Questions tagged [grounding]

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

19
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2answers
2k views

Why does connecting a high-current device to my digital circuit cause weird behavior?

I have a arduino microcontroller other digital thing and when I connect a motor pump heater other high current thing I experience weird ADC measurements reboots crashes errors in digital ...
3
votes
1answer
1k views

Would I need a star topology with a dedicated ground plane?

Some background: I have a PCB with a bunch of relays on it. The purpose of the circuit, is to allow signals to pass through from one connector to another (db37), or to stop it - that's where the ...
2
votes
2answers
2k views

Ground Loop for balanced connection

Different articles and tutorials covers somewhat contradictory information about ground loop. For a balanced connection (differential), the return path is the other differential pair, however ...
3
votes
2answers
383 views

3 SMPS in one board

I'm doing a PCB where there are 3 SMPS: one boost(12v to 48v, 1 amp max) and one buck converter(5v to 4v, 4 amps max) functioning at the same frequency(same timer in microcontroller). the other ...
4
votes
1answer
2k views

How to safely use the power-socket ground for the anti static wrist strap?

I saw as practice to use the power-socket ground for the anti static wrist strap, I saw this done where there is no available specially designed ground for anti-static pads and bracelets, but this may ...
15
votes
2answers
2k views

Grounding PCB to enclosure

I am designing a small sensor which fits into a custom aluminum enclosure. The sensor uses CAN bus and a long cable to connect it to the host and power. The shield of the cable will ground the ...
2
votes
3answers
982 views

Using an OEM power supply

I am trying to use an 12V OEM type power supply to supply 12V to stepper motors through an L293 h bridge in an Arduino powered circuit but my current setup starts burning all the negative wires and ...
1
vote
5answers
3k views

Why can't you use the ground of a second DC power supply as a return?

This is probably a really silly question, but I can't seem to find the answer anywhere. Say I have two totally separate DC power supplies running from AC power, and another piece of equipment that ...
11
votes
3answers
1k views

What is mecca ground?

I came across few different ground names (digital, analog, signal, power, mecca, EM, shield, etc). I do understand most of them - but mecca is a new one for me. Can someone please explain this mecca ...
12
votes
3answers
5k views

Coaxial cable signal and ground

How does a coaxial cable carry RF, audio and low freq. signals? I understand there must be a difference between all these, for example the return path being through the shield or not. Can someone ...
-1
votes
1answer
457 views

Exclude GND trace from GND groundplane in Eagle

I have a board layout in Eagle with a groundplane. Now I have a trace inside of this groundplane which is also GND but this one shouldn't merged into the groundplane. The reason is, that i want to ...
0
votes
1answer
132 views

Is grounding needed when using adapter to phone?

I am doing research on an audio plug. I wonder, is it a must to connect grounding circuit from handphone to the earphone if we use an adapter (image 1). Or can I do the connection like in image 2? ...
4
votes
1answer
584 views

Why bridge the GND wire on a DE-9 connector?

Why would someone want to bridge the GND wire to the metal shield of a DE-9 connector? Take a look at the picture below. A 10 position flat ribbon cable is soldered to a DE-9 connector (male). On ...
1
vote
1answer
253 views

UART receive only works if I have a oscope or voltmeter attached to it

I designed a board to interface the CEL MeshConnect Mini Zigbee module with a lighting controller board. The Zigbee module is able to transmit bytes via UART and I've verified this, but the radio ...
4
votes
3answers
14k views

Positive and negative potential via two power supplies with common ground?

I need to use a positive and negative potential on a circuit including an instrumentation amplifier. My lab only has single supply power supplies (only offers positive voltage). I know that I can ...
8
votes
4answers
11k views

Why is this laptop adapter grounded?

This adapter is clearly not capable of delivering a null, a power and a ground to the laptop because the connector only has two surfaces. The adapter itself is plastic. So why is it grounded? (Note ...
4
votes
2answers
2k views

Surface Pro grounding issue

I have a Microsoft Surface Pro tablet which, when charging from the included power adapter, gives a slight tingling feeling when touching anywhere on the Magnesium shell. This is a commonly reported ...
6
votes
1answer
423 views

Why do some devices have 200V on the case?

I recently got a desktop LED lamp, and I feel a "strange" slight vibration when touching the metal case. I found that other devices also have high voltage on their case. What is the reason/trade-off ...
1
vote
3answers
377 views

How bad can an unconnected ground be?

My collegue here has two seperate boards linked by an SPI link. He just asked me: "So... you need to connect the grounds?" After I picked myself off the floor and answered very much in the affirmative,...
1
vote
1answer
231 views

Ground coupling a high voltage source with the A_GND and D_GND

I have a device that measures the current in the mains through a 0.01 Ohm 20W shunt resistor. The voltage across the shunt is amplified by a op amp and feed into a uC's ADC for farther calculations. ...
3
votes
1answer
2k views

What is a 'quiet ground' / 'Ground plane'

I really don't expect an analytic answer. I'm sure there are far too many variables to consider. I'm working with a fairly simple circuit (Precision voltage, Instrument amplifier) but need to really ...
1
vote
1answer
2k views

5V 1A from 24VAC transformer with grounded secondary

I built a power supply for a micro-controller board that requires 5VDC and peak of 1A (typically sits at 500mA). The power supply has an input of 24VAC. I used a bridge rectifier and an LM2575-5 ...
13
votes
1answer
1k views

Is it possible to reject noise traveling on the outside of a coaxial transmission line?

