Re: Diode Lighting circuit
To get a bit technical, the motor is acting as ballast (electrical ballast) for the diode circuit. This prevents excessive current through the diodes.
If you connected the diode circuit directly across power from the rails, they will be destroyed - and very quickly with a lot of heat and maybe even a small "explosion."
The diodes are acting as a low budget voltage regulator.? At a very low current, each diode (that is forward biased) will drop around 0.6 volts.? As current increases, that voltage remains almost the same.? But there MUST be something for any voltage above that point to be dropped across.? That is the motor.
Remember, the goal is for constant lighting with any track voltage.? With the motor as "ballast", from the point of view of the diode circuit, excess voltage is dropped across the motor, not the diode circuit.? Of course, this "excess voltage" is what will make the motor turn which is a big plus for a model railroad engine.? But the diode circuit doesn't know that.? You could replace the motor with a resistor and the diode circuit would be just as happy.
Charles E. "Chuck" Kinzer
On Thursday, December 19, 2024 at 01:31:35 PM PST, Ben via groups.io <pickycat95@...> wrote:
Why is the lighting circuit wired in series in the motor circuit and not a parallel lighting circuit?
Ben Trousdale
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Re: Diode Lighting circuit
On Thu, Dec 19, 2024 at 11:43 AM, Mike Swederska wrote:
don¡¯t hook it to your motor in my opinion that¡¯s incorrect because it does affect the Motors RPM ?output.
Mike Swederska?
I am taking an uneducated guess here, but it looks to me like the circuit enables the lights to illuminate BEFORE the motor starts to rotate.? Thus, the lights could be on while the train is waiting at the station.? Or something like that.? Just a guesstimate, but what the heck..........it might be correct.? Ed L.
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Ed Loizeaux
Los Altos, CA
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Re: Diode Lighting circuit
Why is the lighting circuit wired in series in the motor circuit and not a parallel lighting circuit?
Ben Trousdale
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Re: Diode Lighting circuit
I'm not sure I understand the question about the four diodes.? But you can put as many diodes in series as you want.? Each one adds about another 0.6 volts of voltage drop.? Each series diode increase the voltage needed to start the motor, and the maximum voltage available to the motor (and therefore speed).? Of course, everything here is, I assume, for a DC operated locomotive.? No DCC.
More diodes DOES make it easier to apply a small voltage to get a light to turn on but not make the motor run.? So, you can have a light on when stopped.? This works well with permanent magnet motors.? With lower current can motors which move more easily, it may be difficult to get a lamp bulb to light without also having the motor run.
There is some interesting history behind these schemes.? One early scheme (perhaps the first published) was in the December 1962 issue of model railroader.? ("Simple Way to Keep Headlights Burning" by G. R> Stilwell).? It used a seven diode scheme.? I was 15 years old at the time and didn't see the need for seven and did the same six diode scheme you have.? Which I believe became much more common.? However, the article was very focused on pricing (diodes not being as dirt cheap as they are today) and with the seven diode scheme two could be low current and much less costly.? This may have been the reason.
What's going on here is that with either polarity, 3 of the diodes of the 5 in the center are forward biased giving three voltage drops.? D1 and D2 have the purpose of cancelling out a voltage drop leaving a 2 diode drop and adding the directionality.
But somebody came along with a nice little twist to this circuit that makes the headlight dim in reverse, not off.? This is more prototypical.
From the May 1987 Model Railroader magazine "Symposium on Electronics" column.
It is the arrangement of the diodes that causes the headlight to dim in reverse.? The resistor limits the current to both bulbs for the purpose of giving them a better "hue" according to the text.? And, yes, it can make your eyes bleed a bit to trace currents through this little circuit if you aren't used to reading such things.? And sometimes even if you are.? (I know it is drawn better in another issue, but I couldn't find it.)
Charles E. "Chuck" Kinzer
On Thursday, December 19, 2024 at 10:44:04 AM PST, ken garber via groups.io <garber.ken@...> wrote:
Theoretically speaking.... if you put four diodes in each branch...? albeit at a loss of loco speed.??
