Questions tagged [grounding]

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

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Why is there a voltage between the mains ground and my radiator?

I have an anti-static mat that comes with a plug that only has a ground lead. Out of curiosity, I measured the voltages between the live, neutral, ground, and my radiator. As expected, there is ...
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0answers
22 views

Extension cord from grid through GFCI outlet to off grid inverter. Does the extension cord ground need connected?

I have an off grid system: PV, charge controllers, inverters, and batteries. I want to add a 120V grid input from a GFCI outlet through an extension cord directly into the inverter AC input. However, ...
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1answer
45 views

NPN Transistor Switching 12V - grounds with different potential

I'm struggling with a NPN transistor switching problem, and in the process I've burned out a board elsewhere in my machine. Electronics is not my strong suit. I want to use a 5V signal to switch 12V. ...
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0answers
44 views

Bootleg grounds on residential 2 wire 110v electric circuits

I bought a old duplex house with 2 wire electric circuits and 3 prong outlets. A home inspection found the outlets had no ground,the seller agreed to having an electrician "rectify" this condition ...
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0answers
31 views

shunt resistor with solar panel

I'm wondering whether the connection of the shunt resistor in this image is correct? and not having any grounding problems? Because i have already connected my shunt resistor with solar panel and ...
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1answer
48 views

how to make different grounding

yesterday when i ask about driving circuit, someone told me that it is a little use in optocoupler when i use the same ground everywhere. because so far (iam a green hand in electronic) i just connect ...
0
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1answer
54 views

Wiring a traffic light

So I have aquired 1 light of a traffic light that I salvaged from a local dump. I want to try and connect the light to use it like a lamp, however I am a little worried by it as the connector only has ...
4
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1answer
154 views

PCB design review: analog routing

I am designing a PCB with analog signals for the first time, and I would really appreciate any feedback on my layout and routing. The circuit is a light-meter, consisting of a photodiode connected ...
0
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1answer
53 views

How do you monitor communications on a positive-grounded device from a negative-grounded desktop?

I have a need to read the signals being sent between two boards in a lighting fixture. In preparing to do this I have read much about the chips, RS485, and analysers/decoders that are out there. I am ...
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1answer
55 views

Amplification of a Microphone with a LED Array and speaker: Grounds? [closed]

This is the circuit I'm trying to build: Circuit on falstad.com I feel like everything works in theory, but I'm having trouble implementing the grounds on the actual circuit. I do not know where to ...
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2answers
54 views

Shield grounding location for an STP cable in a balanced system

If a balanced source or driver is coupled to a differential balanced receiver via a balanced STP cable as shown in the hand drawn illustration below: in such case I have read that grounding the ...
2
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1answer
54 views

Common ground on a switch mode power supply

I've got a switch mode power supply and I have a question on the grounding of the PCB. Documentation on the PSU can be found here: https://docs-emea.rs-online.com/webdocs/1621/0900766b81621ef9.pdf ...
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0answers
61 views

Connecting the secondary side of ignition coil to earth

I have an ignition system used for some application. During the testing I found that spark plug is producing EMI due to spark occurrence and high voltage is traveling through the wire. So to ...
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1answer
165 views

Proper Chassis Grounding

I'm starting to design things that run off mains voltage and I want to be sure that I have a proper connection from my chassis to earth ground. I've been reading a bit about proper grounding and have ...
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2answers
132 views

Ground, common, and Earth ground confusion

I am learning on transmitters and input modules nowadays. But the usage of word 'ground' is confusing me. What does 'ground' mean there (earth or power supply common)? If it is earth ground, why we ...
2
votes
1answer
76 views

ESD Grounding Straps with No Chassis Ground

I've got water pump device that needs to pass ESD testing (IEC 61000-4-2, 8kV contact, 15kV air discharge). On this device (as circled in red), there are these four metal inlets. At 2kV with an ...
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0answers
60 views

Grounding the components of a DIY cnc machine

I'm in the process of building a DIY cnc machine. It already runs, but I noticed it has some interference problems (steppers act weird on occasions, the full graphic smart controller LCD has trouble ...
0
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1answer
129 views

Earth connection on this single phase AC motor

I bought a drill press recently that comes equipped with a 0.5HP single phase AC motor. I have wired it up as per the instructions that came pasted on the motor but I do not see a terminal for earth ...
2
votes
1answer
964 views

Why put capacitor between ground and chassis?

