My favorite recently was when I didn't realize my pet rabbit ate the power
cord for the cable box in the living room. I found it alright. I had to tape
that up, comcast will love to get that one back. It was more than I should
have just taped but oh well. I got a nice jolt from that one.
----- Original Message -----
From: "colin McDonald" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, February 28, 2011 8:13 PM
Subject: Re: RFI Saga continued
> and while I know we all learn, and are taught about treating electricity
> with caution, and respect, and that how it takes x amount of tiny current
> at
> x amount of voltage to potentially stop the heart etc etc, you can still
> grab onto an open 110/120VAC line and it'll only give you a bit of a
> jolt...I've gotten that so many times I can't count from bad wall plugs
> and
> bad chord ends etc...try plugging the vehicle in at minus 25 when the
> female
> end of the extention chord has been lying in the snow and you have to get
> rid of the snow plugging up the plug to insert the male part from the
> vehicle...you get jolted a few times doing that let me tell you...though
> after a few minutes, your fingers are numb enough from the cold that you
> don't really feel it anyway hi hi.
> at any rate, when your working on devices that have a step down
> transformer
> in them, best practice is to unplug, or turn the power off if you don't
> need
> the device to be operational while your working on it...however, if it is
> unavoidable, like in this situation, there's not much harm in getting a
> little buzz if you touch the wrong spot.
> Also, if you unplug the thing and explore around inside before working on
> it
> while it's live, you can orient yourself to where the higher AC voltage
> might be located. These days, most components have some sort of
> insulation
> around the high voltage contact points...such as at switches and where the
> AC connects to fuses and the main transformer.
> Usually these things are designed with all the high voltage, as in 120VAC,
> connections set up on one side of the PCB...sometimes I just put
> electrical
> tape or duct tape over these connections if they are open so I don't touch
> them or short them or something like that.
> It's easy to tell these connections because the wire is generally pretty
> thick compared to other wiring in the device, and you can trace the wire
> and
> tape off solder points or whatever.
> there is always a way, if there is the will.
> I've been working on a solid state guitar amp lately. In order to trouble
> shoot the problem, it has to be turned on and operational in order for me
> to
> figure it out. I traced all the hot spots and covered them with
> tape...and,
> I know where the hot spots are located on the board so I stay away from
> that
> area as much as possible. I also taped the edges of the board and the
> chassis edges so nothing will short to ground by accident while the board
> is
> floating around unanchored.
> I did this of course after I shorted some hot point to the chassis, which
> is
> ground in this thing..and had a little flash and puff of
> smoke...thankfully
> nothing blew and all is well, other than the original issue.
> So, respect power, and maintain considerate caution, but don't fear what
> isn't there.
> I mean, don't stick your tongue on a live 120Vac source or anything, but
> getting a tingle in your fingers from accidentally touching it isn't going
> to hurt you or your equipment in any severe manner.
> Allot of guys will use a rubber matt on the desk and floor while working
> on
> anything that is live...but again, not all that is necesary unless your
> dealing with allot of humidity in the air or you have a real high ground
> potential or high electrical resistance in your body.
> everyone will react differently to electricity as well depending upon
> their
> biological make up.
> 73
> Colin, V A6BKX
> ----- Original Message -----
> From: "Butch Bussen" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Monday, February 28, 2011 5:03 PM
> Subject: Re: RFI Saga continued
>
>
>> You're making a mountain out of a mole hill. It won't bite you!!!
>> Turning the switch on does nothing but connect the primary to a c. Just
>> unplug and it will bleed off in half a minute or so. I've worked on
>> them plugged in for years.
>> 73
>> Butch
>> WA0VJR
>>
>> On Mon, 28 Feb 2011, tom behler wrote:
>>
>>> The other thing I was thinking of doing was unplugging the power
>>> supply,
>>> letting it set for a while, and then turning the switch on, in the hopes
>>> that this would help discharge the capacitors too.
>>>
>>> Any thoughts?
>>>
>>> 73 from Tom Behler: KB8TYJ
>>>
>>> ----- Original Message -----
>>> From: "Butch Bussen" <[log in to unmask]>
>>> To: <[log in to unmask]>
>>> Sent: Monday, February 28, 2011 11:57 AM
>>> Subject: Re: RFI Saga continued
>>>
>>>
>>> The thing will discharge itself if you let it set a short while.
>>> Second,
>>> there is only 24 volts or so on a cap and I've worked on them hot and as
>>> long as you stay out of the primary 110 side, no worries. It won't zap
>>> you.
>>> 73
>>> Butch
>>> WA0VJR
>>>
>>>
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