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J. B. Wood
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 Posted: Fri Aug 22, 2008 4:05 pm Post subject: Reverse Loop Implementation |
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Hello, fellow railroaders. I feel silly asking this as I am an EE by
profession but can anyone with access to a 1950s era American Flyer
s-gauge instruction manual explain why the hookup for a single
reverse-loop using a manual DPDT switch (not a reverse loop relay)
apparently has to be more complicated than required? In addition to a
track switch (turnout) it requires six track insulating pins and
presumably three track terminals. I understand how it operates in this
manner but, in addition to a DPDT switch, why not just make use of the
two-train option on the turnout and a single insulated track section?
Thanks for your time and comment. Sincerely,
John Wood (Code 5550) e-mail: wood@itd.nrl.navy.mil
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337 |
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Bill
Guest
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| Posted: Fri Aug 22, 2008 4:05 pm Post subject: Re: Reverse Loop Implementation |
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On Aug 22, 7:05 am, w...@itd.nrl.navy.mil (J. B. Wood) wrote:
| Quote: | Hello, fellow railroaders. I feel silly asking this as I am an EE by
profession but can anyone with access to a 1950s era American Flyer
s-gauge instruction manual explain why the hookup for a single
reverse-loop using a manual DPDT switch (not a reverse loop relay)
apparently has to be more complicated than required? In addition to a
track switch (turnout) it requires six track insulating pins and
presumably three track terminals. I understand how it operates in this
manner but, in addition to a DPDT switch, why not just make use of the
two-train option on the turnout and a single insulated track section?
Thanks for your time and comment. Sincerely,
John Wood (Code 5550) e-mail: w...@itd.nrl.navy.mil
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337
|
-----------------------------------------------------------------------------------------------------------
Perhaps you can find some information here...
http://www.rfgco.com/
Bill
Bill's Railroad Empire
N Scale Model Railroad:
http://www.billsrailroad.net
Brief History of N Scale:
http://www.billsrailroad.net/history/n-scale
Bill's Store--Books, Trains, and Toys:
http://www.billsrailroad.net/bookstore
Resources--Links to 1,200 sites:
http://www.billsrailroad.net/bills-favorite-links |
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Wolf Kirchmeir
Guest
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| Posted: Sun Aug 24, 2008 11:07 pm Post subject: Re: Reverse Loop Implementation |
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J. B. Wood wrote:
| Quote: | Hello, fellow railroaders. I feel silly asking this as I am an EE by
profession but can anyone with access to a 1950s era American Flyer
s-gauge instruction manual explain why the hookup for a single
reverse-loop using a manual DPDT switch (not a reverse loop relay)
apparently has to be more complicated than required? In addition to a
track switch (turnout) it requires six track insulating pins and
presumably three track terminals. I understand how it operates in this
manner but, in addition to a DPDT switch, why not just make use of the
two-train option on the turnout and a single insulated track section?
Thanks for your time and comment. Sincerely,
John Wood (Code 5550) e-mail: wood@itd.nrl.navy.mil
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337
|
That AF manual presumably applies to 2-rail track. For such track, you
need only one additonal DPDT switch, and four insulating track pins.
I haven't seen the AF manual you refer to, so I don't understand how the
reversing loops would need six insulating pins, etc. I suspect the
designers thought they had to insulate the turnout as well, but I don't
see why they would want to do that.
As you know, you need no special wiring for a reverse loop with 3-rail
track.
--
wolf k. |
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Robert Heller
Guest
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| Posted: Mon Aug 25, 2008 12:44 am Post subject: Re: Reverse Loop Implementation |
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At Sun, 24 Aug 2008 14:07:06 -0400 Wolf Kirchmeir <wolfkir@sympatico.ca> wrote:
| Quote: |
J. B. Wood wrote:
Hello, fellow railroaders. I feel silly asking this as I am an EE by
profession but can anyone with access to a 1950s era American Flyer
s-gauge instruction manual explain why the hookup for a single
reverse-loop using a manual DPDT switch (not a reverse loop relay)
apparently has to be more complicated than required? In addition to a
track switch (turnout) it requires six track insulating pins and
presumably three track terminals. I understand how it operates in this
manner but, in addition to a DPDT switch, why not just make use of the
two-train option on the turnout and a single insulated track section?
Thanks for your time and comment. Sincerely,
John Wood (Code 5550) e-mail: wood@itd.nrl.navy.mil
Naval Research Laboratory
4555 Overlook Avenue, SW
Washington, DC 20375-5337
That AF manual presumably applies to 2-rail track. For such track, you
need only one additonal DPDT switch, and four insulating track pins.
