground fill"or not to "ground fill"?

I have been reading up on the EMI issues in Electromagnetic Compatibility Engineering by Henry Ott. (wonderful book btw). One of the topics "PCB Layout and Stackup" (aka Ch 16) there is section about ground fill (16.3.6). Basically what it states,…
Wally4u
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Why is this resistor connected between connector shield and ground?

I was looking over my raspberry pi model B and I noticed a resistor between the USB power connector shield and ground. I've noticed this on many PCB designs with much larger packaged resistors although I've never known the reason for them. This is…
Funkyguy
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How to design a schematic and PCB for an ADC using separated grounds

I want to measure a DC voltage with very high resolution (uV) and send the value to a PLC (based on an Arduino Mega.) Initially I selected an ADS1115, but I got some power noise due to loop currents (discussion in this question). I decided to…
bardulia
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Why we use ground

I have been wondering this for a while, so I did some digging, and as usual, wikipedia was the most illuminative. It looks like the telegraph was the first time ground was introduced to complete a circuit. It seemed to have been a good idea to save…
Alex Eftimiades
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Shielding and Ground loops

I have various pieces of equipment that all need to be connected to GND (Chassis GND). The issue I'm having is that I'm connecting an ADC card inside a computer through a metal box with custom electronics that connects into a cryostat (metal…
Ross W
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Grounding of ADC grounds

Fast, high resolution ADCs, especially ones that have parallel output, usually have a separate supply pin (DRVDD, (drive vdd) or OVDD (output vdd)) presumably because they don't want to couple noise to the sensitive analog supply while all the…
SomethingBetter
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Single point vs Ground plane, in audio OP AMP PCB layouts

Recently I had posted a seemingly innocent question on another forum. I was trying to keep a small and relatively simple circuit down to a 2 layer board and was asking about the shielding merits of a copper pour tied to analog ground, as opposed to…
Randy
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Why does analysis indicate that ground lifts do not fix ground loops?

Note: "Ground loop" in this question refers to a ground loop caused by linked magnetic fields. (Sometimes ground loop refers to slightly different scenarios.) Recently I've been looking into ground loops a lot since I've encountered them in circuits…
PersonWithName
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Is this a case of ground loop?

I'm trying to power a 24V DC motor using 2x 12V batteries, an Arduino and a Cytron MD10C Motor Driver. I followed the description on Cytron's website for how to connect the Arduino and the motor to the driver board. The 2 batteries are plugged in…
Alex Clement
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Power supply noise in audio

I have what is surely a classic problem with regard to power supply switching noise and audio but I am unable to sort myth from reality with regard to what I found so far on the topic. Setup: I have a notebook with an external power suppy and/or…
ARF
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Communication between microcontroller and separately powered PCB

On one board I have a microcontroller with one power supply and on another I have a Flip Flop with a separate power supply. I want to connect a pin of the microcontroller to the reset pin of the flip flop. Can I just put a wire accross or does it…
Ayeayeron
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Are loops in ground planes acceptable?

Working on a PCB layout and just did some ground plane pour. From working with tube amplifier designs I know that a good star shaped ground design helps a lot to keep hum out of the circuit. Ground loops should be avoided at all costs. Now here is…
Nils Pipenbrinck
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Can I use ferrites for the ground connections?

I may have an issue with conducted EMI through the ground connections between devices in a system. There is specifically a device which clearly creates noise on the measured signal from another circuit with a scope (noise is reduced when it's off).…
Joan
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Isolating audio ground between devices

I'm planning a build for a guitar amplifier with 2 stages, the first being a tube pre-amp and the second stage being a solid state amplifier. Both amplifiers will be powered from the same source, a 31v DC power brick. The pre-amp will be powered…
Jim Valentine
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Closing loops or not? - supply lines on a PCB

When routing a Gnd line, I wonder if it's best to keep loops open, like so:   or to close the loop, like so: I could think of some arguments in favor of closing the loop: PRO Looping arguments: Coupled magnetic fields try to create current (by…
K.Mulier
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