Skip to main content

Questions tagged [grounding]

Problems related to the connection of circuits to ground or earth references. Can affect safety, accuracy, reliability and interfacing.

Filter by
Sorted by
Tagged with
14 votes
1 answer
9k views

Analog & Power Ground Planes Doubts

Working on a new board, I have to face some requirements to ensure the performance of the whole system once is manufactured. PCB is a 4-layer one, and it has both analog and digital components. But ...
Yolco's user avatar
  • 367
138 votes
6 answers
66k views

Should chassis ground be attached to digital ground?

I'm working on a PCB that has shielded RJ45 (ethernet), RS232, and USB connectors, and is powered by a 12V AC/DC brick power adapter (I do the 5V and 3.3V step down on board). The entire design is ...
cdwilson's user avatar
  • 1,753
39 votes
5 answers
37k views

Why don't we use neutral wire for to ground devices and earth wire for closing the circuit?

I know that the neutral point of a distribution transformer is connected to the grounding (earthing) wire, so I think they are the same. Can I use the neutral wire for protecting metal-cased electric ...
Michael George's user avatar
80 votes
11 answers
42k views

Why on earth are o-scopes earth referenced?

Thinking about it: You would never find a "Grounded" multimeter as robust and useful if a path to ground through the multimeter were introduced, modifying the circuit's behaviour and possibly damaging ...
Transient's user avatar
  • 1,362
16 votes
4 answers
5k views

Is ground connection in home electrical system really necessary?

I know that the answer to my question is "Yes, it is!". The ground connection is needed to avoid a person touching a metallic part of faulty equipment to be electrically shocked. So the ...
PauerEightySix's user avatar
52 votes
2 answers
51k views

Competing PCB Crystal layout recommendations

This is related to this question: How's my crystal oscillator layout? I'm trying to layout a 12MHz crystal for a micro controller. I've been reading through several recommendations specifically for ...
helloworld922's user avatar
39 votes
4 answers
18k views

Reason of multiple GND and VCC on an IC

What is the reason that most of ICs (e.g. MCU) has multiple (A/D)GND and (A)VCC pins? If it is to increase performance of an IC, how does it help to performance? or is it easier for the IC designer ...
Angs's user avatar
  • 3,305
13 votes
1 answer
8k views

USB 3.0 Hub shield connection

This is about the seemingly controversial shield to ground connection. The system is basically a body-worn intel-based computer, powered by a battery. Two USB 3.0 (or 3.1 Gen1) cables come out to a ...
apalopohapa's user avatar
  • 8,529
7 votes
5 answers
1k views

Professor said no current flows to ground

According to the professor, adding the ground at 0V has no effect on the current flow and current flows in this circuit as if the grounding point did not exist so the answer is E. How have people died ...
Ardalan G.'s user avatar
18 votes
4 answers
48k views

How should I connect AGND and DGND

I have been reading about grounding in a mixed signal systems. Do I get it correct that it is best to group analog and digital elements and then have a single ground plane, as long as the digital ...
Angs's user avatar
  • 3,305
11 votes
4 answers
11k views

Should there really be 1 MΩ resistance between an anti-static wrist strap and a pc?

My previous question: what exactly is grounded through motherboard standoffs? The answers suggest that a PC case is grounded in 2 ways: To the ground plane of the motherboard, through the brass ...
user avatar
19 votes
2 answers
2k views

Why does connecting a high-current device to my digital circuit cause weird behavior?

I have a arduino microcontroller other digital thing and when I connect a motor pump heater other high current thing I experience weird ADC measurements reboots crashes errors in digital ...
Phil Frost's user avatar
  • 57.7k
16 votes
3 answers
9k views

Why is there a 0R resistor linking GND and AGND in analog voltage reference circuit?

This is related to another question I've just posted (What's the purpose of a ferrite bead inductor on this circuit?), regarding the battery charger described in the AVR450 Application Note - ...
Ricardo's user avatar
  • 6,184
16 votes
2 answers
71k views

When does and when doesn't current flow to ground?

I was thinking about when current can and can't flow to ground. I came up with that current will only flow to ground when we have at least two grounds in the circuit, since then we have a complete ...
Quantum spaghettification's user avatar
12 votes
5 answers
7k views

Anti-static mat connected to earth directly or 1E6 ohm resistor?

Should an anti-static mat be connected to earth directly or with 1E6 ohm resistance in between? 2 layer mat. Upper side: dissipative (10E7 ~ 10E10 ohm/m²). Bottom: conductive. To be a little more ...
user avatar
9 votes
2 answers
30k views

Why is neutral wire connected to ground at the transformer?

