Re: component electrical specifications?
John,
That reed switch is rated for only 300 mA @ 30 V.? If you have multiple locos, sound loco, etc or a short circuit you might have problems especially if it ever switches while under load?
|
Re: component electrical specifications?
Robin, I have a "lift" gate that I protect with magnetic reed switches, such as used in alarm systems.? You can easily find them by searching for the item below on Amazon.? I use one on each end, running the rail feeder (drop) through the switch, which is closed when the gate, or bridge, is down.??
John
7939WG-WH - Ademco Surface Mount Contacts
|
Nope, you've completely missed it, Jim.? I want to reverse the
entire staging area and it's approach tracks, including the
passing sidings.? All as a unit.? Based on the position of one set
of switches, which the operators set as a single action.
But, given it's size, I want CB protection of the yard to be
separate from the approach and siding trackage.?
I'm not sure what I can say to 'turn your head upside down', as
this is what I've been saying all along.
Respectfully,
Blair
On 2021-08-18 20:49, Jim Betz wrote:
toggle quoted message
Show quoted text
Blair,
? Your track plan is very "complex" and your "reversing sections"
are (if I understand
how you intend them to work) -very- short (as in just the
cross-over area?).? That?
seems, to me, to be a design for "impossible".? You -may- be able
to redefine how
you wire it in order to avoid the reversing section nemesis ... a
reversing section
that is shorter than the longest train going thru it.? If the
train is too long sooner or
later (and usually sooner) the wheels will be crossing the gaps on
both ends of
the reversing section.??
? You also added in a statement about "up to 4 trains all moving
at once" - which?
further increases the probability (inevitability) that you will
have the gaps at both
ends of the reversing section closed (gapped by the wheels).
? I'm afraid the above is the best I can do on this one.? I.e.
Warnings, warnings,
warnings.? Running one train at a time it probably works but this
seems like a
"double reversing section that is also overlapping another
reversing section".
? Here is what I recommend - do what you think works then TEST.?
Test first
with only one train, then add additional trains until you "max
out".? If you
don't have problems then great.
? One last thing to consider ... are you creating something that
"only works if
the operator(s) do all the right stuff at just the right times"??
If you track plan
-and- wiring depends upon humans never making a mistake - you will
have
problems.? Not only with boomers - but even with your regular crew
and/or
family and/or just you.
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
? ? ? ? ? ? ? ? ? ? ? ? - Jim?
|
Blair,
? Your track plan is very "complex" and your "reversing sections" are (if I understand
how you intend them to work) -very- short (as in just the cross-over area?).? That?
seems, to me, to be a design for "impossible".? You -may- be able to redefine how
you wire it in order to avoid the reversing section nemesis ... a reversing section
that is shorter than the longest train going thru it.? If the train is too long sooner or
later (and usually sooner) the wheels will be crossing the gaps on both ends of
the reversing section.??
? You also added in a statement about "up to 4 trains all moving at once" - which?
further increases the probability (inevitability) that you will have the gaps at both
ends of the reversing section closed (gapped by the wheels).
? I'm afraid the above is the best I can do on this one.? I.e. Warnings, warnings,
warnings.? Running one train at a time it probably works but this seems like a
"double reversing section that is also overlapping another reversing section".
? Here is what I recommend - do what you think works then TEST.? Test first
with only one train, then add additional trains until you "max out".? If you
don't have problems then great.
? One last thing to consider ... are you creating something that "only works if
the operator(s) do all the right stuff at just the right times"?? If you track plan
-and- wiring depends upon humans never making a mistake - you will have
problems.? Not only with boomers - but even with your regular crew and/or
family and/or just you.
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? - Jim?
|
Re: Block Detection for signalling and automation
The easy way for signaling is to make the turnout and points part of the mainline signal block leading up to it. Both of the tracks leading away from the frog should be isolated and start the next signal blocks. If one of them is a siding it does not need to be separately sensed. Your signaling logic may want to include the turnout position.
DonV
|
Re: component electrical specifications?
Voltage depends on your scale, i
I believe it can be up to 27 Volts or so for larger scales per the DCC specs.?? Current depends on the command station or circuit breaker that is feeding your switch and I think you would want to be able to handle short circuit current without your switch failing.
