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

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64 views

Converting 2 pin plug into a 3 pin grounded plug [on hold]

I have a portable power socket that accepts two 2 pin power plugs and 1 pin 3 pin grounded power plug. There is a hole on one side of this portable power socket where the wire goes into. Oddly this ...
1
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1answer
35 views

Mixed Signal Grounding: Which approach will yield better isolation and analog performance?

I'm laying out a mixed signal PCB and I'm trying to decide between (1) separating the ground planes for the digital and analog/digital circuits completely [shown in top figure] or (2) keeping the two ...
1
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0answers
46 views

four layer analog board, should I pour ground on top and bottom layer?

I am now designing one four layer analog board for 24-bits ADC based bio-potential signal acquisition. I have ground and power plane on the second and third layers. Most of the analog signal traces ...
0
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2answers
86 views

DC circuit schematic has both positive and negative supply as well as ground?

I am trying to breadboard a DC circuit schematic (a sawtooth voltage controlled oscillator, to be precise). In the schematic there is a positive supply, a negative supply and ground (+4.5V, -4.5V and ...
3
votes
1answer
59 views

Oscilloscope Probe Noise and Safety

I have a Tektronix 531A tube oscilloscope from the late 50s. I recently bought some 20$ probes and noticed a lot of noise on the 0.005 volt/cm setting when that spring loaded hook attachment was ...
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3answers
80 views

Aluminum sheet as an underlay for electonic equipment

I am planning to build a NAS into a (sufficiently ventilated) closet. For flame protection and heat spreading, I mean to put a 2x700x550mm aluminum sheet under the equipment. Is this a good idea? ...
2
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2answers
77 views

Can ground plane EMIT noise?

I have 3 separate grounds in my project: AGND - Analog ground is very quiet, very small relatively smooth currents PGND - Power ground used for power bypass caps and power supply related circuitry ...
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2answers
123 views

What are design considerations for grounding an enclosed AC-to-DC converter?

Here I'm talking about a device that takes 100-240V AC in, and outputs 10-20V DC out. In terms of grounding, I'm referring to the grounding offered by a standard outlet (e.g., a NEMA-5-15R receptacle)....
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3answers
78 views

Connect anti-static wrist strap to earth wire?

I have started doing some hobby electronics at home and got myself an anti-static srtist strap recently. I am unsure as to where to attach it to. Most topics I found online regarded PC building and ...
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1answer
68 views

Ground my body to DC (USB) [closed]

Does grounding body to DC power source makes sense, to get rid of any electrostatic(?) charges from my skin/body ? In my new house, when I'm standing on the floor, connect voltage meter (AC) and ...
2
votes
1answer
52 views

How to connect GND between both sides of a signal transformer

I am doing a test board to learn more about ethernet, differential pairs, etc. I understand that the transformer will isolate my board from the world. But I wonder how to design the termination ...
2
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0answers
93 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 ...
4
votes
1answer
84 views

What is the point of seperating analog ground and digital ground if they are going to meet at the end

First off, I'm fairly new to electronics, I don't have much knowledge so bear with me. I saw a schematic of an ADC connection to an MCU, and I noticed that the grounds are split into two - Analog and ...
4
votes
4answers
112 views

Hot and neutral have similar voltage to ground - finding the problem

I have an APC battery backup and surge protector for my computer. It has a light, labeled "Building wiring fault." This light is on, and my computer will not start. I am unemployed and my landlord is ...
0
votes
1answer
57 views

Common ground between a current source and a power supply

I want to design a simple circuitry for testing a bench top current source through a load resistor. I want to use MAX9611, and read data through I2C by a micro-controller. The rough circuit schematic ...
0
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2answers
77 views

System Grounding and Mixed Supply Grounding

I'm attempting to prototype this curve tracer (http://www.vintage-radio.info/download.php?id=224) mainly following the original design, but altering it to suit my own requirements (serial connection ...
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2answers
49 views

Can i use 2 prong power cord for my desktop computer? [closed]

Are there any chances it may damage my computer?
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3answers
312 views

RS485 network ground pin - when to connect?

As many know, one can implement a simple node to node rs485 communication by using only two wires, A and B. Well, the standard specify to connect the ground of the two node together. from Wikipedia: ...
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1answer
51 views

External Power Supply Grounding Scheme

The following are two possible grounding schemes for a sensitive instrument that contains high gain analog circuits and potentially noisey digital circuits: This circuit is connected to an external ...
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0answers
35 views

System not working as expected - resistance measurement

I found a problem while measuring the resistance from PCB1. When both the FETs are enabled on System 1,the resistance is measured. PCB1 is powered from USB port 1 and system 1 is powered from ac-dc ...
0
votes
1answer
24 views

dsPICDEM MCHV-2 Development Board motor connection

I have dsPICDEM MCHV-2 Development Board and three phase induction motor. I don't know how to connect the motor to the development board. I have connected three lead wires of the motor to the three ...
9
votes
3answers
145 views

How can I ensure low-resistance ground contacts to an aluminum enclosure?

