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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45 views

Stray voltage on ATX MB ground [on hold]

I have recently observed a strange thing. On my server (repurposed desktop motherboard + PSU + 2xHDD), as I was wiring it, I touched one of the connector casings. You know the ones on back, of which ...
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64 views

RFID reader sensitivity/read range - How does a “hard” ground increase sensitivity/read range?

I'm working with two RFID readers in my circuit and an arduino to control both of them. The whole thing is powered by a very cheap wall-wart Power supply at 12V which is rather noisy to begin with. ...
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1answer
83 views

What to do with ground wire?

I have a few I/p transducers(which work on 4-20mA loop current) and I have made a single cable for all of them, they each have posititive, negative and Ground wires. The controller I have for these I/...
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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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1answer
52 views

Do all common grounds end up to the chassis ground?

I'm new to electronics, and still wrapping my head around "common" and "ground." The schematic is: My question is if ALL the solid black grounds/commons end up at the one going to the cap/resister ...
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55 views

fault current through a person

Say a person touches the live wire as shown in the first attachment, the current will flow through him and dissipates into the ground as shown in the second attachment right? the fault current through ...
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59 views

Grounding considering signal return path

I wanted to ask if there is a difference between 2 scenarios on the illustration i've included. If we have 2 or more boards interfacing with each other should we connect every output with it's own ...
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2answers
67 views

Is a ground plane meaningful even where the signal return path is not through ground?

I'm designing a two layer PCB for a keyboard where most of the board space is taken up by the key switches and backlight LEDs. The switches have a traditional switch matrix configuration with diodes ...
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2answers
76 views

Why there is a grounding on device with two prong cord?

I am curious why there is the grounding on a device with two prong cord? As far as I know there should be 3 prong cord to make the grounding working.
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1answer
78 views

Why are overhead electric wires allowed to have higher voltages than third rails for rapid transit railways?

I hope this question is on-topic for this site. The city I live in (Chennai, in India) got a rapid transit metro rail a few years ago that uses overhead electrification of 25kV, 50Hz AC voltage to ...
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2answers
69 views

Why do stoves need not be connected under the earth leakage?

On some stoves I've seen stickers stating that the stove doesn't need to be connected under the earth leakage... Which is rather confusing since we need to earth it in case of earth faults. I'm just ...
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2answers
54 views

Earth continuity of slot together aluminium enclosure

If I were to use a slot together aluminum enclosure for a mains powered device, and I earthed one panel of the enclosure by fitting a stud, how could I ensure continuity of the earth to the whole ...
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1answer
73 views

Will leaving 1 of the 3 GND pins on the ATMEGA328p ungrounded cause any problems?

I am creating a circuit using an ATMEGA328P and i am unable to ground one of the 3 ground pins (other 2 are fine) due to limitations of my design. I have tested the IC with a multimeter and the pin ...
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1answer
63 views

Should isolated GND be tied to logic GND to prevent ground drift?

In an industrial environment, let's say you have an isolated interface that connects to an external sensor or device. This interface separates both logic signals to your main board as well as GND and ...
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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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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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5answers
94 views

Open circuit ground multiplexing?

I am experimenting with electrospray ionization. The setup has a 4kV power supply connected to an electrode that is separated from a return lug (or ground plate) via an air gap, followed by an inline ...
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2answers
41 views

Pulsed DC current measurement using arduino and shunt resistor

I am currently working on a project ( to develop a constant current pulsed DC supply) in which current has to be measured using Arduino's analog input (Upto 20A) passing through a variable resistance ...
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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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41 views

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
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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1answer
61 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
27 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
62 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
31 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
117 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
48 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
589 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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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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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
48 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
101 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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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
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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1answer
37 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
133 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
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
51 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
84 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
59 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
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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1answer
38 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
138 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
153 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
68 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
73 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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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
157 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
32 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 ...