# Dumb question



## sanepilot (Mar 11, 2012)

Hi,all. what power do electric model rr switches[turnouts] need. Ac acessory side or Dc track side on a transformer? 

Many thanks,Everett Have a good day tomorrow.


----------



## michael cuneo (Sep 5, 2013)

Hi you should use the ac terminals


----------



## wingnut163 (Jan 3, 2013)

Ac acessory side or Dc track side on a transformer?


----------



## tr1 (Mar 9, 2013)

I believe it's the A/C acessory side.~15V A/C Of course dc Variable voltage
goes to the track.earlier I mis-typed.I ment that its a constant A/C voltage fluctuating at 60HZ.I'm sorry to have jumped in here.


----------



## hoscale37 (Nov 20, 2011)

AC terminals= Lights on the layout, turnouts, or other items that require power (railroad crossing lights...smaller things.)

DC terminals= ALWAYS and ONLY use for the track. Period.


----------



## rrgrassi (May 3, 2012)

hoscale37 said:


> AC terminals= Lights on the layout, turnouts, or other items that require power (railroad crossing lights...smaller things.)
> 
> DC terminals= ALWAYS and ONLY use for the track. Period.


My MRC has Variable DC (track), Fixed DC (On when transformer is on) and AC.

Variable DC, is for track only like you said.

I wonder what the Fixed DC is good for...I guess city and track side lights?


----------



## sanepilot (Mar 11, 2012)

*d question*

Hey,fellas..You`re the best. I should have known that.Things are hectic around here as usual.  I got more things planned than I`ll ever get done in three lifetimes.

TR1- Please don`t ever hesitate to answer my posts. I certainly appreciate any answers I get. I considerate the day wasted if I don`t learn something new every day and which I do.

Thanks,to all,Everett

Everybody have a good day and rest of week..Ta! Ta!:appl:


----------



## norgale (Apr 4, 2011)

I don't think any DC is "fixed' voltage. It's usually variable to control the speed of the train. The AC side is fixed to give you constant voltage to things like lights and other accessories. That AC doesn't mean it's alternating power does it? I think it means "accessory". However I just had a thought. Couldn't you hook lights up to the DC side of a spare transformer and use it like a dimmer switch to control the brightness of the lights? Pete


----------



## wingnut163 (Jan 3, 2013)

norgale said:


> I don't think any DC is "fixed' voltage. It's usually variable to control the speed of the train. The AC side is fixed to give you constant voltage to things like lights and other accessories. That AC doesn't mean it's alternating power does it? I think it means "accessory". However I just had a thought. Couldn't you hook lights up to the DC side of a spare transformer and use it like a dimmer switch to control the brightness of the lights? Pete


you are right on DC. a rheostat gives you variable control.

AC dose mean alternating current, just like the 120 ACV in the house. but from the power pack a transformer drops it down to about 17 v depending on your transformer. the AC is for your accessory's. 

as for you using the DC side for dimmer, there was just that said in another thread, seems you can.


----------



## DonR (Oct 18, 2012)

Power packs and Transformers don't really care that much
what you connect to their terminals so long as you don't
exceed their ratings.

So, you can use the old power pack when you convert to DCC as
a power source for lights, turnouts, and a multitude of accessories.

I use the variable (track) output for my LED panel lights. I can
vary their brightness.

I have a door bell transformer that, through a bridge rectifier
and capacitor discharge circuit power my turnouts.

Don


----------



## sanepilot (Mar 11, 2012)

*current*

O K,Ac is alternating current from o to 6o cycles.Dc is direct current. You cannot generate AC current. If I remember correctly you have to have a exciter to change dc to ac.That much I know. 
Now ,I have had several transformers apart,How do they change ac back into dc. I haven`t seen anything in the trannys that tells me anything about how they do it only different taps on the coil.Course the reostat controls the dc as far as variable power.What changes variable ac to dc in such a small coil?

You can`t generate ac only dc.It has to be changed to ac. Lets see a little correcting on this post.

Everybody have a good weekend,Everett


----------



## norgale (Apr 4, 2011)

That's what I'm saying. The transformer is DC all the way through. The track posts are for the tracks, DC, the AC posts are for [ac]cessories. Both are DC but the one for accessories is fixed and the track one is adjustable for the speed of the trains. To operate the transformer you plug it into a 110 outlet that is alternating current from your house. The "transformer" transforms the 110v AC to 12v DC and that's what you use to power your trains and accessories. Pete


----------



## wingnut163 (Jan 3, 2013)

you keep thinking that way, wrong , but you stay with it.


----------



## Southern (Nov 17, 2008)

Wingnut is right! The AC / Accessory out put is AC (alternating current). put a meter to it and check.


----------



## Southern (Nov 17, 2008)

sanepilot said:


> If I remember correctly you have to have a exciter to change dc to ac.That much I know.


