Once again I must plead ignorance: Could someone please tell me what an RCD
is?

Thanks,

Sean

At 07:48 AM 9/14/99 +1200, you wrote:
>All this out of my head - probably approximately correct but don't trust
>your life to it:
>
>Defibrillation (or more properly here, fibrillation) depends not only on
>current but also on duration. RCDs are designed to disconnect power within a
>critical period. I think it's within 50mS (which fortunately makes sense in
>the context of 50Hz (or higher) mains frequencies) and corresponds to a
>critical period during the heart's cycle. In fibrillation the normal voltage
>patterns of the heart are disturbed and while it may still oscillate it may
>subsequently do so in a  mode which is not conducive to pumping blood. The
>television (and real life) "300, joules, clear, zap" routine is designed to
>polarise the muscle, clear all oscillation patterns and let the oscillator
>try and start clean again. (Master Reset).
>
>As you'll well appreciate if you've "field tested" one, an RCD does not stop
>you receiving a shock (the kick is not necessarily pleasant) but strictly
>limits the duration.
>
>
>
>RM
>
>
>
>From: G.C. <gary.cadman@TIUK.TI.COM>
>
>>I think that these figures air on the side of caution. An RCD usually has a
>trip of 30mA all though you can get them in many sizes.
>>When I last looked at these type of figures I recall a statement that 30mA
>at 40V was sufficient to cause defiblaration.
>>
>>Jim Main wrote:
>>>
>>> I found the following pertinent info in a mag the other day, detailing
>>> whether or not you'd be able to let go a live source - it depends on the
>>> amount of current that's flowing through the muscle.. and gave the
>following
>>> rough guidelines..
>>>
>>> 1mA   - tingling feeling - no problem letting go
>>>
>>> 10mA - probably still able to let go
>>>
>>> 16mA - borderline able to let go
>>>
>>> 20mA - you're locked to it!
>>>
>>> Jim
>
|
| Sean Breheny
| Amateur Radio Callsign: KA3YXM
| Electrical Engineering Student
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