I am building an electronics project with an aluminum enclosure. I need to ground it—and very well—for human safety. (The system handles 300 A of current, and I want to be sure that if there is an ...
4
votes
2answers
80 views

How does Hybrid Ground Works?

The text that is above the figure is from my textbook and i am having difficulty to understand what it is trying to say because it's not in detail!! why only remove high frequency and prevent low ...
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2answers
77 views

Why should we couple AGND and DGND?

we can see the connection at the right hand side between the DGND and AGND! according to my course text,"the real electronic ground of the system is where the point AGND and DGND are coupled." but it ...
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0answers
77 views

Computer motherboard grounding, is it possible to short my motherboard doing this?

Some information: I essentially have a custom created case that I believe is sheet aluminum. and have placed a mini itx mobo inside. Since the case is very small, I wanted to buy small standoffs. ...
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votes
1answer
113 views

Do DC current can be earthed? [closed]

If I take a 12 V battery and connected its (+) terminal with the (+) wire of a load and connected the negative wire from the load to the ground (earthing). I have heard that earthing absorbs current ...
6
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2answers
113 views

What constitutes a “sufficient” ground?

Electricity novice here. Thanks for reading! I have a 3000 watt DC to AC inverter attached to a 12V battery bank. The inverter has "DC ground lug" on the exterior of the inverter's case which the ...
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2answers
123 views

GND in a DC circuit with circuit board

I wonder a question. Let's say I use a circuit board in a project (the left hand side on image below, not the Verabod), and I want to solder a circuit on it. For example, I want to use the circuit ...
0
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0answers
53 views

Power planes, virtual grounds, and ground loops in mixed signal 4 layer pcb

I'm a hobbyist and really need some help with a project I've been working on. I have a four layer PCB with analogue and digital parts. The ground power plane is split between them but with a join ...
0
votes
1answer
70 views

Ground potential not at zero in 30y old apartment

I am living in an about 30 years old apartment in China. Sometimes when I am touching my Mac Book (aluminium case) I would get little electric shocks. I measured the voltage between my Mac Book case ...
0
votes
1answer
80 views

how to differentiate the gnd audio to gnd of battery?

i'm new to the forum. I have some problem to Connect this device with one single battery. I think the problem is on the connection of the max4466 electret. It has a common ground and it make me ...
4
votes
2answers
142 views

What are reasons for NOT connecting exposed pad (EP/thermal pad) to ground?

For what reasons would a manufacturer suggest that the thermal pad should NOT be connected to ground? See link and snippet from a Nordic datasheet. https://www.nordicsemi.com/eng/nordic/...
11
votes
3answers
414 views

Why an electrician wiring error could make a PC's USB shield be at 120V when it should be grounded

I almost had a serious electrical accident last week when I was trying to use an oscilloscope to test out a circuit a student had built. I had the scope plugged into a floor outlet, and the circuit ...
4
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1answer
77 views

Grounding Scheme for Signal + Power

Background I am working on a project which requires a both digital and analogue signals along with power and biases to be connected between two devices over roughly 1 metre is quite a harsh (magnetic ...
4
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2answers
127 views

Avoiding ground loops

I'm a little stumped by how to avoid ground loops. I need to connect to a mostly analog external component that requires VCC_12V, VCC_5V, VCC_3V3, VCC_N7V (\$-7.0V\$) and GND. I assume the external ...
0
votes
2answers
69 views

where the extra electricy in earthing goes? [closed]

excuse me I'm newbie in electricity , can you please explain how electric will go through one cable that is connected to an earthing rod that is not connected to the circuit or the system being ...
0
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1answer
94 views

How to ground the below circuit when I use USB?

I am constructing the circuit given below: The problem, however, is that when I connect the electrodes to my skin, I get a mild shock. I am powering the Arduino using an USB cable. I connected the ...
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2answers
69 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
114 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
votes
1answer
67 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
31 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
votes
4answers
795 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. ...
0
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1answer
50 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, ...
3
votes
2answers
175 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 ...
0
votes
1answer
67 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 ...
1
vote
2answers
55 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 ...
22
votes
5answers
6k 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
74 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
380 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 ...
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2answers
2k 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 ...