I thought an alternator made A/C and a generator made D/C.


----------



## norgale (Apr 4, 2011)

Geeze! This is all very confusing. You mean to tell me that I'm wrong? That would be the first time this year. MMMMMMM! Pete


----------



## Southern (Nov 17, 2008)

hay Pete it is usually me that is wrong. Just ask my wife and kids.


----------



## norgale (Apr 4, 2011)

Ha! I wasn't sure about what I said but now I'm learning something. It's about time I got this transformer thing straight. I usually just hook up the wires, turn the thing on and see what happens. I lose a lot of lights that way. Pete


----------



## alman (Oct 22, 2012)

norgale said:


> That's what I'm saying. The transformer is DC all the way through. The track posts are for the tracks, DC, the AC posts are for [ac]cessories. Both are DC but the one for accessories is fixed and the track one is adjustable for the speed of the trains. To operate the transformer you plug it into a 110 outlet that is alternating current from your house. The "transformer" transforms the 110v AC to 12v DC and that's what you use to power your trains and accessories. Pete




A transformer either increases or decreases. Step up or Step down.
It does not transform from a/c to d/c.

That is what a rectifier does.

A train transformer for a d/c powered set , is actually a transformer /rectifier .


----------



## DonR (Oct 18, 2012)

This sure did get tangled up, guys.

Sure you can generate AC. Your car ALTERNATOR (Alternating
polarity) generates AC which is then rectified using diodes to provide the
DC that your car system uses and to charge the battery.

The old Generators on cars put out DC, originally 6 V later the
12 v we have now. (as an aside, those old tube type car radios
had to have a vibrator that converted the DC to AC which then
can be transformed to higher voltages needed by the tubes. You
cannot 'transform' DC.)

A Transformer, as used on Lionel, Marx and American Flyer, took
the 120 V house AC and 'transformed' it through coil windings and
induction into another coil that lowered the voltage to the 14 v AC or
so sent to the track by the rheostat speed control. It also has
another set of terminals that provides a constant 14 v ac or so
for Accessories.

A Power pack, as used on DC HO, N and other scales uses a
Transformer to reduce the 120 V house AC to about 14 volts
or so. That 14 ac voltage is available on the Accessory terminals.
It is also rectified into DC which is then sent to the track
through a rheostat speed control. It's polarity is reversed by the forward/
back switch.

Isn't something like this in the basic waring forum?

Don


----------



## sanepilot (Mar 11, 2012)

*acdc*

I`m gonna say this much: If you can generate AC,How come the large electric utilitys aren`t doing it. They save a bundle of money if so. Wow,we`re getting techinical now.

A dumb question has turned into generating power discussion. I`ve certainly enjoy this so far and lo and behold learned something.:appl:

Everybody have a good sunday,Everett


----------



## norgale (Apr 4, 2011)

So with a transformer for our trains it's 110v AC in and 12v DC out to the track and 12v AC out to the accessories? Do I got it right now? Geeze I'm electrically challenged. You think this is fun wait till I get my DCC set up. Ha! Pete


----------



## DonR (Oct 18, 2012)

You're getting close Pete.

It seems most of the guys on the Forum refer to a Power Pack for
DC trains as a transformer. Actually, the transformer is the
coils of wire inside the power pack that drops the voltage from the
120 house current to the 14 volts or so. A rectifier in the power
pack converts the AC to DC for the track. The accessory
terminals are AC at 14 volts.

The device that is used for Lionel, Marx and American Flyer trains was
actually called a transformer. It only output AC, controlled for the
track, and not controlled for accessories.

Don


----------



## gunrunnerjohn (Nov 10, 2010)

sanepilot said:


> I`m gonna say this much: If you can generate AC,How come the large electric utilitys aren`t doing it. They save a bundle of money if so. Wow,we`re getting techinical now.


All the utilities generate AC, so I don't understand this statement at all.


----------



## norgale (Apr 4, 2011)

Does that mean you couldn't run some lights off the track side (DC) like a dimmer switch? Pete


----------



## DonR (Oct 18, 2012)

...My son is an engineer in California. He tells me that in fact,
some utilities do have DC generation for special purposes. They have
found that by generating DC, then inverting it to AC so they can increase
the voltage by transformers to the high line level, then again
rectifying it back to DC they are able to transmit it with lower line loss
than with AC. This is being done with a long line from Oregon to
Los Angeles area, carrying 500 kv of power and in other
countries around the world. Wikipedia has a
lot of information on the issue.

...The systems initially built by Thomas Edison were DC. He worked with
General Electric on his systems. However, Tesla and Westinghouse were
the winners in the battle with the AC system we know today.

...The solar panel farms generate DC, which in usually converted
to AC before joining the grid.

...Have to say...this sure surprised me as I thought DC died
with the advent of AC But it be de trute. 