Robin
Robin Becker
San Diego CA
https://DRGW.n3ix.com
|
Re: Block Detection for signalling and automation
Blair there is a great new book out about signaling. Guide to signals and interlocking by Dave abeles. It pretty much tell you everything you need to know. Kalmbach publishing issued the book.
|
Re: DCC Bus reversing question
Wouter
Thanks.? A PSX-AR is capable of reversing all of an 8A booster, so I think I'm safe even if I went that route.? Agreed, other AR units don't have the same specs.? I think reversing the feed upstream of a pair of PSX units is going to be my chosen action. Whether I achieve that with a solid state reverser, or with a DPDT 10A relay, is still open.
Blair
toggle quoted message
Show quoted text
On 2021-08-18 16:31, whmvd wrote: Blair,
In all your deliberations, do not forget that all autoreversers also have their own maximum sustainable track current.
Wouter
_._,_._,_
|
Re: DCC Bus reversing question
Blair,
In all your deliberations, do not forget that all autoreversers also have their own maximum sustainable track current.
Wouter
On Wed, 18 Aug 2021 at 19:47, Blair < smithbr@...> wrote:
Thanks for the generic DCC reversing how to, Jim; I'm sure it is
well intentioned.? Doesn't address my question exactly, but others
will benefit.
I have to reverse a large area of my layout(up to 16 trains);
that area is driven by it's own booster, BUT I want multiple
sub-sections protected by SS breakers.? Though each track of my
staging can be shut off, the upshot is I could have up to 4
multi-unit trains running simultaneously in the yard and
approaches.? I want those trains to proceed without a glitch when
I change the alignment of the |X|, so the reversing needs to be
solid state.? I also want the yard and the approach tracks on
separate circuit breakers.? So I see my booster either reversing
and feeding breakers, or feeding an autoreverser* which then feeds
two or more breakers.?
Your description of your layout is similar, though smaller I
expect, than my situation.
The autoreverser must be FASTER than the circuit breakers in
order to reverse before they act, else it won't act.? If the short
is sustained (i.e. not resolved by the AR), then I want the
circuit breakers to act BEFORE the AR swaps the polarity again; I
strongly suspect the AR actions will suppress the sensing of a
short by the breakers, resetting their timing.? So I don't think
this will work well - I expect it will flip-flip-flip ad nauseum.?
Alternatives:
- Reverse the Loconet Railsync signals, which you don't seem to
like, but which I see no fundamental issue with, or
- use an autoreverser that can be triggered externally by the
same signal driving the tortoises on the |X|.? I can't quite see
how to do this using the PSX-AR, but I may just have misread the
manual.? Comments appreciated if someone has done this.
I'm presently reviewing my staging plan to see if I can identify
a single stretch of track in each approach that could be
considered a "reversing section" of it's own, thus allowing the
staging yard itself to be fixed polarity.? Problem is, if I do
that, I think I can still have multiple trains entering/leaving it
simultaneously, due to the layout, which wouldn't be acceptable.?
These concerns are what resulted in my "flip-it-all based on one
crossover state" approach.
Blair
On 2021-08-08 20:39, Jim Betz wrote:
Blair/Don ... and all,
? You don't need to re-invent the wheel.? DCC works just fine as
designed.? DCC wiring - if
you follow Gartner's recommendations - is also easy and fool proof
(if you follow them
correctly).? Specific responses:
? 1) No you don't need to swap railsync wires - and you shouldn't
do so.
? 2) Yes, you can use some kind of physical switch to "rewire"
reversing
? ? ? ?sections.? Most guys like the automated aspect of a
Reversing DCC
? ? ? ?circuit breaker.
? 3) The best (in my opinion) DCC circuit breakers are the PSX
series.? They
? ? ? ?work and work well.? They were designed with sound in
mind.? They are
? ? ? ?electronic (which makes them fast).? Yes, they cost a bit
more than?
? ? ? ?other brands of DCC circuit breaker - yes, they are worth
it.
? 4) A reversing section should not be up against another
reversing section if
? ? ? you are using DCC circuit breakers.? They end up trying to
out guess each
? ? ? other - and that competition usually goes on forever.? You
can, with some
? ? ? breakers, set a different trip speed to prevent this ... but
it is better to not
? ? ? have two reversing sections next to each other.? This is
almost always
? ? ? possible thru careful selection of where your breaker
boundaries are.