Ken g
I was working on an answer and this got pretty well answered before I could post.
Anyway, the voltage drop will be closer to 1.2 volts (approximately 0.6 volts per diode).? It is intended to be used with 1.5 volt incandescent bulbs.? The slightly lowered voltage has the benefit of substantially extending the bulb life.
This is not for use with LEDs.? They have about a 2.4 volt forward voltage drop so I would expect them to remain dark at all times.? ?Also, LEDs require current limiting (usually just a resistor) appropriate for whatever is a high enough voltage to get them to work.
Here is a schematic showing the network in series with the motor.? But it doesn't really add anything beyond the labeled photo already provided.
![Inline image]( "Inline image") Charles E. "Chuck" Kinzer
On Thursday, December 19, 2024 at 08:58:05 AM PST, ken garber via <garber.ken= [email protected]> wrote:
This circuit goes "in series" with one of the leads coming from the track to the motor.
For lighting, the common connection for the two lights is the junction at the right.
Each lamp/LED will be attached to the short 'terminals' left of center.
This will result in a lamp wired across two rectifiers, resulting in an approximate?1.5 volt drop.
Then you just determine?which lamp lights when running in what direction.
Ken G.
I'm sure I've asked this before--and kind souls have answered it¡ªbut I am finally ready to put my Alco RSD-4/5 back together and (electronic ignoramus that I am) I don't know where to connect the leads from the motor nor the leads from the headlights and can't
find the answers previously provided.
I assume this is a constant lighting circuit, likely also with directional lighting.
My expertise usually extends only to using pre-wired LED's.
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Re: Diode Lighting circuit
Hi Jace, you didn¡¯t state whether you were running straight DC or if you were running DCC with a decoder. I¡¯m assuming you¡¯re gonna be running straight DC and no decoder so on average 12 to 13 V on the rails at full throttle.
With that said LEDs only allow electricity to flow through them in one direction giving directional lighting.
I stock 1000 ohm 2000 ohm and 3000 ohm resistors for my LEDs to determine how bright I want them to be. You can wire the LED straight to your rails with one of those resistors. By determining when you throw the track direction which is the polarity on DC if the LED is going to light or not light. Wire the other opposite of the first. Your done. ?You don¡¯t hook it to your motor in my opinion that¡¯s incorrect because it does affect the Motors RPM ?output. Mike Swederska?
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On Dec 19, 2024, at 10:49?AM, JGG KahnSr via groups.io <jacekahn@...> wrote:
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I'm sure I've asked this before--and kind souls have answered it¡ªbut I am finally ready to put my Alco RSD-4/5 back together and (electronic ignoramus that I am) I don't know where to connect the leads from the motor nor the leads from the headlights and can't
find the answers previously provided.
I assume this is a constant lighting circuit, likely also with directional lighting.
My expertise usually extends only to using pre-wired LED's.
<Diode lighting circuit.jpg>
--
Mike Swederska
Meramec Valley Lines
Modeling Mopac equipment in 3/16
Don't let perfection get in the way of good enough! Keep model railroading fun!
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Re: S Helper 2-8-0 Consolidated DCC
No poly hose in SHS 2-8-0¡.
Don
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Re: Diode Lighting circuit
Theoretically speaking.... if you put four diodes in each branch...? albeit at a loss of loco speed.??
Ken g
I was working on an answer and this got pretty well answered before I could post.
Anyway, the voltage drop will be closer to 1.2 volts (approximately 0.6 volts per diode).? It is intended to be used with 1.5 volt incandescent bulbs.? The slightly lowered voltage has the benefit of substantially extending the bulb life.
This is not for use with LEDs.? They have about a 2.4 volt forward voltage drop so I would expect them to remain dark at all times.? ?Also, LEDs require current limiting (usually just a resistor) appropriate for whatever is a high enough voltage to get them to work.
Here is a schematic showing the network in series with the motor.? But it doesn't really add anything beyond the labeled photo already provided.