Don


----------



## DonR (Oct 18, 2012)

norgale said:


> Does that mean you couldn't run some lights off the track side (DC) like a dimmer switch? Pete


Pete

Sure you can run lights with the DC (track) side using the speed
control as a dimmer. I'm powering my panel LEDs using the track
voltage of an old Power pack . The speed control reduces the 
voltage and I can adjust to the brightness I want.

Even so, I have protective resistors in the circuit.

However, I don't think you'd want to drain amps away from trains
for lights. Run your lights etc. from the Accessories terminals.

Don


----------



## golfermd (Apr 19, 2013)

sanepilot said:


> I`m gonna say this much: If you can generate AC,How come the large electric utilitys aren`t doing it. They save a bundle of money if so. Wow,we`re getting techinical now.
> 
> A dumb question has turned into generating power discussion. I`ve certainly enjoy this so far and lo and behold learned something.:appl:
> 
> Everybody have a good sunday,Everett


A/C is much more efficient for transmission than DC, which is why power companies use it.


----------



## sanepilot (Mar 11, 2012)

*power*

Hi,all. I have never checked how much the ac side was putting out. I know it is enough to blow a 15 watt led bulb.somebody said about 15 volts,that sounds about right. I`m gonna check mine when I get the chance.Myself,I don`t like electricity or anything I can`t see. Boy,does it bite tho,so I know it is there.

New week starting,everyone have a good one.Everett

Youre right Donr.. Anyone living close to a high tension power line,Take a floursecent lightbulb on a rainy damp day and get under it and hold it as high in the air and it will light. My hair[when i had it] would stand up as I walked under the wires. Don theyre in the process of building a 500 kv thru wv to the south somewhere but theyre having trouble getting right of ways.and epa permission ,state also. Good ole politics


----------



## gunrunnerjohn (Nov 10, 2010)

DonR said:


> ...My son is an engineer in California. He tells me that in fact,
> some utilities do have DC generation for special purposes. They have
> found that by generating DC, then inverting it to AC so they can increase
> the voltage by transformers to the high line level, then again
> ...


99% of all the generation is still AC. It's just so simple, it's hard to get the utilities to spend the massive amount of money for the high voltage DC transmission.


----------



## tr1 (Mar 9, 2013)

*AC= Alternating Current dc= direct current*



norgale said:


> I don't think any DC is "fixed' voltage. It's usually variable to control the speed of the train. The AC side is fixed to give you constant voltage to things like lights and other accessories. That AC doesn't mean it's alternating power does it? I think it means "accessory". However I just had a thought. Couldn't you hook lights up to the DC side of a spare transformer and use it like a dimmer switch to control the brightness of the lights? Pete


dear sir's, dc is a fixed steady state voltage. Example 15v dc looks like this--------- 15Vdc A straight line at 15 Vdc of amplitude while Ac oscillates up and down.15VAC oscillates from 0 volts up to plus +15V of amplitude the result is a sign wave of a positive(+15v) up and down to a (-15v ) up to ( +15V) up plus to minus with 0 in the middle. 
0V /\/\/\/ = sine wave
60Hz is the frequency of oscillation's I per second :eyes: I hope I didn't confuse you guy's.

Regards, 
I'm open to any questions regarding this topic.
tr1


----------



## DonR (Oct 18, 2012)

Oh yes, no argument. As you say, John, 99% of the power
we use comes from AC generators. I was just as surprised as
anyone when he told me of the growing DC generation and
transmission lines. Of course, it's again inverted to AC when
it gets to the destination utilities.

This system seems contrary to logic because of t he need to convert
the DC to AC then to DC and finally back to AC. That would take
massive conversion facilities that would cost a great amount of $.
But the claim is that by doing so they reduce line loss sufficiently
enough to make it a profitable system.

Wikipedia lists a number of huge projects using this system in
Europe, South America and, not surprisingly, China. The system
was developed by a European company working with...are you
ready...GENERAL ELECTRIC...who was Edison's partner in their
original DC system that lost out to Tesla and Westinghouse.

Don


----------



## alman (Oct 22, 2012)

*Basic transformer / rectifier.*

Hope this helps !


----------



## tr1 (Mar 9, 2013)

*dc= direct current,AC=alternating current*



norgale said:


> I don't think any DC is "fixed' voltage. It's usually variable to control the speed of the train. The AC side is fixed to give you constant voltage to things like lights and other accessories. That AC doesn't mean it's alternating power does it? I think it means "accessory". However I just had a thought. Couldn't you hook lights up to the DC side of a spare transformer and use it like a dimmer switch to control the brightness of the lights? Pete


I'm sorry to have "bud" in here.
Regards,
tr1


----------



## tr1 (Mar 9, 2013)

*A/C, dc & MRR*

I will try again, As far as I know dc is a fixed voltage Approximately (~15V).This can be varied with a rheostat: voltage, controller/ throttle. AC voltage,
A constant A/C voltage (~10V). lets say. Now, that is a fluctuating current, (Alternating).A/C This is used over longer distances so that voltage drop doesn't occur. This type of voltage is controlled with resistor's either fixed or variable in ohms.
Regards,
tr1
PS I'm open to any questions you may have.
Thank you,
tr1


----------



## tr1 (Mar 9, 2013)

*This gets confusing*

:hah:Lets discuss how a 555 timer is an invaulble IC chip in the model railroading hobby of digital electronics.


