Questions tagged [grounding]

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

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Connect MIDI input shield connection to ground with capacitor. What voltage / kind?

The midi specification mentions optional capacitors between connector shield and ground for a midi input: Neither the type of capacitor nor the voltage rating is specified. I would think that the ...
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1answer
46 views

What grounding should I use for this capacitively coupled input?

I'm designing a device that will receive and digitize analog video signals. In analog video, it's recommended to capacitively couple inputs. A typical input might look like this: In this case the ...
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1answer
53 views

PCB Ground Plane and Redundant Connections to Common Ground

This is a question borne of sheer ignorance, but I'm not sure if it's a good or bad thing. I'm designing a PCB (1) that will connect to another PCB (2). The latter has all of the power, ground, IO ...
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1answer
26 views

Common ground b/w power supplies and analog pin for microcontroller

Referring to the schematic below, is it best practice to have the 5 V supply on the right powering the MC (arduino-esque microcontroller) share a common ground with the 24 V supply ? The 24 V supply ...
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1answer
57 views

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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1answer
29 views

Grounding GPIO pins during 8051 programming

I'm trying to make a programmer for the 8051 microcontroller IC's, specifically the AT89C2051. I saw a circuit online (the blowit programmer) in which the unused GPIO pins are left floating. When the ...
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1answer
76 views

Difference in current transformers conection for ground fault detection

I have seen that for detecting ground faults on a 3-phase system powered by a secondary wye connected transformer, current transformers (CTs) can be connected in several ways: On the ground ...
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1answer
42 views

Should I tie my various DC power supply 0 V rails to ground?

I'm putting together the controls for a CNC router table I'm building. In the enclosure I've got some DIN rail power supplies, contactors, and terminal blocks. Also in the enclosure is the VFD for ...
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5answers
578 views

How can I get ground from a NEMA 5-15R wall socket without electricity?

I have some network equipment that I want to connect to ground (they come with 2-prong wall wart PSUs and have a separate screw hole for a grounding pigtail) - but where would I get ground from in a ...
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0answers
31 views

Electric Shock in Walls and Electrical Equipment [migrated]

I'm getting a shock when I touch walls, electrical equipment like a water cooler, fridge, etc in my home. I have followed this procedure as I only have a DMM with me. The readings I got after ...
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8answers
5k views

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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0answers
18 views

Grounded outlet with load for ungrounded outlet [migrated]

Moved into a place, nearly every outlet is ungrounded with the exception of a couple GFCI in the kitchen and bath. Needed three prong for the fridge (and really didn't want the new appliance ...
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3answers
86 views

Large Power System - Separate Earth Grounds?

I'm a EE working on a scientific instrument that is large in scale, like a building. The structure is all metal and will have many server cabinets and electronics equipment, motors, sensors spread all ...
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2answers
43 views

Grounding balanced secondary isolation transformer for EMI suppression

simulate this circuit – Schematic created using CircuitLab Which is the best secondary connection to clean the main line power from EMI, line noise and HF harmonics by using an isolation 1:1 ...
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1answer
96 views

How should I connect the audio ground and shield wires in a Cat5 cable for analog audio?

I would like to carry 3x balanced line level (not mic level) signals to another part of my living room and I found that the cable space in the skirting boards would not allow 3x balanced cables (XLR ...
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0answers
38 views

Unexplained differences in behaviour between U.FL-terminated antenna and SMA-terminated antenna

I would like your opinions/advice regarding an unexplained observation between a U.FL-terminated antenna and an SMA-terminated antenna. Both antennas are from the same manufacturer and normally tuned ...
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1answer
72 views

Can somebody please explain to me the principle of a T-T Earthing system?

How are the transformer, consumer's side and the generator earthed in a T-T Earthing system? I seem to understand that the generator and its frame should be earthed separately; The neutral of the ...
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1answer
36 views

Grounding and shielding between isolated devices

I have a battery operated micro controller with a hall sensor, mounted on a motorbike. The hall sensor has a shielded cable to counteract spark plug induced EMI. By default, the entire setup is ...
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2answers
119 views

How does grounding prevent electric shock?

I understand that an electrical appliance will be connected to ground to provide a path back if there is a fault and a live wire touches the case. However if a person is also touching the case at ...
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3answers
71 views

Line to ground faults

I am having a trouble understanding the concept of line to ground faults,and ground in general. In this simple single phase circuit, does current reach the load and the circuit operates normally? ...
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0answers
42 views

Why is there a positive body voltage when grounded, but none when not?

So after reading about earthing and earthing mats, I decided to make myself a very basic one for cheap to test the concept before jumping in with purchasing more sophisticated products. Here's what I ...
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1answer
81 views

why is it bad if a coax cable (used for antenna cable) has multiple paths to ground?

I have an Internet modem/router device connected to a 20 foot LMR400 coaxial cable which uses N-to-N type connectors to connect to a 10 foot LMR400 cable, which is then connected into an ...
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2answers
57 views

Earth line safety [closed]

I am working with a conductive appliance that a user will be in constant contact with over extended periods of time and the appliance is constantly earthed. These two facts cannot change, other than ...
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1answer
24 views

Do the dipole antenna edges have earth potential or is it a closed circuit made of co-axial cable?

I understand the shape of the dipole antenna, but how is it fed so that the current only flows through one direction during the half cycle? Even in a normal pole antenna, is there a ground at the edge ...
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1answer
36 views

Is it right to define ground as a pool of surplus free electrons, like a metal?

In a dipole antenna or any other pole like antenna, there is supposedly a ground on one side causing the current to flow away and towards the ground towards the feed, but if the whole antenna itself ...
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2answers
136 views

Connect IR Emitter (+) to IR Receiver (+)?

