Re: [Z_Scale] Re: Z SCALE
- thank you
how come my meter reads 14v dc on a marklin z power pack with no load on the track when model max is 8v dc
can i isolate the other rail by putting a cut in the uncut rail on a marklin 8588 isolation track or will that not work
--- On Tue, 8/3/10, Alan Cox <alan@...> wrote:
> From: Alan Cox <alan@...>
> Subject: Re: [Z_Scale] Re: Z SCALE
> To: firstname.lastname@example.org
> Date: Tuesday, August 3, 2010, 5:04 PM
> > what i dont understand is when
> both loops are in difference directions then i have the plus
> side of one pack connected to the neg side of the other pack
> via the common rail why dont i get a short?
> Short answer: because electricity doesn't work like that -
> it's all
> relative. So providing there is only one side cross
> connected anywhere
> (which is the case with a common return and Märklin
> controllers as they
> each have their own transformer) then if you join them
> together one one
> side that simply becomes a common voltage between the two.
> Join both
> together and bad things happen.
> If you join one side together and then connect a voltmeter
> across the
> other two you'd see a voltage that varied according to how
> you turned the
> knobs. With one on zero and the other turned you will see
> the voltage for
> that one (-8 to +8 or thereabouts), turn them both the same
> way and you
> will see a low voltage or even 0 if they were turned the
> same amount.
> That is of course the normal case when you run a train
> between loops -
> there is little voltage difference between the two loops.
> The bad case is if you turn the knobs in opposite
> directions, you will
> then see up to + or -16v on the voltmeter, which is more
> than the models
> are designed to take in normal use.
> They are a good deal more robust than you might think
> however because
> they are designed to survive a variety of situations where
> the model
> carries more power than you would like - just as they get a
> amount of 'will it bounce' considered in the design
> Other scenarios that are usually considered in designing
> models include
> - derailment where one truck comes off the track and ends
> up with the
> wheels shorting the other rail. At this point the
> short is through the
> wires in the locomotive
> - Similarly where a locomotive moves from one section to
> another which
> already contains a locomotive that is currently not
> being fed power. At
> that point the second locomotive is potentially
> being powered through
> the wiring of the first.
> - Running through electrofrog points the wrong way
> - Putting a locomotive using overhead on the track the
> wrong way around
> But 16v across a model designed for 8 isn't very good for
> it - especially
> if its more than briefly.
> Z-scale: minimum siZe, MAXIMUM enjoyment!
> Yahoo! Groups Links
- On Tue, 3 Aug 2010 13:34:11 -0700 (PDT)
Tony Dalileo <tony_mrr@...> wrote:
> thank youPut a load on it.
> how come my meter reads 14v dc on a marklin z power pack with no load on the track when model max is 8v dc
The newer ones are also quite smart and don't simply output 0-8v smoothed
DC but know how to give better motor control than that.