In the product I analyse (an optical fork sensor, rated 10V-35V), there is a sizewise big capacitor between ground and chassis. I measured its value with an LCR meter, it is 60nF. I also broke one by ...
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1answer
115 views

DC floating ground and TVS Diodes for ESD

I want to provide ESD protection for a low voltage battery powered device and I do not understand what sort of net I should attach to the cathode side of the TVS diodes: I do not have a strong ...
3
votes
1answer
203 views

Shield in Inner Copper Layer

I have been designing second version of 4 Layer PCB. The PCB has connectors all over the PCB. In the first version, I had Copper Pour (I call it ...
0
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2answers
75 views

Not Understanding Grounding in an Electrical Circuit

This might be a stupid question but i am just a little confused about grounding/earthing. Specifically for example in a home when some electrical appliance faults, the current will go to ground since ...
0
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1answer
97 views

Why not keep distribution transformers secondaries floating? Why do we need to earth them?

We use isolation transformers for many reasons, one of them is may be safety. So why not just keep the distribution transformers floating? If they're floating, then someone touches the live wire, I ...
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1answer
52 views

Can leakage current to ground generate static electricity?

I'm having a weird issue at my workplace where some industrial equipment is present. Almost every time I leave my laptop (with grounded aluminum body) for a while and come back I will get a quite ...
0
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1answer
55 views

Device's ground riding on a non-ground signal

The question is somewhat conceptual, feel free to close if it's too off-topic. If I take my portable (battery-powered) oscilloscope and try to measure the mains voltage, the connection polarity ...
0
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1answer
40 views

Digital signal integrity & grounding

I have a battery operated device with an old B&W LCD in it. I'm tapping to the display bus and would like to input it into an FPGA for some processing. The bus includes vertical and horizontal ...
2
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1answer
97 views

Earth Ground Portable Generator

I recently bought a pure sine wave 2kV portable generator to use for camping. In the manual it states that the generator should be grounded to actual earth through a metal stake and then attached to ...
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1answer
84 views

Noise on my oscilloscope when probing a wire

I am prototyping a NTC voltage divider circuit and I am having trouble with noise on my probe. It seems like I am constantly getting a large amount of noise (200-300mv) on my oscilloscope waveform ...
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2answers
170 views

Ground something, for a short time

I need some simple solution, for grounding an AdKey for a short time lets say 200ms, only once, on each power on. I don´t know the exact needed time so it would be nice if i can change the time with ...
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0answers
47 views

Why doesn't current leak to ground (DC)? [duplicate]

In the circuit shown below, I am considering ground to be ideal earth ground (stays at 0V no matter how much current it absorbs). It is my understanding that current flows when there is a potential ...
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3answers
86 views

Sensor damage, ground loop or something else?

We are testing an capacitive fuel level sensor in field. Its mounted on top of a heavy construction vehicle (colmar) with a 24v battery system. Our sensor runs for few weeks and damages. Every time a ...
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0answers
42 views

Odd Ground/Power(?) issue with Mixing Desk - alternate grounding?

I am a bit stumped with this one. Unfortunately there are a few variables involved, but I will do my best to ask an answerable question.... I just built a DIY synthesizer. It functions absolutely ...
0
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1answer
57 views

Question on Ground/Neutral connection for a 220V equipment

I sketched the following schematic from a motor controller board that has to be operated at 220V from L1 to L2. The earth wire is connected to the chassis of the machine. Where I live, it's common to ...
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1answer
53 views

What is the relationship between Ground Potential Rise (GPR) and Source Voltage?