I haven't seen the AF manual you refer to, so I don't understand how the
reversing loops would need six insulating pins, etc. I suspect the
designers thought they had to insulate the turnout as well, but I don't
see why they would want to do that.
|
It might depend on where the power pack was connected. If the power
pack feed was wired to someplace on the reverse loop itself, then yes,
you would need to isolate the turnout. Of course, running a power pack
feed to the trackage of a reverse loop, is itself wrong, since the
rule-of-thumb is to always power turnout rails from the point end and
NOT from either of the frog ends.
| Quote: |
As you know, you need no special wiring for a reverse loop with 3-rail
track.
|
Nor with an overhead powered trolley.
Note: a two-rail reverse loop shares some 'features' as a mobious strip.
This might be a good way to visualize the issues of two-rail reverse loops.
--
Robert Heller -- 978-544-6933
Deepwoods Software -- Download the Model Railroad System
http://www.deepsoft.com/ -- Binaries for Linux and MS-Windows
heller@deepsoft.com -- http://www.deepsoft.com/ModelRailroadSystem/ |
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J.B. Wood
Guest
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| Posted: Mon Aug 25, 2008 6:06 pm Post subject: Re: Reverse Loop Implementation |
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Wolf Kirchmeir wrote:
| Quote: | That AF manual presumably applies to 2-rail track. For such track, you
need only one additonal DPDT switch, and four insulating track pins.
I haven't seen the AF manual you refer to, so I don't understand how the
reversing loops would need six insulating pins, etc. I suspect the
designers thought they had to insulate the turnout as well, but I don't
see why they would want to do that.
As you know, you need no special wiring for a reverse loop with 3-rail
track.
|
Hello, Wolf, and all. First, my thanks for all the replies. After
additional study of the s-gauge American Flyer (AF) track switches
(turnouts) I've concluded that the intent of the AF single reverse loop
wiring is to 1) not interrupt the current to the running train while in
the loop as the DPDT switch is thrown (this is stated in the AF manual)
and 2) by setting the "2-train" button on the turnout appropriately,
cause the train to stop in the loop short of the turnout to prevent
derailment. This would be the case when, after throwing the DPDT
switch, the operator forgets or is late in switching the turnout to the
position required for train exit from the loop.
It's interesting to note that when wiring up the AF reverse loop relay
per AF instructions to somewhat automate the reverse loop (you still
have to manually throw the turnout) the current to the train in the loop
will be momentarily interrupted. In this case, however, only one
insulated block section vice three (using the DPDT switch method) is
needed. Sincerely, |
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mark
Guest
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| Posted: Tue Aug 26, 2008 6:06 am Post subject: Re: Reverse Loop Implementation |
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John,
J. B. Wood wrote:
| Quote: | Hello, fellow railroaders. I feel silly asking this as I am an EE by
profession but can anyone with access to a 1950s era American Flyer
snip |
Well, if you're an EE, let me lean on *you*: I've been on and off looking
around for a simple white noise circuit.
Why? Because I took the $20 sound car apart, and the circuit looks more
complicated than it needs to be, and I'd like a schematic so I can just
build half a dozen (hopefully for less than $20/pop to put in my tenders
behind my steam engines, of course.
mark "painting and making a brush for the axle's the easy part" |
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David Nebenzahl
Guest
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| Posted: Tue Aug 26, 2008 7:13 am Post subject: Re: Reverse Loop Implementation |
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On 8/25/2008 6:06 PM mark spake thus:
| Quote: | J. B. Wood wrote:
Hello, fellow railroaders. I feel silly asking this as I am an EE by
profession but can anyone with access to a 1950s era American Flyer
snip
Well, if you're an EE, let me lean on *you*: I've been on and off looking
around for a simple white noise circuit.
Why? Because I took the $20 sound car apart, and the circuit looks more
complicated than it needs to be, and I'd like a schematic so I can just
build half a dozen (hopefully for less than $20/pop to put in my tenders
behind my steam engines, of course.
|
Ackshooly, you ought to be able to find lots of those out there in
web-land. I say that because a couple years I got a wild straw up my
butt to build a circuit to simulate a flickering fire, based on a noise
generator. It never worked you (well, at least not yet), but I did find
lots of noise-generating circuits along the way. May even still have
some links.
Hint: there are basically two types of noise generators: simple and
complicated. The simple ones are "analog" and usually use a
reverse-biased transistor as an avalanche diode (only two connections
used). The complicated ones use all kinds of logic components to
generate what is usually a pseudo-random repeating sequence. I favor the
simple ones myself. Basically all you need besides the generator is a
filter to select the frequency range you want (a capacitor or three) and
a small amplifier (one chip, like a 741).