I understand the use of ground wire at the home appliances but why is the neutral wire connected to ground at the transformer? Why doesn't the neutral wire go back to the power generation plants. I ...
rustyelectron's user avatar
8 votes
4 answers
2k views

How to remove noise in ADC voltage measurement?

I want to measure the open circuit voltage of a battery cell (differential reading, that is A0-A1). In order to do that, I am using an industrial PLC based in Arduino Mega and a cheap but accurate ADC ...
bardulia's user avatar
  • 407
7 votes
2 answers
2k views

USB shielding, device or host side?

I have an SBC with a USB host port, but it is exposed as male header pins rather than a female USB port. I have soldered female headers to a USB cable and have a working but intermittant connection, ...
davegravy's user avatar
  • 439
6 votes
1 answer
2k views

Sending ground along with digital connections between boards

I have been wondering for quite a while whether it's good practice when connecting two boards together (powered from the same power supply, although each has its own regulator) to send ground ...
Matt's user avatar
  • 185
61 votes
10 answers
76k views

Why is main's neutral tied to earth?

My dad is an Electrician and I myself am an Electronics Design Engineer, and to this day he still hasn't been able to give me a good reason for this. Consider the two following pictures/situations - ...
DSWG's user avatar
  • 1,620
23 votes
5 answers
72k views

How to safely ground a switching power supply with floating outputs?

I just received a 120VAC to 5VDC (20A) switching power supply (the kind with a passively ventilated metal casing) for use with a microcontroller project I'm working on (driving long LED strips). I've ...
MartyMacGyver's user avatar
16 votes
7 answers
121k views

How a person standing on a floor tile and holding a live equipment can complete the circuit?

Can someone please explain the how grounding / earthing to prevent a person from getting electrical shock using simple illustration of a faulty electric iron connected to the 240VAC mains? I don't ...
Jake's user avatar
  • 337
14 votes
4 answers
38k views

Is a ground/common needed for proper CAN bus communication?

Since CAN Bus is a differential signalling system, what is the significance of GND/COM signal? Can I get by without it? I've got a very simple 2-node system that has some weird happenings going on. (...
Adam Head's user avatar
  • 1,446
10 votes
2 answers
5k views

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 ...
Randy's user avatar
  • 3,255
4 votes
1 answer
2k views

Portable device shielding & ESD

I'm working on a portable battery-powered device with a shielded I/O connector for sensors, but I'm confused about how to properly ground the shield and ESD array. Here is a block diagram of my ...
Neil's user avatar
  • 53
2 votes
2 answers
5k views

How to add ground to DC circuit?

I'm just a dabbler in electronic circuits and I'm really still kind of a noob. I am working on a project called the "Atari Punk Console" (Originally known as the "Stepped Tone Generator") but there ...
Digital Brent's user avatar
0 votes
3 answers
10k views

Kirchhoff's Current Law at the ground node?

Can one do KCL at the ground node? Does any current go into the ground? I think not, but I am not sure. Bonus Question: If yes, then how does grounding buildings drain the current into the Earth?
user120404's user avatar
57 votes
10 answers
54k views

Why is an Ethernet cable not grounded?

There is no dedicated GND in the classical Ethernet 8P8C ("RJ45") pinout.[1] Why does the Ethernet spec not include a ground, unlike many other cable types used for interconnecting devices that may ...
mykhal's user avatar
  • 587
34 votes
5 answers
15k views

Is it a bad idea to plug the other end of ESD strap to wall ground?

I have gone through this answer on Superuser, while it provides good information, I still have a specific question from electrical/electronics engineering point of view. Is it wrong and unsafe to ...
rajeev's user avatar
  • 493
31 votes
6 answers
14k views

Noise reduction strategies in electrophysiology

When recording electrical signals from cells (in a dish or inside a living human or animal body), one major problem is to increase the signal to noise ratio. These signals are usually in the 10uV to ...
Ali's user avatar
  • 905
25 votes
4 answers
5k views

Why the arc when bonding-on during high voltage repairs?

When working on high voltage power-lines via helicopter the technician will "bond-on" with a steel wand called a hot-stick. During this process an arc is conducted from the line to the wand. Now, ...
Salbando Jones's user avatar
23 votes
4 answers
24k views

When to use ground plane cutouts?

I've been reading more about proper grounding techniques and using ground planes. From what I've read, ground planes provide a large capacitance with adjacent layers, faster heat dissipation, and ...
helloworld922's user avatar
20 votes
5 answers
12k views

RS485 network ground pin - when to connect?

