Tagged Questions

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

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0
votes
2answers
57 views

Earth connection missing on electric circuit, getting lots of noise with audio equipment

I have a question today that possibly crosses to another website, but i'm interested in your expertise here. It's more or less about music, but also about noise and electric current. Basically, I ...
1
vote
1answer
39 views

pH sensor project: trouble with RF interference

I built this pH sensor project on a breadboard and I'm having a big problem. The output on the voltmeter is completely erratic, and I'm pretty sure it's due to RF interference. When I connect the ...
8
votes
1answer
564 views

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 ...
0
votes
0answers
34 views

Dilemma when ground and earthing is used [duplicate]

What are the differences in ground, neutral and earth. I came to a point neutral grounding. Is it differ from earthing? And any difference in representation of all.
9
votes
2answers
590 views

Why are some mounting holes connected to ground?

Why are plated mounting holes connected to ground ? I read that if you are connecting your board to chassis ground, then it should be connected at only one point and connecting say 4 mounting holes ...
2
votes
1answer
71 views

Grounding for car stereo adapter PCB

I've built an audio adapter for car stereo system. It contains microcontroller, a connector to stereo system (a few data pins and line-level audio output), Bluetooth audio module (RN52) and power ...
0
votes
1answer
54 views

Shielding not connected to USB connector causes tablet restarts

I have a custom USB cable, USB type A male on one end and a DB-9 connector on the other end (only using 4 pins). The shielding of the cable is connected to the USB connector but not the DB-9 ...
0
votes
1answer
53 views

Hooking audio compressor to mains without chasis

I am nearing the completion of my DIY compressor project, and I have a rather seemingly basic question.. Once I hook up my toroid and everything, since I don't have my 19" 1U rack enclosure yet, but ...
0
votes
0answers
28 views

high voltage chassis grounding [duplicate]

Suppose a high-voltage transformer has its chassis grounded, is it safe to touch the chassis? What if the HV terminal accidentally touched the chassis at point A @ 10kV, while the grounding is at ...
1
vote
1answer
84 views

high voltage safety [closed]

I remember having seen microwave ovens without the earth connection. My first question is : Is it correct that if you touch the MOT transformer chassis, but leave the other terminal floating in air ...
3
votes
1answer
87 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 ...
0
votes
0answers
30 views

Needed help on earthing grid mat installation

I needed knowledge about earth mat installation for underground metro. I am not sure if a test reference electrode could be used for two earth mats. We have limited space and I want to cut off some ...
8
votes
3answers
824 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 a analog voltage reference circuit?), regarding the battery charger described in the AVR450 ...
2
votes
2answers
729 views

PCB design review: Decoupling, bypassing and grounding

I'm trying to make my own wireless sensor using ATmega microcontroller. I've some basic understanding of electronics but I'm a total amateur when it comes to designing circuits and PCBs. This is just ...
0
votes
1answer
52 views

Voltages with an earth ground

In this diagram, from what I understand the voltage between the positive terminal and the first earth ground is \$ 0V \$ and the voltage between the negative terminal and the earth ground is \$ 0V ...
1
vote
1answer
70 views

Compromise needed combining virtual grounds

This is a long story for which I hope my proposed solution to a problem I've created will be a stable one. But op amps can surprise you, so let me explain. The circuit is large and complex, so I'd ...
1
vote
3answers
329 views

Child-Safe setup for ESD protection environment on desk

I need to setup an anti-static workbench in my spare office, and kids sometimes get into it ever since they learned how to pick the locks. My intended approach is to: Lay out an ESD mat on the ...
1
vote
1answer
66 views

From grounding to audio amplifiers

Ultimately I would like to assemble this simple audio amplifier: Given my lack of any significant knowledge in the topic I have several problems and questions. Grounding: In the thread What is ...
1
vote
3answers
85 views

Will standing on a non-conductive surface with wet feet prevent grounding and therefore electrocution?

It is a well known fact that one should not handle electrical equipment in general and electrical home appliances in particular when barefoot, or when one's feet are wet (even when wearing ...
0
votes
2answers
83 views

Grounding in buildings

I'm not sure if I understand the concept of grounding correctly. Suppose I live in an apartment's 10th floor. Now the main panel is installed in the 1st floor of the building, and I want to setup a ...
0
votes
1answer
65 views

Repairing (possible) earthing/ground issue in computer PSU? [closed]

I've got a computer that will no longer power on. It used to be willing to power on quite randomly, and ran fine when it did. I'm not an electronics savvy person, but i've done a manual check on the ...
6
votes
4answers
537 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 ...
11
votes
4answers
926 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 ...
4
votes
1answer
76 views

How to reduce objects/hands impact on PCB antenna efficiency

I am trying to learn about planar inverted F antennas creation and have designed two different designs for two different frequencies with success. One seems pretty much unaffected by the proximity of ...
1
vote
2answers
78 views

Can I use a double insulated power supply with a metal framed sculpture with LEDs

I have built a tree shaped wire framed sculpture with LED lighting. The LEDs each have a positive supply to the anode via an insulated wire and resistor, and the cathodes are connected directly to the ...
1
vote
1answer
56 views

Routing Audio Ground - needed or not?

I'm trying to build a guitar pedal switcher (efectively a box that provides multiple effect loops that can be independently bypassed from a single microprocessor) and while building a working ...
0
votes
1answer
34 views

Is it advisable to try to discover a place to make a ground connection on a board with a separate AC power supply?