--
"In 1964 Barry Goldwater declared: 'Elect me president, and I
will bomb the cities of Vietnam, defoliate the jungles, herd the
population into concentration camps and turn the country into a
wasteland.' But Lyndon Johnson said: 'No! No! No! Don't you dare do
that. Let ME do it.'"
- Characterization (paraphrased) of the 1964 Goldwater/Johnson
presidential race by Professor Irwin Corey, "The World's Foremost
Authority". |
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mark
Guest
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| Posted: Wed Aug 27, 2008 6:29 am Post subject: Re: Reverse Loop Implementation |
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David Nebenzahl wrote:
| Quote: | On 8/25/2008 6:06 PM mark spake thus:
J. B. Wood wrote:
Hello, fellow railroaders. I feel silly asking this as I am an EE by
profession but can anyone with access to a 1950s era American Flyer
snip
Well, if you're an EE, let me lean on *you*: I've been on and off looking
around for a simple white noise circuit.
Why? Because I took the $20 sound car apart, and the circuit looks more
complicated than it needs to be, and I'd like a schematic so I can just
build half a dozen (hopefully for less than $20/pop to put in my tenders
behind my steam engines, of course.
Ackshooly, you ought to be able to find lots of those out there in
web-land. I say that because a couple years I got a wild straw up my
butt to build a circuit to simulate a flickering fire, based on a noise
generator. It never worked you (well, at least not yet), but I did find
lots of noise-generating circuits along the way. May even still have
some links.
Hint: there are basically two types of noise generators: simple and
complicated. The simple ones are "analog" and usually use a
reverse-biased transistor as an avalanche diode (only two connections
used). The complicated ones use all kinds of logic components to
generate what is usually a pseudo-random repeating sequence. I favor the
simple ones myself. Basically all you need besides the generator is a
filter to select the frequency range you want (a capacitor or three) and
a small amplifier (one chip, like a 741).
|
All the ones I found seemed to be digital, and went on about white and pink
noise generators. Got any links, or even an ASCII-art circuit diagram?
mark |
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David Nebenzahl
Guest
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| Posted: Wed Aug 27, 2008 6:43 am Post subject: Re: Reverse Loop Implementation |
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On 8/26/2008 6:29 PM mark spake thus:
| Quote: | David Nebenzahl wrote, going on and on about something:
..
Ackshooly, you ought to be able to find lots of those out there in
web-land. I say that because a couple years I got a wild straw up my
butt to build a circuit to simulate a flickering fire, based on a noise
generator. It never worked you (well, at least not yet), but I did find
lots of noise-generating circuits along the way. May even still have
some links.
Hint: there are basically two types of noise generators: simple and
complicated. The simple ones are "analog" and usually use a
reverse-biased transistor as an avalanche diode (only two connections
used). The complicated ones use all kinds of logic components to
generate what is usually a pseudo-random repeating sequence. I favor the
simple ones myself. Basically all you need besides the generator is a
filter to select the frequency range you want (a capacitor or three) and
a small amplifier (one chip, like a 741).
All the ones I found seemed to be digital, and went on about white and pink
noise generators. Got any links, or even an ASCII-art circuit diagram?
|
Most of my links seem to have evaporated somehow. I did find this one:
http://www.musicfromouterspace.com/analogsynth/rayspinknoise.html
Here, Q1 is used as a the noise source as I described; notice how the
collector is clipped off. The rest of it is just a filter network and
amplifier.
--
"In 1964 Barry Goldwater declared: 'Elect me president, and I
will bomb the cities of Vietnam, defoliate the jungles, herd the
population into concentration camps and turn the country into a
wasteland.' But Lyndon Johnson said: 'No! No! No! Don't you dare do
that. Let ME do it.'"
- Characterization (paraphrased) of the 1964 Goldwater/Johnson
presidential race by Professor Irwin Corey, "The World's Foremost
Authority". |
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| Back to top |
mark
Guest
|
| Posted: Fri Aug 29, 2008 5:44 am Post subject: Re: Reverse Loop Implementation |
|
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David Nebenzahl wrote:
| Quote: | On 8/26/2008 6:29 PM mark spake thus:
David Nebenzahl wrote, going on and on about something:
.
Ackshooly, you ought to be able to find lots of those out there in
web-land. I say that because a couple years I got a wild straw up my
butt to build a circuit to simulate a flickering fire, based on a noise
generator. It never worked you (well, at least not yet), but I did find
lots of noise-generating circuits along the way. May even still have
some links.
