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Where to hookup the antistatic wrist strap on board a boat? — Parallax Forums

Where to hookup the antistatic wrist strap on board a boat?

electrosyselectrosys Posts: 212
edited 2010-07-10 03:06 in General Discussion
Hello all,

Like most of you, I use an antistatic wrist stap to prevent eletrostatic discharge (ESD) ruin the ICs and eletronic circuits. The problem is that I live onboard a boat and don't really know where to connect/ground my wrist strop! As for now·I have connected my wrist strop to the boat's mast steel wires, but I'm not really sure that aluminium mast and the steel wires are good enough to prevent an static·discharge, any idea where or how I could ground my wirst strop on board?


Antistatic-Wrist-Strap-KS-102-.jpg

Comments

  • wjsteelewjsteele Posts: 697
    edited 2010-07-09 09:11
    Your boats electrical system has a ground bus somewhere, you can attach it there or to any piece of electrical equipments case. Do you get much static electric build-up on a boat, like for example rubbing your shoes on the carpet? If you can force it, then you can simply touch something to see if it shocks you... if it does, then that's a good grounding point.

    BTW... my Dad invented that grounding strap!!! He actually invented it for something totally different, a heart rate monitor, but also wrote in the patent appliation as a side note that it could also be used as a ground strap to protect delicate electronic CMOS equipment when it was first being experimented with.

    Bill
  • John R.John R. Posts: 1,376
    edited 2010-07-09 14:14
    electrosys said...
    Hello all,

    Like most of you,
    Huh?· How many folks actually use one?

    Setting that aside, the point of a "real" ESD system is to make sure that all components and user are at the same "ground level".· If that level is "earth ground" or 1000 volts above "earth ground", it really doesn't matter, as long as everything and everyone is at the same level.

    So, on your boat, if there is a 120 volt system, you could use that·"ground", or use·the negative·(usually black)·side of the 12/24 volt system.· The important thing is to have all items (chasis, anti-static mats, wrist straps, etc.) tied to the same point/bus.

    Be careful of using just the case of a piece of equipment.· Sometimes the cases of marine equipment are very much isolated from what's inside to protect from water, moisture, algae, vibration/bouncing,·etc.·· Some of this stuff is not built like "normal" electronics in many ways.· I seem to recall someone saying that water and electricity don't mix...

    For others reading, in terms of "marine" (meaning fresh and salt water) equipment, you see a complete spectrum of "quality" ranging from a bilge pump that may, or may not, last a single season to some very "exotically" packaged equipment that could be submerged 100s of feet in salt water, and come out fine.· Price is also not always the determining factor (on either end).· Lots of neat surprises to be had...

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    John R.
    Click here to see my Nomad Build Log

    Post Edited (John R.) : 7/9/2010 2:22:36 PM GMT
  • Mike GreenMike Green Posts: 23,101
    edited 2010-07-09 14:21
    On a boat, the equivalent to "ground" is the water. Any boat with a radio system will have a ground, either the hull if metal or a metal plate on the hull if fiberglass or some other insulator.
  • John R.John R. Posts: 1,376
    edited 2010-07-09 14:22
    wjsteele said...
    BTW... my Dad invented that grounding strap!!! He actually invented it for something totally different, a heart rate monitor, but also wrote in the patent appliation as a side note that it could also be used as a ground strap to protect delicate electronic CMOS equipment when it was first being experimented with.

    Bill
    I'm thinking there could have been lotsw of "fun" during the testing process for the static discharge part of things...

    How do you/can you use these things as a heart monitor?

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    John R.
    Click here to see my Nomad Build Log
  • John R.John R. Posts: 1,376
    edited 2010-07-09 14:25
    Mike Green said...
    On a boat, the equivalent to "ground" is the water. Any boat with a radio system will have a ground, either the hull if metal or a metal plate on the hull if fiberglass or some other insulator.
    Not necessarily - some of the marine band radios are installed just like a CB, mount the chasis in the fiberglass console, +/- 12 (24) VDC, and connect the co-ax to the antenna, no metal plates, etc.·

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    John R.
    Click here to see my Nomad Build Log
  • Peter KG6LSEPeter KG6LSE Posts: 1,383
    edited 2010-07-09 14:35
    wjsteele said...

