Questions tagged [grounding]

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

76 questions with no upvoted or accepted answers
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89 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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0answers
1k views

Why is the line-to-ground voltage half of what it should be?

Our electric power provider delivers 240 V, 60 Hz split-phase power to residential buildings. I've been checking our three-prong receptacles and I normally get the following measurements: line-to-...
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0answers
211 views

Flyback Transformer - Grounding the Ferrite Core

Today I dismantled (I hope this is the correct verb) a flyback transformer. The thing that I've never seen is that one end of one of the windings is "glued" to the ferrite core (Before you ask; yes, ...
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0answers
400 views

Why did this arduino burn out? SilentStepStick (TMC2130) stepper at 24V

I'm new to electronics. Attempting to bench-test a SilentStepStick stepper driver board, (based on a TMC2130) Using: Arduino Uno, a SilentStepStick driver board, a 0.6A stepper motor, and waterott ...
2
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0answers
750 views

Conductive or insulated motherboard-standoffs?

AFAIK it's common practice to mount an ATX motherboard to conductive brass standoffs inside the case. There are even metal traces around the screw holes to provide contact between the screws and the ...
2
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0answers
208 views

PCB layouts and polygon pours

I have been told that when laying out a PCB to keep all the polygon pours uniform on each layer. So, for example, in a corner of the PCB, you do not want the pour on one layer slightly offset relative ...
2
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0answers
2k views

How to calculate the earth fault current in a transmission system with no ground wire?

Background information, and my thought on the matter are provided in the end of the question. I need to calculate the fault current in case a fault occur for instance 10 km away from a transformer ...
2
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0answers
340 views

Grounding with a battery-powered differential amplifier

I have made a simple battery powered instrumentation amplifier (based on the AD8429 chip) for some very low noise measurements. The rough circuit diagram is below. Note that the BNC input is isolated ...
2
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1answer
448 views

Advice for Grounding and Shield Placement

I am working on a board design which includes an ADC and a DAC. The board attaches to the headers of the Mojo V3 Spartan 6 FPGA Dev Board. The ADC has to pick up a quiet signal at the same time as the ...
1
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1answer
48 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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2answers
49 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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0answers
69 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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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 ...
1
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1answer
78 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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0answers
31 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, ...
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77 views

Connecting the secondary side of ignition coil to earth

I have an ignition system used for some application. During the testing I found that spark plug is producing EMI due to spark occurrence and high voltage is traveling through the wire. So to ...
1
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1answer
57 views

What is the relationship between Ground Potential Rise (GPR) and Source Voltage?

I am looking at the results for an earth grid study for a 50Hz substation. Primary Voltage (Vp) = 11,000V Secondary Voltage (Vs) = 415V Secondary Fault Current (If)= 24kA Secondary Grid Current (...
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44 views

Preventing the voltage between two isolated grounds from exceeding max rating

Consider the low-side current sensing application shown in Figure 1. Grounds 1 and 2 are galvanically isolated. Assume, for example, ground 1 is the NEUTRAL line on mains power (\$V_g\$), and ground 2 ...
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1answer
66 views

Substation grounding

I am trying to understand a grounding system for substations, fault current is something I am not getting. For example, for a small substation with some transformers, if there is a fault in the system ...
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2answers
143 views

Separate grounding for analog and digital portions of circuitry

A datasheet suggests separate grounding for analog and digital portions of circuitry (http://www.ti.com/lit/ds/symlink/am26c32.pdf#page=12). Is this to say that the IC's outputs should have a ...
1
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1answer
257 views

SiPM Array, High Speed Layout

I'm working on an prototype array of Silicon Photomultipliers using the Sensl MicroFJ-60035 TSV device. It's a small 6 mm by 6 mm square-shaped BGA photomultiplier. Think of a 6x6 BGA array with the ...
1
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1answer
56 views

About ideal floated measurement

In the book "Grounds for Grounding", p. 573, it give a figure: And it states: In a perfectly balanced circuit (i.e., \$Z_{H} = Z_{L}\$ and \$Z_{HG} > = Z_{LG}\$), where \$Z_{HG}\$, and \$Z_{LG}\...
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113 views

Static and Dynamic Ground Difference in Daisy-Chain powering scheme

I am using a +24 V distribution bus to transmit power to 10 loads spread over a meter (e.g. each one at 0.1 m distance). The power distributed daisy-chain style using 2x10 flat cables (computer cable) ...
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406 views

Devices USB grounding

I just opened a PC a client brought, with some software problems. While fixing those problems I opened the case to check if there was something that needed maintenance and I noticed the USB shield ...
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0answers
54 views

Where to ground my system

Recently, I made a small measurement system with three boards. Below is the block diagram: The power ground cord is connected to the chassis at power entry. I think I need to connect the GND to ...
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0answers
166 views

DIN Rail with In-Rail Bus - GND/PE design question

We are designing a system that consists of several modules that are mounted on a DIN rail. They are connected to each other using an In-Rail Bus system like this: System design: The 5 bus line ...
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0answers
226 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 ...
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0answers
163 views

Safety/Quality issues by modding PC PSU to be floating.