? 5) A reversing section should be "longer than the longest train
you will
? ? ? ever run thru it".? It does not have to be "the entire loop"
- but most guys
? ? ? will set it up that way and it's usually easier.? Another
way to say this one
? ? ? is "you don't want both ends of the train - or two trains at
once - crossing
? ? ? the reversing section".? Again, the breaker gets confused
and, in this case,
? ? ? ends up competing with itself.
? Reversing breakers work like this:
? a) Situation normal.
? b) A short occurs.
? c) The breaker -temporarily- tries reversing the polarity of the
reversing
? ? ? section.
? d) If that works it leaves it alone and the train continues to
run.
? e) If it didn't work then you have an "actual short" and the
breaker goes
? ? ? into "there's a short" status.
? f) Most modern DCC circuit breakers also have an automated
Retry.
? ? ?They will wait a second or two and then retest to see if the
short is
? ? ?still there - this is what allows you to throw the switch and
"clear the
? ? ?short".
? On my layout I have just one reversing section - it is the huge
loop in
staging - the staging is 5 tracks wide and 3 trains long.? All
trains enter
(and exit) staging thru just one track that goes to a switch.? All
of the
track past that switch is both Staging and the reversing loop.? I
have it
wired with just one circuit breaker.? If it ends up that there are
too many
trains in staging (amp draw too high) I will cut the power to some
of the
tracks (the ones that the turnouts make "unavailable".
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? - Jim
??
|
Re: component electrical specifications?
I'd go for something with a 5A rating, Dave; "overkill" is better than "marginal".? Voltage is only about 15V, so pretty much anything will do that way.? I presume what you're doing is removing the DCC signal from the bus feeding the tracks on both sides of the bridge.? In that case, remember, you only need to interrupt one of the signals, not both.? Don't ask how I know...
Blair
toggle quoted message
Show quoted text
On 8/18/2021 6:25 PM, Dave Emery via groups.io wrote: I want to use microswitches on a drop-gate to power track (when the gate is up). There¡¯s lots of different kinds and power (voltage/current) specifications. What¡¯s the recommended min rating for a switch handling DCC?
Thanks!
dave
|
component electrical specifications?
I want to use microswitches on a drop-gate to power track (when the gate is up). There¡¯s lots of different kinds and power (voltage/current) specifications. What¡¯s the recommended min rating for a switch handling DCC?
Thanks!
dave
|
|
|
Re: DCC Bus reversing question
In the photos area, under my name, as we now can't load JPG files to the files area.
Blair
toggle quoted message
Show quoted text
On 2021-08-18 18:09, Blair wrote: oops. I forgot, this list strips attachments.
See Sketch "loop schematic e.jpg" in the files.? It'll be there momentarily.
Blair
On 2021-08-18 18:00, Blair wrote:
Attached is a rudimentary sketch to illustrate my staging yard. (remember, there are two such, very similar).
You can see, I hope , how it makes sense to me to simply reverse the entire B/C loop section, and thereby avoid other complications.? I looked at using an AR for each approach, e.g. L to N, or even just M to N, and similarly Q or R to S; in each case, there are use cases where the reversing block thus created could have a train entering and leaving.? Only the crossover bottleneck presents a single, unambiguous reverse vs don't-reverse use case.
I think, on the whole, reversing the booster would be best, if only the booster fed only sections B and C.? However, given that I still have hopes of initially running both staging areas from one booster, as shown, that option is off the table, leaving me with only one - reverse using a DPDT relay dedicated to each staging yard, as shown.? I don't want to use an AR here, as an AR will be used for track section D, and it will be connected to B, forming the dreaded "adjacent AR" conundrum.
Blair
|
Re: DCC Bus reversing question
oops.? I forgot, this list strips attachments.
See Sketch "loop schematic e.jpg" in the files.? It'll be there momentarily.
Blair
toggle quoted message
Show quoted text
On 2021-08-18 18:00, Blair wrote: Attached is a rudimentary sketch to illustrate my staging yard. (remember, there are two such, very similar).
You can see, I hope , how it makes sense to me to simply reverse the entire B/C loop section, and thereby avoid other complications.? I looked at using an AR for each approach, e.g. L to N, or even just M to N, and similarly Q or R to S; in each case, there are use cases where the reversing block thus created could have a train entering and leaving.? Only the crossover bottleneck presents a single, unambiguous reverse vs don't-reverse use case.