    BTW... my Dad invented that grounding strap!!! He actually invented it for something totally different, a heart rate monitor,

    OMG I have used the straps only with my 3 lead ECG /wrist /wrist / leg monitor ..
    I figured they were not sticky like pads . and not as hard to find..



    Peter KG6LSE

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    "Carpe Ducktum" "seize the tape!!"
    peterthethinker.com/tesla/Venom/Venom.html
    Never underestimate the bandwidth of a station wagon full of tapes hurtling down the highway. —Tanenbaum, Andrew S.
    LOL

    Post Edited (Peter KG6LSE) : 7/10/2010 5:13:53 AM GMT
  • Cluso99Cluso99 Posts: 18,069
    edited 2010-07-09 14:50
    electrosys: Just use the negative of the 12V system, presuming it is 12V. What sort of boat is it? We lived on our cat for 4+ years although now I guess I spend 50/50 on/off the boat though my wife hasn't been onboard for over a year. Our boat is interstate and that is where I stay when I am up there.
    Not all boats have earth plates as such. However, the engine will be grounded and that in turn will be grounded to the sea via either a leg or prop shaft.

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  • wjsteelewjsteele Posts: 697
    edited 2010-07-09 14:56
    John R. said...
    I'm thinking there could have been lotsw of "fun" during the testing process for the static discharge part of things...
    Yes, that's where vandagraph generators come in handy. An interesting thing is they were testing them with "anti-personal bomblet" radar systems they developed (he worked at Avco) in the late 60's. The new Radars were so small (about the size of a quarter) that they needed to be built with the new CMOS technology... and obviously they were destroying a bunch of them due to the lack of knowledge about CMOS's sensitivity to ESD.
    John R. said...
    How do you/can you use these things as a heart monitor?
    When he started working on the heart rate monitor using CMOS, he also realized they could use the same system as a sensor because of they way it worked. The wriststrap was used as a pickup lead for a signal that was transmitted to some other part of the body, usually the chest. Modern excerise equipment uses this type of device now, for example most high end wristwatch heart rate monitors also come with a chest strap. Some are even built into clothes. His idea was specifically for battlefield scenerios, where it might be impossible, impractical or uncomfortable to attach leads elsewhere.

    Bill
  • Mike GreenMike Green Posts: 23,101
    edited 2010-07-09 15:03
    "vandagraph" = Van de Graaff

    Do a web search for "wiki Van de Graaff" for details
  • SeariderSearider Posts: 290
    edited 2010-07-09 19:35
    I suspect that the humidity level on a boat is high enough that there is little risk of ESD. I rarely use a wrist strap except when the humidity is very low or I am putting something together that I will sell. I cant remember the last time I had an unexplained chip failure. I am careful, don't put parts on plastic, touch metal or other grounds before cicuit boards etc ...

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    Searider
  • wjsteelewjsteele Posts: 697
    edited 2010-07-09 19:53
    Mike Green said...
    "vandagraph" = Van de Graaff

    I must have been asleep! smile.gif

    Bill
  • Cluso99Cluso99 Posts: 18,069
    edited 2010-07-10 01:35
    Searider: No, you will sometimes get a static discharge.

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    Links to other interesting threads:

    · Home of the MultiBladeProps: TriBlade,·RamBlade,·SixBlade, website
    · Single Board Computer:·3 Propeller ICs·and a·TriBladeProp board (ZiCog Z80 Emulator)
    · Prop Tools under Development or Completed (Index)
    · Emulators: CPUs Z80 etc; Micros Altair etc;· Terminals·VT100 etc; (Index) ZiCog (Z80) , MoCog (6809)·
    · Prop OS: SphinxOS·, PropDos , PropCmd··· Search the Propeller forums·(uses advanced Google search)
    My cruising website is: ·www.bluemagic.biz·· MultiBlade Props: www.cluso.bluemagic.biz
  • James NewmanJames Newman Posts: 133
    edited 2010-07-10 03:06
    Ground is just a commonly decided reference point. There are safety reasons for this, but they are mainly based on scenarios dealing with shorts. It also makes it convenient when all of your supplies have a common.

    As said above, just make sure your strap(you) and the work piece are strapped to the same thing. Something big and metal is good. Something that is big and metal and is also electrically common to the water is great.
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