I am building a device consisting of a microcontroller (an Arduino mini) attached to various output devices, which will be triggered using a wireless doorbell receiver. The receiver is a single board ...
0
votes
0answers
21 views

How to rectify the power line for leakage current based electrical shocks? [duplicate]

In May 2014, I had purchased Samsung LCD TV with two pin mains cord. I used to get electric shock like feeling when I touched the metal body part of it or the HDMI port (any other connected ungrounded ...
2
votes
0answers
57 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 ...
0
votes
0answers
69 views

Does the following power supply configuration make my device a safe and legal PELV appliance?

A small disclaimer up front: I am fully aware that advice from this site is not a replacement for a safety evaluation by an expert. I merely want to check my understanding of the rules and potential ...
1
vote
1answer
252 views

Grounding the chassis with capacitor

My question involves chassis grounding to earth ground. My PCB circuit is a simple signal generator using a microcontroller. It has a separate 'ground' from earth ground, supplied by a floating 5VDC ...
3
votes
2answers
286 views

Why the neutral of the UPS or inverter or generator is advised to be earthed/grounded?

In my company we had few earthing related issues. When an consultant was brought in and apart from solving the issue, a suggestion was made to ground the neutral of the UPS and diesel generators that ...
4
votes
4answers
291 views

Properly grounding 2 MCUs using I2C

I'm building a mechatronic system that consists of 1)XY Gantry controlled with PIC32 and a DIY motor shield and 2)control box with PIC24 three potentiometers + room for expansion, typically located ...
0
votes
0answers
95 views

grounding 2 different power supplies

I have 2 circuit boards I'm trying to connect together that each have a common 24 VAC source they are connected to. The problem I have is I'm trying to feed a switching 12 VDC signal to the one board ...
3
votes
1answer
106 views

Ground and power PCB layout for MCU

As you know most of the MCU's has several Vdd and Vss pins. In the case of two-layer PCB it seems convenient to use some polygons beneath MCU (like on the figure below). The first option is treat the ...
1
vote
1answer
61 views

SCR triggering and ground loop issues

I am trying to trigger an scr/thyristor from a 0-5V TTL pulse (channel 1 on the oscilloscope output). The schematic can be viewed below. I am using the TTL to pull the 2n2222 transistor 'on' which ...
3
votes
2answers
295 views

Grounding unused leg of bussed resistor?

I've got a bussed resistor: The package I'm using has 13 inputs and 1 output, tied to ground. I'm only using 11 of the inputs. Do I need to worry about the floating end of the two unused inputs? ...
1
vote
2answers
136 views

Variable Voltage Using PWM and Low Pass Filter

I am trying to control a steady DC output voltage using a Micro controller with a PWM duty cycle. With the current schematic, the Voltage on Vout is pulsing along ...
1
vote
1answer
74 views

Arduino Ground reference plane

There are three GND pins on the Arduino UNO pinout. As I'm trying to design a mixed signal PCB to act as an Arduino Shield, I wonder how I should connect those pins, i.e. to the analog or digital ...
0
votes
1answer
55 views

Why a ground loop a problem, not a ground plane(patch attena)?

The question is as the title says: I see various material saying using a solid ground plane. Why would not that be a problem, since a solid ground plane could be a patch antenna?
1
vote
3answers
267 views

Two Five-foot Ground Rods vs. One Ten-foot Ground Rod

I am thinking about installing two five-foot ground rods in place of one ten-foot ground rod. What would be the relevant comparison(s) and contrast(s)? Let me know if you need further information. ...
1
vote
1answer
107 views

Can I connect all ground connectors via the ground fill?

I am working on a very, very simple two-sided PCB design that connects one 8-pin header with 6 audio jacks, each of which has its right channel and ground connected. All grounds are connected via ...
0
votes
1answer
70 views

Question on capacitive circuit in practice

If we were to build a circuit, let's say with a power source of 120V AC going into a transformer which steps that up to 10kV @ 30mA, the output of which would be connected to a capacitor with a ...
1
vote
3answers
135 views

How to deal with grounding and the capacitors in this opamp schematic?

Here is a schematic I'm planning to make (right click on the image and 'open image in new tab' to see it better'): I have a transformer and AC to DC converter that makes +/-12V. (1) Does 'power ...
0
votes
1answer
95 views

How to implement grounding into this electrical circuit?

I'm trying to make some tutorials but I have no idea what should I do when I see the term ground (GND). Here is an example: I want to know how I build the GND part. Where I connect it? Also, if ...
0
votes
1answer
139 views

Laptop surface vibrating when rubbing over it [closed]

Because my previous HP laptop adapter stopped working, I got a new one. But if I use this one, I feel a kind of vibration when I rub over my laptop's surface. I don't have this if I work on battery, ...
0
votes
0answers
99 views

Connecting grounds of following circuit

simulate this circuit – Schematic created using CircuitLab I am using 5V supply derived from rectification of 230V AC and using 7805 IC for DSP while I am using 0-300 V DC lab bench type ...
0
votes
2answers
144 views

Binding LM4871 audio amp output to another circuitry with ground referenced input

I using LM4871 as a audio pre-amp in my device. If I let the output to earphones or external speakers then it works great. If I want to loop LM4871 output (pin 5 and 8) back to one of the local audio ...
1
vote
1answer
46 views

MCP41100 Power supply and grounding ? Analog ? Digital?

I'm thinking of using an mcp41100 digital potentiometer to control an op amp gain. My board will have a split ground plane - digital and analog grounds. Unfortunately the mcp41100 doesn't have ...
3
votes
3answers
90 views

Grounding a Device And/Or Room

Hoping this is the correct exchange. At the moment I'm currently renting my house in Canada (120V), and it seems the landlord has attempted to try pull a fast one. From what I understand, or possibly ...