Charles E. "Chuck" Kinzer
On Thursday, December 19, 2024 at 08:58:05 AM PST, ken garber via <garber.ken= [email protected]> wrote:
This circuit goes "in series" with one of the leads coming from the track to the motor.
For lighting, the common connection for the two lights is the junction at the right.
Each lamp/LED will be attached to the short 'terminals' left of center.
This will result in a lamp wired across two rectifiers, resulting in an approximate?1.5 volt drop.
Then you just determine?which lamp lights when running in what direction.
Ken G.
I'm sure I've asked this before--and kind souls have answered it¡ªbut I am finally ready to put my Alco RSD-4/5 back together and (electronic ignoramus that I am) I don't know where to connect the leads from the motor nor the leads from the headlights and can't
find the answers previously provided.
I assume this is a constant lighting circuit, likely also with directional lighting.
My expertise usually extends only to using pre-wired LED's.
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SwitchMaster turnout motors
Gents........
I have 90 of these motors for sale at a 50% discount from the current retail price.? ?Write me for details.??
I'd like to smile if these can find a new good home.? O scale guys really like them.? If you have an O scale buddy, please let him know.? Maybe G scale or #1 scale fellas also.
Email preferred.? Phone works.? ? Loizeaux aht SBC // Global daht? net? ? ? 1-650-962-1577
"S"incerely..........Ed Loizeaux -- Ed Loizeaux Los Altos, CA
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Re: Diode Lighting circuit
I was working on an answer and this got pretty well answered before I could post.
Anyway, the voltage drop will be closer to 1.2 volts (approximately 0.6 volts per diode).? It is intended to be used with 1.5 volt incandescent bulbs.? The slightly lowered voltage has the benefit of substantially extending the bulb life.
This is not for use with LEDs.? They have about a 2.4 volt forward voltage drop so I would expect them to remain dark at all times.? ?Also, LEDs require current limiting (usually just a resistor) appropriate for whatever is a high enough voltage to get them to work.
Here is a schematic showing the network in series with the motor.? But it doesn't really add anything beyond the labeled photo already provided.
 Charles E. "Chuck" Kinzer
On Thursday, December 19, 2024 at 08:58:05 AM PST, ken garber via groups.io <garber.ken@...> wrote:
This circuit goes "in series" with one of the leads coming from the track to the motor.
For lighting, the common connection for the two lights is the junction at the right.
Each lamp/LED will be attached to the short 'terminals' left of center.
This will result in a lamp wired across two rectifiers, resulting in an approximate?1.5 volt drop.
Then you just determine?which lamp lights when running in what direction.
Ken G.
I'm sure I've asked this before--and kind souls have answered it¡ªbut I am finally ready to put my Alco RSD-4/5 back together and (electronic ignoramus that I am) I don't know where to connect the leads from the motor nor the leads from the headlights and can't
find the answers previously provided.
I assume this is a constant lighting circuit, likely also with directional lighting.
My expertise usually extends only to using pre-wired LED's.
|
Re: Diode Lighting circuit
Labelled photo These appear to be 1 amp rectifiers (1N4001). SHOULD be okay for your engine. You might consider 3 amp if these one get really hot.
Ken G
I'm sure I've asked this before--and kind souls have answered it¡ªbut I am finally ready to put my Alco RSD-4/5 back together and (electronic ignoramus that I am) I don't know where to connect the leads from the motor nor the leads from the headlights and can't
find the answers previously provided.
I assume this is a constant lighting circuit, likely also with directional lighting.
My expertise usually extends only to using pre-wired LED's.
|
Re: Diode Lighting circuit
This circuit goes "in series" with one of the leads coming from the track to the motor.
For lighting, the common connection for the two lights is the junction at the right.
Each lamp/LED will be attached to the short 'terminals' left of center.
This will result in a lamp wired across two rectifiers, resulting in an approximate?1.5 volt drop.
Then you just determine?which lamp lights when running in what direction.
Ken G.
I'm sure I've asked this before--and kind souls have answered it¡ªbut I am finally ready to put my Alco RSD-4/5 back together and (electronic ignoramus that I am) I don't know where to connect the leads from the motor nor the leads from the headlights and can't
find the answers previously provided.