Since I don't have enough money at the moment to purchase a good bench power supply, I want to 'mod' a PSU. In the first instance not by opening the PSU, but just by making an adapter that also puts a ...
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33 views

Differential input pH schematic reading

I am trying to understand the following schematic for a differential input pH probe. here is the link A1 and A2 role are unity gain opamp amplifying high impedance probe signal, while A3 makes the ...
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2answers
50 views

How to connect the GND with the metal case of the robot

I have a PCB design inside a metal case of the robot. The robot is mobile, it moves on wheels. The problem is how to connect the GND with the metal case of the robot. Direct connection is not safe, ...
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0answers
23 views

How to ground a codec (TLV320AIC3105)

I'm trying to design a board with an audio codec. All signal connections seem to be pretty straightforward, but I have a major trouble with ground. I belive there are at least 3 contradicting ...
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42 views

between earth and ground

In my 100 Watt ACI Drive circuit, I've confusion about which components will be best to connect between DC_Bus Ground & Earth? FYI: 300 VDC for Motor & 15 VDC for Logics & other ...
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0answers
40 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
39 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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3answers
76 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
52 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
25 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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0answers
38 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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0answers
47 views

Bootleg grounds on residential 2 wire 110v electric circuits

I bought a old duplex house with 2 wire electric circuits and 3 prong outlets. A home inspection found the outlets had no ground,the seller agreed to having an electrician "rectify" this condition ...
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1answer
48 views

how to make different grounding

yesterday when i ask about driving circuit, someone told me that it is a little use in optocoupler when i use the same ground everywhere. because so far (iam a green hand in electronic) i just connect ...
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0answers
74 views

Grounding the components of a DIY cnc machine

I'm in the process of building a DIY cnc machine. It already runs, but I noticed it has some interference problems (steppers act weird on occasions, the full graphic smart controller LCD has trouble ...
0
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1answer
54 views

Can leakage current to ground generate static electricity?

I'm having a weird issue at my workplace where some industrial equipment is present. Almost every time I leave my laptop (with grounded aluminum body) for a while and come back I will get a quite ...
0
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1answer
55 views

Device's ground riding on a non-ground signal

The question is somewhat conceptual, feel free to close if it's too off-topic. If I take my portable (battery-powered) oscilloscope and try to measure the mains voltage, the connection polarity ...
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1answer
40 views

Digital signal integrity & grounding

I have a battery operated device with an old B&W LCD in it. I'm tapping to the display bus and would like to input it into an FPGA for some processing. The bus includes vertical and horizontal ...
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0answers
42 views

Odd Ground/Power(?) issue with Mixing Desk - alternate grounding?

I am a bit stumped with this one. Unfortunately there are a few variables involved, but I will do my best to ask an answerable question.... I just built a DIY synthesizer. It functions absolutely ...
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0answers
105 views

How to line a Metal Melter secondary for higher safety

A Metal Melter is a kind of home-made low voltage (less than 40 volts, mine is 3v) welder (small-scale) made from a microwave oven transformer (MOT). I left the primary intact (the thicker wire, which ...
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0answers
137 views

Earthing for Satellite Dish

A friend who is an electrical engineer (heavy current) told me to earth my satellite dish and its fixing pole against lightning, using a thick copper cable (6 sq.mm) and an earth spike. He also said ...
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0answers
96 views

PCB Grounding Plane Review

I am reviewing a 6 layer board that has analog signals on the left and right side of the board. I have always read that analog circuitry should be grouped together for easy plane segmentation. ...
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1answer
132 views

Crossing ground planes with low current low frequency signals

I have a board which has two ground planes, analog and digital, that on this board are completely separate. The grounds connect on another board, which is connected via a flat cable. All signals on ...
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1answer
23 views

MAX31865 RTD converter will it acccept only floating inputs?

We intend to use MAX31865 for measuring resistance values. Since MAX31865 is RTD to digital converter, kindly clarify whether the MAX31865 will accept only floating inputs or it can be used with ...