Hint: there are basically two types of noise generators: simple and
complicated. The simple ones are "analog" and usually use a
reverse-biased transistor as an avalanche diode (only two connections
used). The complicated ones use all kinds of logic components to
generate what is usually a pseudo-random repeating sequence. I favor the
simple ones myself. Basically all you need besides the generator is a
filter to select the frequency range you want (a capacitor or three) and
a small amplifier (one chip, like a 741).
All the ones I found seemed to be digital, and went on about white and
pink noise generators. Got any links, or even an ASCII-art circuit
diagram?
Most of my links seem to have evaporated somehow. I did find this one:
http://www.musicfromouterspace.com/analogsynth/rayspinknoise.html
Here, Q1 is used as a the noise source as I described; notice how the
collector is clipped off. The rest of it is just a filter network and
amplifier.
|
Ok, I've never studied electronics - the times I've built anything, it's
follow the directions. I still don't know why I would prefer pink to white
noise for a chuff-chuff. Also, the link you sent left me somewhat
confused - it looked like two separate circuits.
Any thoughts on this link? <http://www.ciphersbyritter.com/NOISE/NOISRC.HTM.
mark |
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David Nebenzahl
Guest
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| Posted: Fri Aug 29, 2008 7:13 am Post subject: Re: Reverse Loop Implementation |
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On 8/28/2008 5:44 PM mark spake thus:
| Quote: | David Nebenzahl wrote:
On 8/26/2008 6:29 PM mark spake thus:
David Nebenzahl wrote, going on and on about something:
.
Ackshooly, you ought to be able to find lots of those out there in
web-land. I say that because a couple years I got a wild straw up my
butt to build a circuit to simulate a flickering fire, based on a noise
generator. It never worked you (well, at least not yet), but I did find
lots of noise-generating circuits along the way. May even still have
some links.
Hint: there are basically two types of noise generators: simple and
complicated. The simple ones are "analog" and usually use a
reverse-biased transistor as an avalanche diode (only two connections
used). The complicated ones use all kinds of logic components to
generate what is usually a pseudo-random repeating sequence. I favor the
simple ones myself. Basically all you need besides the generator is a
filter to select the frequency range you want (a capacitor or three) and
a small amplifier (one chip, like a 741).
All the ones I found seemed to be digital, and went on about white and
pink noise generators. Got any links, or even an ASCII-art circuit
diagram?
Most of my links seem to have evaporated somehow. I did find this one:
http://www.musicfromouterspace.com/analogsynth/rayspinknoise.html
Here, Q1 is used as a the noise source as I described; notice how the
collector is clipped off. The rest of it is just a filter network and
amplifier.
Ok, I've never studied electronics - the times I've built anything, it's
follow the directions. I still don't know why I would prefer pink to white
noise for a chuff-chuff. Also, the link you sent left me somewhat
confused - it looked like two separate circuits.
Any thoughts on this link? <http://www.ciphersbyritter.com/NOISE/NOISRC.HTM.
|
That's basically the same thing, but a lot simpler. Heck, build it and
try it out. Parts can't cost more than $5-8.
That one, by the way, works the same way, by reverse-biasing a
semiconductor (here a zener diode instead of a transistor). What
happens, to oversimplify a bit, is that the junction "breaks down" in a
very jagged way (if one graphs it), producing a lot of noise.
--
"In 1964 Barry Goldwater declared: 'Elect me president, and I
will bomb the cities of Vietnam, defoliate the jungles, herd the
population into concentration camps and turn the country into a
wasteland.' But Lyndon Johnson said: 'No! No! No! Don't you dare do
that. Let ME do it.'"
- Characterization (paraphrased) of the 1964 Goldwater/Johnson
presidential race by Professor Irwin Corey, "The World's Foremost
Authority". |
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| Back to top |
Wolf Kirchmeir
Guest
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| Posted: Fri Aug 29, 2008 7:13 am Post subject: Re: Reverse Loop Implementation |
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mark wrote:
[...]
| Quote: | Ok, I've never studied electronics - the times I've built anything, it's
follow the directions. I still don't know why I would prefer pink to white
noise for a chuff-chuff. [...]
|
"White noise" is a mix of pretty well the full range of audible
frequencies. It so happens that the sound of steam escaping from a small
chamber and expanding into the atmosphere is pretty close to white
noise. Boost the bass a bit, and you have the snd of a larger engine. Etc.
HTH
--
wolf k. |
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mark
Guest
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| Posted: Sat Aug 30, 2008 7:16 am Post subject: Re: Reverse Loop Implementation |
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David Nebenzahl wrote:
| Quote: | On 8/28/2008 5:44 PM mark spake thus:
David Nebenzahl wrote:
On 8/26/2008 6:29 PM mark spake thus:
David Nebenzahl wrote, going on and on about something:
.