I have a vehicle stereo deck that has an IR receiver input (+) and a steering wheel control module that has an IR emitter LED (+/-). The steering wheel control module, "translates" (using a mapping ...
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1answer
125 views

Grounding PCB Within Aluminum Enclosure

I have been doing some research on this question and, while I found a number of questions here asking something similar, I don't quite get the side-by-side comparison I am looking for. Therefore I ...
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1answer
49 views

LCD suddenly stops displaying

I am using a PC2002LRU-BWB-H-Q LCD with a STM32F4 micro and is powered through a TMP10424. There is also some 3V3 and 5V modules to. The problem is that the LCD is displayed fine for over days and ...
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0answers
62 views

Does regularly spaced via stitching contribute to standing waves on an RF PCB?

Should vias be irregularly spaced? Can consistent spacing between ground vias create standing waves. Has anyone ever heard of this? I've been doing this for awhile and I've never heard this and ...
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1answer
55 views

Motor / VFD / Protective Earth

I have little experience with AC motors since I'm majoring in Mech.E. My team is setting up an AC motor with a VFD to control the movement of an airfoil inside a metal cage we built. I understand the ...
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0answers
33 views

Protecting Copper Anode in 12V DC System

Getting to grips with cathodic protection here. If someone had a 12, 24 or 48VDC system, say solar PV and batteries, and the battery negative is earthed, this means the earth is the cathode, and the ...
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1answer
142 views

PCB ground connection for shared power/data bus system

I have a wireless device that is connected to a shared power and data bus, similar to below. The bus can be shared by up to 5 devices and I don't know what it will be connected in advance. I connect ...
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3answers
28 views

Connecting the Block AIM 5.0/2.0 auto-transformer to UK three-wire plug

I am not electrically very knowledgeable person. At the moment I am trying to connect a Block AIM 5.0/2.5 Auto-transformer to a piece of very sensitive medical equipment. The auto-transformer was ...
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0answers
29 views

How to have Wye-connected Potential Transformers(PTs) and Neutral Ground Resistor short circuit detection at my ground fault protection relay?

Detecting if the Neutral Ground Resistor (NGR) is shorted is something that must be checked at the Ground Fault Protecting Relay. The typical way to do this is to inject a DC component and to measure ...
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1answer
46 views

Correct way to ground components for solar panel measurement

I'm currently doing a project where I'm supposed to measure the current and the voltage from a solar panel and am unsure of how I should ground all the components in the circuit (since electrical ...
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1answer
75 views

How do I connect an LED with floating DC voltage?

I want to connected an LED at the output of 500V DC. This DC power supply is made by 3phase DC rectifier and is floating. I would like to have a display on the front panel of the supply which will ...
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1answer
44 views

Ground anti-static bracelet without ground wire

I recently damaged a IC with my own static while soldering it. So I decided to buy a anti-static bracelet, but.. here where I live (Brazil) almost no building has proper grounding, only neutral and ...
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2answers
116 views

Grounding of IT equipment for office ESD protection

We've been having a lot of problems in my office with ESD. People touch cubicle frames and monitors shut off momentarily, painful shocks through laptops, etc. I'm worried about equipment getting ...
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5answers
6k 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 ...
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3answers
45 views

Mitigating touch current in two-pronged AC without dedicated ground

I'm trying to work on a simple circuit where (simplified) I plug in a 240V 50Hz AC through a resistive coil to convert to heat. The coil is insulated and placed under a metal plate. I'm noticing that ...
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4answers
2k views

How does residential electricity work?

I'm trying to understand how the electricity works in my house. I live in the US. I know that at the transformer, the primary winding induces a current in the secondary winding. The secondary ...
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1answer
58 views

Where does current go after flowing to earth?

I know similar question have been asked several times, but I didn't get exactly the answer I was looking for. I actually want to ask something that perhaps can worded as a practical question, but I ...
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1answer
66 views

Shield ground to metal body or signal ground?

I have a question about grounding. I will have two short shielded cables with signal wires inside, located at the top of a tower. The cables have a grounding wire inside shorted to their foil shields ...
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2answers
489 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, ...
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3answers
88 views

If two objects are grounded, why do they still need to be bonded? And if they are bonded, why does each still need to be grounded? (fire safety)

When transferring a flammable liquid, both the container and the receptacle are supposed to be grounded and bonded. If they are both grounded, shouldn't the change on each be equal to ground? And if ...
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1answer
104 views

Adding SMA conectors to a device whose metal casing is connected to earth ground through at a single point

We are iterating a device whose metal chassis is internally connected to an ESD guard ring that is connected to the PCB signal ground through a 0Ohm resistor in a single point close to the power ...
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2answers
163 views

Is it a good idea to ground a heat sink?

Have a nice piece of Motorola obtainium that I want to use to power a Raspberry Pi, and I also happen to have a left over ground wire (the case has a three-lead power connector). The case is 100% ...
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1answer
108 views

Earthing system on a mobile vehicle?

We have an electrical system which needs a low impedance earthing system below two ohms. We have provided a proper earthing system in our factory and it works well. Now my question is if the system is ...
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2answers
3k views

Why is there a voltage between the mains ground and my radiator?

I have an anti-static mat that comes with a plug that only has a ground lead. Out of curiosity, I measured the voltages between the live, neutral, ground, and my radiator. As expected, there is ...
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0answers
22 views

Extension cord from grid through GFCI outlet to off grid inverter. Does the extension cord ground need connected?

I have an off grid system: PV, charge controllers, inverters, and batteries. I want to add a 120V grid input from a GFCI outlet through an extension cord directly into the inverter AC input. However, ...