Ground or earth is the reference point in an electrical circuit from which other voltages are measured, or is a common return path for electric current, or a direct physical connection to the Earth.
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Breadboards and ground loops
The book Practical Electronics by Scherz and Monk states (3rd ed., p 48):
A ground bus, or bus bar found in breadboards... serves as an adequate substitute for a single point ground.
Is this ...
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2answers
75 views
Best practice to switch +V or GND connection?
Consider LAMP1 and LAMP2 in the simple example circuit below:
Which is the "better" practice, using the switching component ...
7
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3answers
176 views
Use of ground symbols in circuit diagrams
In this question is the following diagram for a voltage booster intended for small battery powered devices
The TPS61200 spec says GND is control/logic ground and PGND is power ground but this isn't ...
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1answer
33 views
Choosing a ground for ltspice circuit
I am just getting into this software. I construct my circuit, and it tells me to choose a ground. I only have experience with "ideal" circuits and circuit elements, and have only seen "ground" in the ...
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2answers
281 views
Can you send data usefully over one wire, literally one wire?
It is possible to design networking systems that only use two wires: one for data and one for a common ground. Examples include 1-wire and Pin&Play. These are called single wire systems because ...
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2answers
92 views
Why are leads from the negative terminal considered grounds?
I'm using a 9V battery with a 5v regulator as a power supply. What I can't grasp is why I place the regulator in the (+) lead of the battery. If electricity is electrons flowing, and the excess ...
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1answer
85 views
Ground Fault Question Regarding a 3 Phase Circuit
I'm needing to design a 3 phase ground fault detection system for a 480V system. It will need to be able to trip when there's ground fault current >1A.
I have done some reading and it sounds like ...
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2answers
156 views
Do 2 5V DC wall warts in the same AC outlet have a common DC ground?
I'm trying to power a LED strand from one wart (5V), and my logic driver FPGA from another wart (also 5V). Both warts are plugged into the same outlet strip. I know I should probably power them from ...
3
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1answer
109 views
Power Plane and Decoupling Capacitors Routing
Forgive me for my simplicity. I'm just a hobbyist and not an engineer by trade.
I am trying to make my first 4 layer PCB in Eagle and I have a question I cannot find the answer to regarding power ...
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2answers
167 views
Transistors never work for me
TOday, I have built an LED cube. I put it all together, arduino, mess of wires and all, and it doesn't work. Fiddling with it a little bit, I find that if I short certain wires to ground, the LED's ...
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2answers
87 views
DC Voltage Grounded with AC Input
This is an image from a book showing us how to solve BJT circuits via AC analysis:
So I understand that when doing AC analysis to ground all the DC voltage sources but I don't understand why. Can ...
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1answer
100 views
Tying multiple power supply grounds
I'm planning on a home automation system, and two sub-sections will be separated by (say) 100 feet. These will be connected by a low-amp, low-voltage data connection. To avoid running significant ...
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3answers
174 views
Ground on Breadboard
I need to connect an input signal from a function generator to a circuit I made on a breadboard.
If I use a BNC to Banana cable, then would the "ground" of the function generator (the ground on the ...
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1answer
95 views
What's the use of ground coupling on digital oscilloscopes?
What's the practical use of ground coupling on modern DSOs? I know that it can be useful on analog oscilloscopes to adjust the ground exactly to a graticule line, but from what I've seen, most of the ...
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1answer
93 views
How do I wire a relay board into existing series recepticles
I have a four channel relay, that I'm going to attempt to wire into a terminal block. I have experience with mains wiring and some experience with electronics, but no experience wiring relays. ...
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2answers
173 views
bridge rectifier connected to a raspberry pi gpio
I'd like to connect a bridge (full wave) rectifier to my Raspberry Pi (RPi), GPIO pin 22 (configured as an input). I have configured the rectifier such that it has a 120VAC input and 3VDC output (I ...