----------



## tr1 (Mar 9, 2013)

*dcV from A/CV*



sanepilot said:


> O K,Ac is alternating current from o to 6o cycles.Dc is direct current. You cannot generate AC current. If I remember correctly you have to have a exciter to change dc to ac.That much I know.
> Now ,I have had several transformers apart,How do they change ac back into dc. I haven`t seen anything in the trannys that tells me anything about how they do it only different taps on the coil.Course the reostat controls the dc as far as variable power.What changes variable ac to dc in such a small coil?
> 
> You can`t generate ac only dc.It has to be changed to ac. Lets see a little correcting on this post. Everybody have a good weekend,
> Everett


How do they change (convert) A/C V back to dc V, I believe was the question ?
To change (convert A/C to dc. The voltage is rectified with diodes.The diodes block the negative cycle of the A/C sine wave which then produces a steady state ---------------voltage. With the negative cycle eliminated dc current is produced, wa la dc voltage or direct current results .Any thing further I'll reference my text books. If there's
any additional questions I,ll be happy to try and reply.
Regards,
tr1


----------



## tr1 (Mar 9, 2013)

*IN Addition:A/C V rectification=dc v*

from what I remember, I'll try too explain. Dc v (direct current) occurs when the A/C
Alternating voltage is rectified).This happens with the use of diodes that are capable of blocking half of the sine wave. Hope this helps. But I'm sure further explanation is needed.
Regards,
tr1


----------



## tr1 (Mar 9, 2013)

*(A/C)Alternating Current rectified=dc(direct current)*

I think a electrical forum is needed for model train applications
Regards,
tr1


----------



## sanepilot (Mar 11, 2012)

*ac generation*

Hi,all. I`m afraid to jump back in here,might show my dumbness., If you can generate ac power,why do you need a exciter to generate ac electricity. Isn`t electricity just the changing between north and south magnets[poles] basically with a armature and fields? 

Oh,yes,by the way- Do we have any electrical engineers on the forum.This has turned into a very nice discussion. or better yet any power plant workers?Just curious..

New weekend coming up. Whatever you do,remember your mother this weekend:appl:,sanepilot


----------



## Big Ed (Jun 16, 2009)

sanepilot said:


> Hi,all. I`m afraid to jump back in here,might show my dumbness.
> 
> New weekend coming up. Whatever you do,remember your mother this weekend:appl:,sanepilot



It is your thread you know? 
And the title is "Dumb question". 

What I do know, stick a fork into an electrical outlet and you will feel what electricity feels like.


----------



## gunrunnerjohn (Nov 10, 2010)

The reason that DC power is more efficient to transmit comes down to the fact that it doesn't change directions 120 times a second. It takes energy to do the reversals, about 6-7% for high tension lines. It takes less energy to transmit DC, not only do you eliminate the reversal losses, but DC doesn't suffer from "surface effects", and uses the whole conductor. You can therefore handle greater current in the same sized wire as AC.


----------



## sanepilot (Mar 11, 2012)

*dumb question*

right,John..electricity travels on the outside of the conductor not thru the the conductor.I hate something I can`t see.I don`t think I`ll ever quit learning.

Hey,ed,after all these years I`ve found out what forks are for.

Don`t forget MoM,sanepilot


----------



## Gansett (Apr 8, 2011)

I'm shocked this thread lives on, shocked I tell ya.


----------



## rzw0wr (Aug 28, 2013)

When I first started learning about electronics, I read that the USA went with AC because you could have longer transfer line.
With DC you would have to build a power station about every 2 mile of line.

Did I miss something?


----------



## gunrunnerjohn (Nov 10, 2010)

Times have changed. When the world went AC, there were not efficient AC/DC conversion capabilities, and AC was the clear choice for distribution. Now things are not so clear, so DC is making a comeback, though I suspect much of our power infrastructure will be AC for decades to come.


----------



## sanepilot (Mar 11, 2012)

*dumb quetion*

Hi,everyone.. You are right ,Gunny. this old world gets wiser and wickeder[ My speech instructor said there ain`t such a word as wickeder.. What that advertisement say.. It doesn`t get much better than this.

Hay,Jackc..that is shocking news to hear.

I gotta ketch up on my bookwork,whatever u do ,have fun,sanepilot


----------

