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

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2answers
43 views

How do I connect the virtual ground as shown below

This is a circuit for EEG. How do I make the connections labelled as Virtual Ground? Also, how do I connect the 1M trim pot in the top right?
0
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1answer
67 views

Are Faston tabs safe for earth grounding?

I am having a discussion with coworkers about sufficient grounding to a chassis... my opinion is that a toothed ring terminal in contact with bare metal is required, e.g. Molex 19074-0025, so that the ...
-1
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1answer
48 views

Ground isolation

I am looking at ways to isolate my board and supply ground. I am feeding my board with a 40V dc power source. Now, the ground return of my board should not be connected to the battery return is the ...
1
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1answer
23 views

about grounding on different circuit board

I got a STM32 development board, which is used to control another board for DDS output. The STM32 board send digital signal (TTL) for output control on the DDS chips. The STM32 board and the DDS board ...
5
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4answers
715 views

How do I decouple ground planes?

I have designed and built a motor controller circuit. The circuit has a microcontroller on which gets commands from a PC using an FT232R. Currently the FT232R is powered from the board's +5V supply. ...
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1answer
45 views

grounding measurement methods

As long as I know the accepted methods for measuring the resistivity of electric grounding grids, once they are built, for any kind of building (in cities, at industrial level, transmission towers, ...
0
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0answers
51 views

FDNR instability

Can anybody advise me, I have made many attempts to make a practical FDNR circuit, but it is always very unstable with lots of RF oscillation. I am trying to make and audio filter, that is the ...
0
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0answers
65 views

Peripheral Board Power Issue

after having designed some custom PCBs, a main one with an ARM MCU and other peripheral boards.But there is one issue when peripheral boards are plugged into the main one. Please, let me introduce ...
3
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2answers
93 views

The back of a pot used as a signal ground, in a grounded chassis design; how reliable?

This question relates to those large pots with solder terminals that are still used in electric guitars; they used to be common in metal-chassis radios, amps, TV, as volume and tone controls. It was ...
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1answer
58 views

Is it always OK to directly connect grounds of different voltage sources?

In my specific case, I have an arduino and a servo motor. Arduino is powered from PC via USB (5V). Servo is powered from a separate AC-DC adapter because it needs more current. In order to control ...
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2answers
44 views

Static Discharge on Metal Enclosure for Tablet causes restarts

The setup I currently have is a Aluminum enclosure for an Android Tablet. Inside the enclosure, a shielded USB cable is routed into the micro USB port and out through a small opening. This cable is ...
20
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5answers
4k 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 thing they are the same. Can I use the neutral wire for protection purpose and connect ...
0
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2answers
53 views

Connecting Vcc pin to a logic gate

I have a sonar sensor which has 4 pins and may be due to a bug in my code, they are freezing in a few seconds after functioning. I found out if I reconnect the Vcc pin, they start working and yeah ...
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2answers
117 views

Arduino: How to read sensor without common ground?

I want to analogRead() the voltage coming from a plasma cutter and serial print it. The problem is that the serial communication between my laptop and Arduino are breaking as soon as i turn on ...
1
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2answers
149 views

How to wire 3 phase motor to VFD

I am trying to wire a new motor to a variable frequency drive (VFD) and having some trouble figuring out how to wire the motor to the VFD. The motor is a 1 HP, 3-phase, 208-230/460 volts, and I'm ...
0
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0answers
32 views

How to check the grounding of rack shelf for ESD

Can anyone suggest how to check the grounding of the Metal Rack Shelf for Discharging Static Electricity? I have an Earth tester with three terminals. Is it possible to conduct the test by using ...
1
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1answer
68 views

PCB plane cuts for audio paths in mixed-signal device

I am working with the TLV320AIC3204 32-bit audio codec. The codec has three inputs and two outputs. While I was designing my own test PCB, I noticed on TI's evaluation board (on page 33) that they ...
0
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1answer
38 views

How to place decoupling Capacitors in a star ground design?

I am in the process of routing a star-grounded amplifier pcb and wondered on how to connect the decoupling capacitors. As I see it I have two choices: Connect the ground of the capacitors directly ...
0
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2answers
53 views

Connecting Analog GND and Digital GND of ADC

I'm trying to make a simple line tracing robot, however I couldn't figure out how to connect AGND and DGND of A/D converter(MCP3208) on a simple perfboard design. I need some guidance how to smooth ...
2
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1answer
115 views

How can one use the earth as a second wire?

I read recently that the earth can be used as a wire to save wiring costs. My understanding of how this works is that a power source, say a battery, separates charge, creating electrons on one side ...
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2answers
55 views

Mounting Hole Connected to Ground Through Capacitor

I've inherited several board designs where each of the four [plated through] mounting holes are connected to the board's ground plane through a capacitor [1000pf, 1KV]. I can understand why you might ...
0
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2answers
156 views

How to isolate two ground signals?

I'm have grounding problems (80% sure of it). I have an MPU6050(gyro sensor which works on 3.3V) which is powered by the Arduino's 3.3V pin and SCA,SCL,INT pins are used with the I2C bus of the ...
2
votes
1answer
62 views

Is this ground plane correct?