I am looking at the results for an earth grid study for a 50Hz substation. Primary Voltage (Vp) = 11,000V Secondary Voltage (Vs) = 415V Secondary Fault Current (If)= 24kA Secondary Grid Current (...
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0answers
100 views

How to line a Metal Melter secondary for higher safety

A Metal Melter is a kind of home-made low voltage (less than 40 volts, mine is 3v) welder (small-scale) made from a microwave oven transformer (MOT). I left the primary intact (the thicker wire, which ...
0
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1answer
117 views

Power supply and pcb connections to ground, earth

I am planning a pcb which is powered by two switching power supplies LRS-150F-5 (230 V/AC to 5 V/DC) LRS-150F-12 (230 V/AC to 12 V/DC) . The power supplies are mounted in their own metal box and the ...
0
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1answer
54 views

How to safely connect USB to TTL (FTDI) adapter to device and also use bench power supply?

I'm trying to flash new firmware onto an ESP8266EX chip. The chip requires 3.3v and 80 mA (average). My USB to TTL programmer (FTDI chipset) can supply 3.3v but only at 50 mA. Here is what I'm ...
0
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1answer
515 views

Measured continuity between live and neutral

I was trying to get rid of the humming noise coming from my speakers in my hi-fi system. It is an old piece of equipment from back when the UK appliances did not come with the mains plug and you had ...
0
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1answer
72 views

Is this soldering iron and power supply combo grounded and if so, how?

I'm interested in a TS100 soldering iron as a decent starter iron and a light one that doesn't take up too much space. It doesn't come with a power supply though, presumably to keep it flexible as it ...
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0answers
99 views

Earthing for Satellite Dish

A friend who is an electrical engineer (heavy current) told me to earth my satellite dish and its fixing pole against lightning, using a thick copper cable (6 sq.mm) and an earth spike. He also said ...
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0answers
177 views

Flyback Transformer - Grounding the Ferrite Core

Today I dismantled (I hope this is the correct verb) a flyback transformer. The thing that I've never seen is that one end of one of the windings is "glued" to the ferrite core (Before you ask; yes, ...
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1answer
112 views

Do I definitely not want to to add a ground wire to this UART connection?

I'm in a bit of a quandary here but it must be a common one. I have two boards powered from the same battery through a "Y" cable; both boards have voltage regulators on-board. These boards are ...
0
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1answer
122 views

Separate ground for gate opener control box?

Is it worth electrically isolating the control box of a gate opener from a well grounded steel fence? Or does the grounding of the fence have the same effect? My house is in a very lightning prone ...
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3answers
132 views

Why does low power factor make my LED bulb and clock radio flicker at 0.2 to 3 Hz?

[California, USA, regular 110 V power.] I'm reading the power factor of my "Late 2013" 27-inch iMac using a P3 P4400 Kill-A-Watt. It reads 0.95 when operating normally (60 to 120 W), but when ...
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0answers
85 views

PCB Grounding Plane Review

I am reviewing a 6 layer board that has analog signals on the left and right side of the board. I have always read that analog circuitry should be grouped together for easy plane segmentation. ...
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1answer
61 views

Can a ground fault be caused by something outside the home?

Yesterday afternoon, I had a GFCI switch trip. It would not reset. I figured I had a ground fault. I left the home for a few hours and after I returned I was able to successfully reset the GFCI. The ...
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3answers
71 views

where to place grounds on a circuit

I'm used to seeing circuit schematics with single/no grounds at all (drawn by teachers and some tutors) but now, I see circuits with multiple grounds. My question is, when drawing a particular ...
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2answers
471 views

What is the purpose of this extra PCB pad?

I am looking to use this crystal in an upcoming design and I am a little bit confused by the datasheet. The datasheet is available here: CMR200T Datasheet This is the image in question: Question: ...
2
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1answer
50 views

Analog ground/Digital ground question

I am designing a four layer PCB, (signal, ground, pwr, signal), which is to generate +-1V max 30kHz frequency signals which is output on a differential pair. It is pretty simple board layout but I am ...
0
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1answer
53 views

Why is there a grounding clip on this solder sucker instead of a third prong on the plug?

As most of these inexpensive tools tend to omit the ground altogether (such as in soldering irons), why would ground be added as a clip instead of a third prong? Is there an advantage for it to be ...