As many know, one can implement a simple node to node rs485 communication by using only two wires, A and B. Well, the standard specify to connect the ground of the two node together. from Wikipedia: ...
fhlb's user avatar
  • 1,470
16 votes
3 answers
23k views

Grounding and why charge leakage occurs

A basic nugget of info is missing in my end-to-end picture of how grounding works and why it's important. When a voltage is applied in a circuit the electric current starts flowing (or the field ...
PKM's user avatar
  • 269
11 votes
1 answer
6k views

Does an ungrounded shielded cable shield at all?

Does a shielded cable provide any shielding if the shield isn't grounded? Would it be practically different than an unshielded cable?
aswine's user avatar
  • 243
10 votes
2 answers
4k views

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 ...
SomethingBetter's user avatar
9 votes
2 answers
7k views

Grounding Metal Object to Eliminate Static Electricity Using Electrical Ground

let us say that I have built a metal cabinet in which I will be painting small objects. I am looking to eliminate any static electricity that could possibly build on the object to be painted or on the ...
jmaxiom's user avatar
  • 91
6 votes
1 answer
676 views

Why do some devices have 200V on the case?

I recently got a desktop LED lamp, and I feel a "strange" slight vibration when touching the metal case. I found that other devices also have high voltage on their case. What is the reason/trade-off ...
maxy's user avatar
  • 271
5 votes
1 answer
713 views

Why does my TS101 soldering iron turn on LEDs upon contact?

An LED on my board turn on and stays on when I touch it with my soldering iron and it's freaking me out. This happens even though the board is just sitting on my (wooden) desk and not connected to ...
Almost Half Decent's user avatar
5 votes
1 answer
3k views

ungrounded chassis shielding

I'm looking into whether an ungrounded metal box provides good/bad EM shielding. This thread seems like a definite "good", for reasons of the box acting as a faraday cage : How much shielding does an ...
user2913869's user avatar
  • 1,101
5 votes
2 answers
11k views

What is signal ground

I encountered signal ground symbol while studying 555 IC Please explain why isn't a simple ground connection used and how does signal ground differ from normal ground. I am a first year undergraduate, ...
Kutsit's user avatar
  • 261
4 votes
2 answers
1k views

How does Hybrid Ground Works?

The text that is above the figure is from my textbook and i am having difficulty to understand what it is trying to say because it's not in detail!! why only remove high frequency and prevent low ...
Hilton Khadka's user avatar
2 votes
1 answer
1k views

Using aluminium enclosure as heat sink

Can I use the aluminium enclosure of my mains powered product as a heatsink? I'm thinking about mounting TO-220 transistors pressed against the enclosure, to get away with passive cooling by using ...
avl_sweden's user avatar
  • 1,024
2 votes
2 answers
3k views

Does electricity always flow in a closed loop and why does current flow to ground?

I have been taught that current flows in a closed loop back to the source. And with electrical distribution, current flows to ground because the whole grid is effectively grounded back to the source. ...
bittersweet's user avatar
2 votes
4 answers
1k views

Why earth ground connection does not leak current?

This seems like a question which has been asked multiple times on forums. I researched the problem but I still was unable to figure out the answer which I can at least intuitively understand. So in ...
Boris's user avatar
  • 177
2 votes
2 answers
1k views

Grounding a laptop through the DC-jack?

I would like to reach zero potential difference between me and my laptop (to avoid ESD) before opening the back cover. I'll connect my wrist strap to a common ground point, thru a resistorized coil ...
user avatar
1 vote
0 answers
417 views

Connect Arduino to existing circuit with seperate power supply

I have an existing closed system that exposes several inputs that I would like to drive with an Arduino. The existing system (Neptune Apex Controller with break out box) is designed to sense the ...
Harry Muscle's user avatar
1 vote
3 answers
1k views

Why do I have 44V AC between ground and the V(-) and V(+) of a switch mode power supply?

I have a system were we wish to place a USB charger outlet. The output is placed in a bench made of metal, so even if the output is isolated and low voltage, it would be a good idea to ground the ...
Dvidd's user avatar
  • 11
1 vote
2 answers
2k views

How to split Analog and Digital GND planes for a TQFN device

This question is in reference to Mixed signal PCB layout for PSoC. If I am using a microcontroller which has separate analog and digital supply inputs and GNDs, what should do with the grounds? ...
Rocketmagnet's user avatar
  • 27.5k
0 votes
2 answers
248 views

Subwoofer hums when no audio source is connected [closed]

The hum stops as soon as an audio source is connected or any metal part of the subwoofer is connected to the ground of a socket. Does anyone have any idea what the problem is?
sapes's user avatar
  • 1