I am trying to improve my grounding skills This is a RJ45 connector on one side, a signal transformer, and a pin header on the other side (this is a prototype, and i am splitting the design in parts ...
4
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1answer
69 views

common mode ground

My doubt pertains to a certain document/app note about common mode and differential grounds- Link1 and Link2. What I read about common mode noise is that it is a noise generated on all signal lines ...
2
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3answers
202 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. ...
2
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4answers
76 views

Multiple Ground Referenced Sensors on Single Floating Supply

Some background: I'm designing an industrial control board with isolated analog and digital IO. The hope is for it to be pretty foolproof, such that you could connect any 4-20 mA or 0-5V sensor with ...
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1answer
40 views

Grounding of a PCB that communicates with a PC via USB or RS232

I have a PCB with an atmega8, communicating with a PC. The signal from TX and RX pins is level-shifted through a MAX232 to standard serial port level, then converted via serial-to-USB commercial ...
0
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1answer
82 views

Effects of unearthed PSU and shielding on audio 50Hz hum

I am trying to get a good understanding on sources of 50 Hz “ground hum” interference in audio equipment and good practices for shielding and grounding by making hum on purpose and taking steps to ...
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4answers
195 views

Tape recorder head has only 2 pins, which one is for grounding?

I am trying to make my own cassette adapter that will help me play my music on my iPod through my car stereo system that supports only cassettes. For that I've bought a 3.5mm earphone jack and a ...
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0answers
53 views

ESD - SMA connector

Suppose I have PCB in metal chassis with 2 SMA connectors mounted on it. Let's say they are used for GSM and GPS. How to protect against ESD and successfully pas FCC/CE? I couldn't find any TVS ...
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1answer
50 views

Where do the return currents go for a MCU with multiple Vdd and grounds?

I am reading this article on mixed signal design: https://www.maximintegrated.com/en/app-notes/index.mvp/id/5450 When signals have really high speed, the return current will tend to follow right ...
5
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4answers
442 views

For Multiple ADC circuits PCB layout grounding, why is “single point ground” important?

I am reading this article from Maxim on mixed-signal circuits grounding: https://www.maximintegrated.com/en/app-notes/index.mvp/id/5450 Everything makes sense to me until I read the "Grounding ...
5
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2answers
421 views

How do compact AM radios establish a ground?

I am trying to construct a radio and, at the first stage, I have finally detected circuit a signal. My previous attempts have failed and I have discovered that it is because it was not properly ...
0
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2answers
120 views

Is there a reason why some ac/dc adapters don't have a grounding pin?

I'm searching for an AC/DC adapter of 6v 300mA, but I can't find one with a grounding pin (E-type). Is there a specific reason for this?
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1answer
68 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 ...
0
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1answer
75 views

Can I place a regulator in this way?

The regulator supports both digital circuits and analog circuits, which is shown in the diagram below. My question is: can I place the regulator at the analog part? The regulator supplies the ...
5
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2answers
170 views

How on earth shall I design the ground planes for mixed signal circuits, split or not?

Our circuit is like following: There are four layers, including top, power, ground and bottom. My way of grounding: I follow the instruction by Maxim: ...
2
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1answer
76 views

Best practices for stitching vias

I am designing a four layer board with a grounded copper pour on the top layer. I had my board reviewed by a 3rd party and one of their comments was that the via on the South side of C41 was ...
2
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1answer
88 views

Multiple ground planes with optocoupler

I'm designing a circuit that uses an optocoupler to isolate a relatively noisy H bridge from the USB circuitry also present on the board. Clearly in this case I will have two grounds - what is the ...
0
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1answer
104 views

Basic questions about chassis grounding

I am uncomfortable with the notion of chassis ground but I can't pin down what exactly bugs me. So I'll start with an example and ask a couple of questions on the way. My background is this: I have ...
0
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0answers
86 views

How to shield an isolated battery powered system?

I'm currently in the process of "designing" (selecting) a DC-DC Converter solution for a battery powered widget that will operate in the desert. It has to comply with various aspects of ...
2
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1answer
74 views

Chassis Grounding a Bipolar Floating Power Supply

I'm building a simple function generator powered from a 24V AC wall adapter. I've rectified the incoming AC to 24V DC using a full wave bridge and an LM317. I intend to split the supply into +/-12V ...
5
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3answers
204 views

For a 4 layers PCB (with ground plane), covering with ground polygon on Layer 1&4 necessary?

For a single or double layered PCB board, usually I will cover all the empty spaces in the layout with Ground. This is the 1st time I am designing a 4 layer PCB layout. Layer 1: top signal (high ...
0
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0answers
62 views

Are input and output grounds shorted in regulators/battery eliminator circuits?

I am new to electronics and I'm curious about something: Would there be any voltage between the input GND of a regulator (or a BEC), and it's output GND? In other words, is GND the same everywhere in ...
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0answers
70 views

Which Ground Should I Use for my Function Generator Circuit

The broad question is, which ground should I use for my function generator and why. Some background, I'm trying to build a function generator based on the XR2206 IC. I've looked at a few circuits at ...
3
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1answer
295 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 ...
0
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1answer
219 views

What happens if there is a fault in the neutral wire between the grounding pole and the centre tap of the transformer?

I was reading through some SE questions/answers on residential power transmission and came up with two scenarios I'm unsure about: Assume that your house is wired properly (with no degradation), but ...
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1answer
115 views

Connecting grounds when using an isolated DC/DC converter

I am designing a PCB that needs to convert 24V DC to 5V DC @ 8 amps. I would like to use an off-the-shelf converter and virtually everything in that range is an isolated DC-DC converter. Is there any ...
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1answer
109 views

Mixed signal Microcontroller grounding

I have a circuit with split ground planes one for analog, and one for microcontroller/DC-DC etc. The microcontroller will be using its ADC to sample from the analog circuitry. Ideally I would like to ...
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1answer
362 views

Measuring an analogue voltage with isolated ground

I am working with a solar EV (car), and I need to measure the throttle pedal signal. The throttle peddle is essentially a 10k ohm pot between 5v and gnd on the motor controller. (0-5V signal). As ...