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1answer
77 views
How do I connect a signal shield to minimise noise from close proximity AC
In my proposed application, I will have approximately 30 RS-485 nodes configured in 3 chains spaced ~1m apart. There is a need to pass through 240v L-N-E, +5v, A, B, GND in each node. The physical ...
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1answer
137 views
How does this heavily oxidized copper-to-steel joint work in earthing?
Wikipedia article on grounding features this photo:
Here's a close-up of the joint:
Clearly the steel rod is heavily oxidized and the copper wire is oxidized. The clamp is coated with something ...
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2answers
197 views
Grounding and why charge leakage occurs
A basic nugget of info is missing in my end-to-end picture of how grounding works and why it's important. When a voltage is applied in a circuit the electric current starts flowing (or the field ...
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1answer
124 views
Two power sources, common ground and noise
I'm having the following circuit:
Where TWL6030 is a DC-DC buck converter and INA219 is a high side current sensing circuit.
My problem is with the power sources,...
3
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2answers
172 views
Grounding in circuit diagrams
Often I see in circuit diagrams that the circuit is connected to the ground:
I understand that this creates a reference for zero potential, but why does all of the current not simply flow right ...
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1answer
688 views
Y USB Cable with external 5V supply
I just got a brand new Nexus 4 phone and am a bit dissappointed that it doesn't support USB OTG. One reason is that is doesn't supply 5 V out of its USB port, as opposed to other Android devices I ...
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1answer
80 views
Confused about the way this speaker is wired
From this article:
I don't understand why one end of the speaker is connected to the + of the battery. If the output of the 555 goes into one end of the speaker, shouldn't the other end of the ...
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1answer
214 views
What is ground and what does it do?
I'm a bit confused about the concept of ground, and perhaps voltage as well, particularly when trying to analyze a circuit. When I learned about Ohm's law in grade school, I learned how to apply the ...
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1answer
217 views
How is the following ground symbol different from conventional ground?
I've seen the following ground symbol in quite a few schematics:
How is this different from the typical GND symbol?
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1answer
84 views
Is using Same Ground and VDD for MCU and motor driver module safe?
Im trying to design an MCU prototyping board. i have 2 voltage regulators (3.3 and 5V) and motor driver on my board. All grounds are common, VDD of MCU comes from 3.3v reg and power supply for motor ...
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1answer
121 views
Shared GND on 2 ATX Power Supplies
I'm constructing a custom(cheap) power supply, with digital current meters and such.
I'm using 2 ATX power supplies to build it. I'm using 1 for the standard -12, -5, +3.3, +5, +12 outputs. I've ...
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2answers
373 views
How do you properly ground a digital pot and an op-amp?
I'm going to take a 5V 500mA power supply and pass it through a digital potentiometer AD5235 and then step it up through an op-amp with a gain 2 to get up to 10V output and put that into voltage based ...
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4answers
175 views
Common ground and voltages, Part 2
To further my understanding of what happens when 2 circuits have a common ground could someone please explain what happens when the following 2 circuits (charged capacitor, high resistance load) :
...
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3answers
364 views
Common ground and voltages
Further to a question I asked earlier, I realised that common ground confuses me. I have a USB powered Arduino and a separate Battery supply. The battery supply negative is connected to the Arduino ...
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1answer
168 views
Ground noise and voltage drop problem
I have an RC device powered by a 3.7V poly battery, which includes a motor and a 40KHz sonar. The voltage across the sonar sensor is amplified and then adc-ed. The motor is driven by a 2KHz PWM.
When ...
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1answer
185 views
USB ground on MSP430 Launchpad interfering with Comparator_A input voltage
I'm trying to read an audio signal from an Android phone as a serial input to an MSP430G2553, adapting this design to use the MSP430's onboard comparator module instead of an LM324. The Android code ...
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1answer
118 views
What is the right way to understand the behaviour of shocking voltage?
I am just a starter and I am reading some beginner material about electricity.