I think, on the whole, reversing the booster would be best, if only the booster fed only sections B and C.? However, given that I still have hopes of initially running both staging areas from one booster, as shown, that option is off the table, leaving me with only one - reverse using a DPDT relay dedicated to each staging yard, as shown.? I don't want to use an AR here, as an AR will be used for track section D, and it will be connected to B, forming the dreaded "adjacent AR" conundrum.
Blair
|
Re: DCC Bus reversing question
Attached is a rudimentary sketch to illustrate my staging yard. (remember, there are two such, very similar).
You can see, I hope , how it makes sense to me to simply reverse the entire B/C loop section, and thereby avoid other complications.? I looked at using an AR for each approach, e.g. L to N, or even just M to N, and similarly Q or R to S; in each case, there are use cases where the reversing block thus created could have a train entering and leaving.? Only the crossover bottleneck presents a single, unambiguous reverse vs don't-reverse use case.
I think, on the whole, reversing the booster would be best, if only the booster fed only sections B and C.? However, given that I still have hopes of initially running both staging areas from one booster, as shown, that option is off the table, leaving me with only one - reverse using a DPDT relay dedicated to each staging yard, as shown.? I don't want to use an AR here, as an AR will be used for track section D, and it will be connected to B, forming the dreaded "adjacent AR" conundrum.
Blair
|
Re: Block Detection for signalling and automation
Hi Tim
That's more along the lines of what I was looking for in an answer, thanks.
I was already planning on dealing with industry, interchange, and house tracks that way.? As for turnouts for automation, it's a good point - but really, the automation should be looking at least 1-2 blocks ahead of the train and aligning turnouts appropriately, unless there are extenuating circumstances.? If a turnout is in a block, it shouldn't need to be thrown once occupied.
Looks like someone's going to have to push some more $$$ in to the detection budget.? Ouch!? I think I'm heading for somewhere around 100 blocks; between the detection, and the reporting equipment, and JMRI, I'll be busy for a while.? Good thing it's a hobby!? I think I'll gap it all for future detection, even if I then incorporate multiple sections into one block initially. Easier to separate out and detect separately if needed.
Thanks again
Blair
|
Re: Block Detection for signalling and automation
Hi Blair;
It depends (don't you love that answer?)?
Turnouts for industry spurs and other similar connections to "track other than main track" do not need to be individually detected. The tracks they lead to should be gapped and not detected. You don't want a boxcar at the Joe's Widget Factory loading dock to trip the detector.?
Given that, it is good practice to make turnouts lined away from the main track force the block to show occupied. I do this by placing a 10k ohm resistor between the frog and the diverging stock rail.?
As far as turnouts at the ends of passing sidings, or at the end of double track, or crossovers between multiple track, it depends. For the signaling on my layout (ABS/APB) turnouts are part of the block they are adjacent to, depending on signal configuration at that location. For CTC, these turnouts are isolated. It seems like a good to isolate turnouts for automation so that you can prevent throwing them while occupied.
Tim Rumph
Lancaster, SC
|
Re: DCC Bus reversing question
Thanks for the generic DCC reversing how to, Jim; I'm sure it is
well intentioned.? Doesn't address my question exactly, but others
will benefit.
I have to reverse a large area of my layout(up to 16 trains);
that area is driven by it's own booster, BUT I want multiple
sub-sections protected by SS breakers.? Though each track of my
staging can be shut off, the upshot is I could have up to 4
multi-unit trains running simultaneously in the yard and
approaches.? I want those trains to proceed without a glitch when
I change the alignment of the |X|, so the reversing needs to be
solid state.? I also want the yard and the approach tracks on
separate circuit breakers.? So I see my booster either reversing
and feeding breakers, or feeding an autoreverser* which then feeds
two or more breakers.?
Your description of your layout is similar, though smaller I
expect, than my situation.
The autoreverser must be FASTER than the circuit breakers in
order to reverse before they act, else it won't act.? If the short
is sustained (i.e. not resolved by the AR), then I want the
circuit breakers to act BEFORE the AR swaps the polarity again; I
strongly suspect the AR actions will suppress the sensing of a
short by the breakers, resetting their timing.? So I don't think
this will work well - I expect it will flip-flip-flip ad nauseum.?