Ackshooly, you ought to be able to find lots of those out there in
web-land. I say that because a couple years I got a wild straw up my
butt to build a circuit to simulate a flickering fire, based on a
noise generator. It never worked you (well, at least not yet), but I
did find lots of noise-generating circuits along the way. May even
still have some links.
Hint: there are basically two types of noise generators: simple and
complicated. The simple ones are "analog" and usually use a
reverse-biased transistor as an avalanche diode (only two connections
used). The complicated ones use all kinds of logic components to
generate what is usually a pseudo-random repeating sequence. I favor
the simple ones myself. Basically all you need besides the generator
is a filter to select the frequency range you want (a capacitor or
three) and a small amplifier (one chip, like a 741).
All the ones I found seemed to be digital, and went on about white and
pink noise generators. Got any links, or even an ASCII-art circuit
diagram?
Most of my links seem to have evaporated somehow. I did find this one:
http://www.musicfromouterspace.com/analogsynth/rayspinknoise.html
Here, Q1 is used as a the noise source as I described; notice how the
collector is clipped off. The rest of it is just a filter network and
amplifier.
Ok, I've never studied electronics - the times I've built anything, it's
follow the directions. I still don't know why I would prefer pink to
white noise for a chuff-chuff. Also, the link you sent left me somewhat
confused - it looked like two separate circuits.
Any thoughts on this link?
http://www.ciphersbyritter.com/NOISE/NOISRC.HTM.
That's basically the same thing, but a lot simpler. Heck, build it and
try it out. Parts can't cost more than $5-8.
That one, by the way, works the same way, by reverse-biasing a
semiconductor (here a zener diode instead of a transistor). What
happens, to oversimplify a bit, is that the junction "breaks down" in a
very jagged way (if one graphs it), producing a lot of noise.
Thanks, that's muchly appreciated. And if I buy a package of the parts, I'll |
have what I was looking for. Now if I could only find my round tuit.....
mark |
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Twibil
Guest
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| Posted: Sun Aug 31, 2008 12:56 am Post subject: Re: Reverse Loop Implementation |
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On Aug 30, 5:00 pm, "Greg.Procter" <proc...@ihug.co.nz> wrote:
| Quote: | A 1.5 volt GOW bulb replacing the speaker on an old but working transistor
radio will give a visually random output, depending on the type of radio
station you tune into.
|
Every Grain-Of-Wheat (GOW) bulb I've ever seen has been rated at 12-14
volts. Grain-Of-Rice (GOR) bulbs, on the other hand, are 1.5 volters.
Unless they've changed the terminology and I just didn't notice?
-Pete |
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Greg.Procter
Guest
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| Posted: Sun Aug 31, 2008 5:00 am Post subject: Re: Reverse Loop Implementation |
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On Tue, 26 Aug 2008 17:17:43 +1200, David Nebenzahl
<nobody@but.us.chickens> wrote:
| Quote: | On 8/25/2008 6:06 PM mark spake thus:
J. B. Wood wrote:
Hello, fellow railroaders. I feel silly asking this as I am an EE by
profession but can anyone with access to a 1950s era American Flyer
snip
Well, if you're an EE, let me lean on *you*: I've been on and off
looking
around for a simple white noise circuit. Why? Because I took the $20
sound car apart, and the circuit looks more
complicated than it needs to be, and I'd like a schematic so I can just
build half a dozen (hopefully for less than $20/pop to put in my tenders
behind my steam engines, of course.
Ackshooly, you ought to be able to find lots of those out there in
web-land. I say that because a couple years I got a wild straw up my
butt to build a circuit to simulate a flickering fire, based on a noise
generator. It never worked you (well, at least not yet), but I did find
lots of noise-generating circuits along the way. May even still have
some links.
Hint: there are basically two types of noise generators: simple and
complicated. The simple ones are "analog" and usually use a
reverse-biased transistor as an avalanche diode (only two connections
used). The complicated ones use all kinds of logic components to
generate what is usually a pseudo-random repeating sequence. I favor the
simple ones myself. Basically all you need besides the generator is a
filter to select the frequency range you want (a capacitor or three) and
a small amplifier (one chip, like a 741).
|
A 1.5 volt GOW bulb replacing the speaker on an old but working transistor
radio will give a visually random output, depending on the type of radio
station you tune into.
(Hip-hop actually has a use!)
(Wagner requires the volume to be turned down)
Greg.P. |
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