I have some problem understanding this page which was about shock current path.
The writer explained why the bird is ...
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1answer
211 views
Why high voltage from TV flyback shocks you without the need to complete a circuit?
Assuming the TV is plugged into an isolation transformer (although I think there is already a small transformer onboard), then ground is not part of the secondary side. Yet, high voltage from flyback ...
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2answers
353 views
Can we connect battery negative terminal to oscilloscope ground?
I want to test my setup with 200Ah battery and check the outputs on oscilloscope. While testing can I connect battery ground to the oscilloscope ground?
Is there any safety risk, as oscilloscope ...
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1answer
147 views
Ground question
Beginner here. I am working on a project using a Sure amplifier and noticed there is a ground label on one of the holes used for mounting. Do I need to do anything special for this? The link below ...
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1answer
302 views
How to connect ground planes together
What is the best way to connect ground planes together ?
I know that ground planes are connected together at multiple locations in order to keep a low impedance GND across the whole board and provide ...
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4answers
511 views
Difference between negative terminal and copper ground?
What is the difference between Negative a ground? Like a negative terminal and a copper ground? I was reading that they are both the same; one person stated that negative is just more negative than ...
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1answer
80 views
Purpose of negative bias reference generator
I am working on a redesign and there is a negative bias generator on the ADC in the circuit. (not the circuit below) I am pretty sure that the small negative voltage instead of ground is there to ...
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2answers
175 views
Ground loop issue on my sound card
So if I build up a lot of static and put on my headphones, it creates this loop in the circuit or whatever and produces constant static until i somehow ground it out. It has even shocked me on the ...
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2answers
144 views
Should old electronics be polarized?
On old electronics that don't have a polarized power cord, what would be the benefits of adding a 2.2Mohm resistor from one side of the a/c to the chassis and switching out to a polarized cord ...
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1answer
286 views
PCB practices: Grounding, and interaction b/w switching and control loops
This is kind of 3rd in a series, following the posts Advice on ground plane in my first PCB and then Separating ground planes in PCBs. In terms of material, though, it can be considered a post on its ...
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1answer
359 views
Separating ground planes in PCBs
This is in a way a follow up to my previous post Advice on ground plane in my first PCB. I wanted to continue my questions there, and I updated my post after receiving feedback from others, but ...
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2answers
243 views
How is this crystal / ferrite bead / ground shield connected?
This is part of the schematic for a TI TAS1020B USB Streaming Controller MCU that I don't quite understand. Obviously the shield connects to one end of the ferrite bead, but what else? Are the XTAL ...
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3answers
480 views
Advice on ground plane in my first PCB
I needed some advice on my first ever PCB. I am trying to build the circuit below (schematic drawn using OrCAD Capture), which is straight out of the datasheet of the flyback controller LT3748.
I ...
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2answers
142 views
Can current be drawn from ground in a SWER transmission setup?
I am almost certain that this is a ridiculous question, but cannot figure out why this scenario would not work.
From what I understand, current from the electrical station is distributed to houses ...
6
votes
1answer
459 views
op-amps: where to split the rail?
I have been experimenting with op-amp audio amplifiers powered from a 9V battery. I am just wondering how I should go about splitting the voltage from the battery, as I have found 2 ways of doing this ...
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2answers
134 views
Ground copper pour for Crystals and Real time clocks
I am laying out a (2-layer) board, with a standard SMD Crystal as well as a Real-time clock placed on the top-side of the board.
What are guidelines regarding ground copper pour under the Crystal and ...
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2answers
67 views
*EP pin connect to Ground
I was just wondering what is the function of the *EP pin on most TQFN package chips?
It says I should connect EP to ground, what happens if I don't ground it (I forgot)?
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1answer
168 views
Why ground is positive on this part?
I'm using a powered device controller (PD is what they call a device that receives power over Ethernet), and its pins and way of connecting things is really weird. This part, LTC4265, takes in power ...