I assume this is a constant lighting circuit, likely also with directional lighting.
My expertise usually extends only to using pre-wired LED's.
|
I'm sure I've asked this before--and kind souls have answered it¡ªbut I am finally ready to put my Alco RSD-4/5 back together and (electronic ignoramus that I am) I don't know where to connect the leads from the motor nor the leads from the headlights and can't
find the answers previously provided.
I assume this is a constant lighting circuit, likely also with directional lighting.
My expertise usually extends only to using pre-wired LED's.
|
Re: S Helper 2-8-0 Consolidated DCC
The May 2017 NASG Dispatch has a complete article for replacing the drive gear on the SHS 2-8-0:
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This issue is available for viewing by non-members along with members.
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The gear is: Northwest Short Line part number 2930-6
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Rich G(ajnak)
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Re: Pennsy S Models Update
Thanks for the update Bill!
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Bill
Philadelphia
On 12/18/2024 6:23 PM EST Bill Lane via groups.io <bill@...> wrote:
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This is a brief update on the Pennsy S Models code 100 track project. I am very happy to announce Brian Jackson has joined the team as Chief Designer and Toolmaker. Brian has been learning injection mold design and production for a few years. He has the machinery to make it all happen. This will be his biggest project so far. Some preliminary design work has been started.
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So not only are all products going to be US made, the tooling design and production is going to be from a second generation S Scaler. You just can¡¯t get any better than that.
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Thank You,
Bill Lane
Modeling the Mighty Pennsy, PRSL & Reading in 1957 in S Scale since 1987
See my finished models at:
Look at what has been made in PRR in S Scale!
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See my layout progress at:
Join the Pennsylvania Reading Seashore Lines Historical Society
It's FREE to join!??
Preserving The Memory Of The PRSL
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This email has been checked for viruses by AVG antivirus software.
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Re: S Helper 2-8-0 Consolidated DCC
Here's the direct link:
- Peter.
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Show quoted text
On 12/18/2024 12:18 PM, EdSauers via groups.io wrote: Ted,
This is a common problem?with the SHS 280,? most likely the gear on the rear driver is split!!!!
There is a procedure on the NASG website on replacing this gear,
Ed Sauers
--
Peter Vanvliet (info@...)
owner, Fourth Ray Software
Houston, Texas
(personal web site)
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Re: S Helper 2-8-0 Consolidated DCC
Hi Ted, II don't know the specifics of this engine, but most are driven using a small section of poly hose on the shafts between the motor and the gear tower. If you can turn it upside down in a cradle and power the wheels you can see if it is the junction coupler tube or something more.
Rick Naylor
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 Confirming the dimensions...which I guess translates into 80".??
Robert, Would you have 3 sets of the 72" you would be willing to part with?
For reference, here is a Flyer chassis with 80" NIMCOs (the center driver is blind)
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-Robert Carter 
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For reference, here is a Flyer chassis with 80" NIMCOs (the center driver is blind)
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-Robert Carter 
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The grid is 12 inches. I'll have to take another look at the grades.
Rob Fuhst? Grand Haven, MI?
-- Rob Fuhst Grand Haven, MI
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Re: S Helper 2-8-0 Consolidated DCC
Ted,
This is a common problem?with the SHS 280,? most likely the gear on the rear driver is split!!!!
There is a procedure on the NASG website on replacing this gear,
Ed Sauers
On Wed, Dec 18, 2024 at 12:01?PM Ted Milliken via <mmtm1940= [email protected]> wrote: Good Morning:
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In regard to the above, is there anyone out there that does service work?? It appears that the drive between motor and driver gears are not engaging.? It has been running fine up until a few days ago when engine began to jerk along the track then nothing.? I am able to manually push engine along the track with all wheels freely rotating.? This is why I am assuming it has to do with the gears.? Any help? and suggestions would be appreciated.
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Ted Milliken
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Ben
Don Thompson
ken garber
Rick Naylor
Robert Carter