Alternatives:
- Reverse the Loconet Railsync signals, which you don't seem to
like, but which I see no fundamental issue with, or
- use an autoreverser that can be triggered externally by the
same signal driving the tortoises on the |X|.? I can't quite see
how to do this using the PSX-AR, but I may just have misread the
manual.? Comments appreciated if someone has done this.
I'm presently reviewing my staging plan to see if I can identify
a single stretch of track in each approach that could be
considered a "reversing section" of it's own, thus allowing the
staging yard itself to be fixed polarity.? Problem is, if I do
that, I think I can still have multiple trains entering/leaving it
simultaneously, due to the layout, which wouldn't be acceptable.?
These concerns are what resulted in my "flip-it-all based on one
crossover state" approach.
Blair
On 2021-08-08 20:39, Jim Betz wrote:
toggle quoted message
Show quoted text
Blair/Don ... and all,
? You don't need to re-invent the wheel.? DCC works just fine as
designed.? DCC wiring - if
you follow Gartner's recommendations - is also easy and fool proof
(if you follow them
correctly).? Specific responses:
? 1) No you don't need to swap railsync wires - and you shouldn't
do so.
? 2) Yes, you can use some kind of physical switch to "rewire"
reversing
? ? ? ?sections.? Most guys like the automated aspect of a
Reversing DCC
? ? ? ?circuit breaker.
? 3) The best (in my opinion) DCC circuit breakers are the PSX
series.? They
? ? ? ?work and work well.? They were designed with sound in
mind.? They are
? ? ? ?electronic (which makes them fast).? Yes, they cost a bit
more than?
? ? ? ?other brands of DCC circuit breaker - yes, they are worth
it.
? 4) A reversing section should not be up against another
reversing section if
? ? ? you are using DCC circuit breakers.? They end up trying to
out guess each
? ? ? other - and that competition usually goes on forever.? You
can, with some
? ? ? breakers, set a different trip speed to prevent this ... but
it is better to not
? ? ? have two reversing sections next to each other.? This is
almost always
? ? ? possible thru careful selection of where your breaker
boundaries are.
? 5) A reversing section should be "longer than the longest train
you will
? ? ? ever run thru it".? It does not have to be "the entire loop"
- but most guys
? ? ? will set it up that way and it's usually easier.? Another
way to say this one
? ? ? is "you don't want both ends of the train - or two trains at
once - crossing
? ? ? the reversing section".? Again, the breaker gets confused
and, in this case,
? ? ? ends up competing with itself.
? Reversing breakers work like this:
? a) Situation normal.
? b) A short occurs.
? c) The breaker -temporarily- tries reversing the polarity of the
reversing
? ? ? section.
? d) If that works it leaves it alone and the train continues to
run.
? e) If it didn't work then you have an "actual short" and the
breaker goes
? ? ? into "there's a short" status.
? f) Most modern DCC circuit breakers also have an automated
Retry.
? ? ?They will wait a second or two and then retest to see if the
short is
? ? ?still there - this is what allows you to throw the switch and
"clear the
? ? ?short".
? On my layout I have just one reversing section - it is the huge
loop in
staging - the staging is 5 tracks wide and 3 trains long.? All
trains enter
(and exit) staging thru just one track that goes to a switch.? All
of the
track past that switch is both Staging and the reversing loop.? I
have it
wired with just one circuit breaker.? If it ends up that there are
too many
trains in staging (amp draw too high) I will cut the power to some
of the
tracks (the ones that the turnouts make "unavailable".
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? - Jim
??
|
Block Detection for signalling and automation
Hi Folks
When blocking a section of track for signalling and automation, is it necessary to isolate and detect each turnout, or can the turnout be part of the approach block?? I can see how it might be 'better' to detect the turnout, but does it actually matter when it comes down to it?? I'm thinking the answer is 'isolate them for signalling, but don't bother for automation', but I'd like confirmation.? If I don't need separate detection in staging, it saves me a significant number of detection circuits.
Thanks
Blair Smith
|
I use it regularly on the surface mount style LEDs. Craig Zeni
Cary, NC
Despatched from my infernal Android
I just wondered why I don't see/hear questions about using magnet wire.? Are there reasons to avoid such wire or is it a matter of convenience in handling or some other factors??
|
Swanny
Jim Betz
Tim
Craig Zeni