Say I have some ordinary coax between a receiver and an antenna. That coax will have three currents in it: the desired signal an exactly equal an opposite current on the inside of the shield (really, ...
7
votes
1answer
2k views

Placement/routing of decoupling cap straddling oscillator guard ring on dsPIC

Changes in my design are forcing me to replace my 44-pin dsPIC33FFJ16MC304 with a 64-pin (same package size, finer pin pitch) dsPIC33FJ64MC506. In the datasheets for both chips, Microchip recommends a ...
3
votes
1answer
844 views

Oscilloscope ground clips sparks while connecting to power supply

Oscilloscope ground clips sparks while connecting to power supply ground. I do understand The clip is connected to earth ground. But why does it not spark when I am powering a circuit of the supply?
7
votes
4answers
4k views

How to handle unused wire in cable

What is the best way to handle an unused wire inside of a cable. Let's assume I've got a cable with 4 wires, only 3 of them are used. I could connect the 4th wire at one end to ground, at both ends ...
0
votes
1answer
1k 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 like ...
13
votes
3answers
18k 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 ...
8
votes
2answers
4k views

Grounding Metal Object to Eliminate Static Electricity Using Electrical Ground

let us say that I have built a metal cabinet in which I will be painting small objects. I am looking to eliminate any static electricity that could possibly build on the object to be painted or on the ...
3
votes
2answers
4k views

Ethernet phy connection: grounding between chassis, connector and IO

The phy chip I'm using has a evaluation board which grounds the chassis, connector and signal gnd points in the following way: However, I don't really understand why the MCTx connections are ...
8
votes
1answer
1k 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?
10
votes
3answers
1k views

What do I do with the extra “ground chassis” tab on a DC power jack?

Product Link Datasheet I have about fifteen 9v wall warts within specs for the circuit; I'm going to use the one that fits the jack. There are three solder tabs on the jack. One for the positive tip,...
9
votes
2answers
5k views

Recommended way to connect the exposed pad to ground pins

Is it okay to connect the exposed pad to the ground pins as in the image below, or is there a recommended way to do it?
13
votes
6answers
48k views

How to safely ground a switching power supply with floating outputs?

I just received a 120VAC to 5VDC (20A) switching power supply (the kind with a passively ventilated metal casing) for use with a microcontroller project I'm working on (driving long LED strips). I've ...
2
votes
2answers
441 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 it wouldn't work. From what I understand, current from the electrical station is distributed to houses through power ...
1
vote
1answer
709 views

Help with grounding a generator on a running vehicle

Ok, this may be basic, but I can't seem to find a solid answer. If I have an AC generator in use on-board a running vehicle (that is being driven), is a GFCI enough or must some sort of grounding be ...
4
votes
2answers
224 views

grounding connection?

What's the easiest way to connect a ring terminal to the ground terminal of an AC outlet? Are there plugs you can buy that make this easy? I don't need (or want) the line and neutral wires accessible,...
23
votes
4answers
4k views

Why the arc when bonding-on during high voltage repairs?

When working on high voltage power-lines via helicopter the technician will "bond-on" with a steel wand called a hot-stick. During this process an arc is conducted from the line to the wand. Now, ...
2
votes
2answers
6k views

Grounding a DIY power supply

I am trying to develop a bench power supply. Now, before going on, I do realize that there are really cheap commercial ones available. I have two. I want to develop one my self. The way I have ...
6
votes
2answers
890 views

Why do TQFP and TFQN have different advice regarding analog ground?

This question is in reference to How to split Analog and Digital GND planes for a TQFN device. For the PSoC3, the advice on how to separate the analog and digital ground is different depending on the ...
1
vote
2answers
1k views

How to split Analog and Digital GND planes for a TQFN device

This question is in reference to Mixed signal PCB layout for PSoC. If I am using a microcontroller which has separate analog and digital supply inputs and GNDs, what should do with the grounds? ...
1
vote
0answers
106 views

Ground problems in kitchen [closed]

i have had some trouble in my kitchen recently about some tingling stingy feeling while touching the kitchen sink. and stove metal. my toughts is that here is some ground problems but I could not ...
4
votes
2answers
1k views

Captive Nut For PCB Grounding

I need to affix a ground strap to my PCB. A strap similar to . Ideally I want to simply screw this to the board. Are there captive nuts available for this purpose? I can't find anything via a ...
20
votes
4answers
19k views

When to use ground plane cutouts?

I've been reading more about proper grounding techniques and using ground planes. From what I've read, ground planes provide a large capacitance with adjacent layers, faster heat dissipation, and ...
38
votes
2answers
30k views

Competing PCB Crystal layout recommendations

This is related to this question: How's my crystal oscillator layout? I'm trying to layout a 12MHz crystal for a micro controller. I've been reading through several recommendations specifically for ...
9
votes
2answers
15k views

How to check if something is mains earth grounded?

Suppose I would like to verify that the ground terminal on an indoor power outlet is actually connected to the ground (from what I've read, some of them aren't!). How would I go about checking that? ...
6
votes
1answer
876 views

Sending ground along with digital connections between boards

I have been wondering for quite a while whether it's good practice when connecting two boards together (powered from the same power supply, although each has its own regulator) to send ground ...
7
votes
2answers
470 views

Grounding Shielded Panel-Mount Connectors

I'm building an amplifier in a conductive metal chassis. The general grounding plan is to have an audio ground, a power ground, and a digital ground that converge at a single point on the chassis. ...
17
votes
1answer
10k views

With shielded twisted pair cable, do you ground one end, both ends, or neither ends of the shield

I've got a project coming up that's to be doing RS-485 communications over shielded twisted pair cable. The project will involve cable length runs of many 10s of ft and the cables will probably have ...
0
votes
2answers
262 views

High voltage metallic shield grounding

What size of conductor I have to use to ground the shield of a high voltage cable? I would guess that the size of the grounding conductor is related to the size of the cable, but I'm not sure.