# Why does it take so much power?



## jjb727 (Apr 13, 2012)

So im running my trains and trying to see which is the better-suited transformer for them. I have the following transformers:


Life-Like Blue box transformers: These come with every train set that is under the Life-Like line of trains and are the most basic of the transformers out there. They are not very powerful for they only give an output of about 7amps (or so Im told). When I start running the trains with these, I notice that the trains dont start moving until after the speed cursor reaches the 1/2 way point. 

Bachmann Speed Controller- A little better than the Life-like power transformers, but still, some trains do take more power to start moving at slow speeds. On this one, the bachmann locomotives start moving the speed controller/throttle reaches almost 1/2 way (either direction). 

MRC 280 (double throttle)- For some reason, this one starts doing the same thing that my Life-like throttle does, it takes more power for the trains to start moving slowly. Shouldn't MRC power transformers be more powerful than standard blue life-like transformers? 

Idk, that's just me....

I will be making a video of this today.


----------



## HVF City (Jul 14, 2012)

Running standard DC controls could be related to your accelerator in your car. A little more push on the pedal until moving, then just a touch to keep at a give speed. Here, any difference between throttle position between brands (and even between equal models of the same brand) are manufacturing tolerances. So what you are seeing is normal for standard DC locomotives on base level controls.

Now, MRC does have units with pulse (I had one, but can't recall exactly) that help in slow speed operation and acceleration, however, these do have a result of extra heat and wear on the drive motor. How much depends on a lot of factors. But if you wish to stay DC, buy a good controller that you can turn on and off pulse and just have fun.

Or, go DCC and you will have some very realistic operations. I did and even the Wife says it was the right move.

Bill


----------



## jjb727 (Apr 13, 2012)

Would adding that oil that helps with power pick up on the tracks help make a difference at all?


----------



## HVF City (Jul 14, 2012)

Not being there, I would say no. I'm a clean wheels, clean track is best kind of guy. There are area's to lube on an engine if it is older or had a lot of run time on it, but putting anything on the track in my opinion and history just makes the engine slip.


----------



## jjb727 (Apr 13, 2012)

I think its a lubricant for the engines that helps draw less power from the track in order to run more smoothly.


----------



## rrgrassi (May 3, 2012)

Freer running motors and drive lines help that issue. Never heard of an oil that lets a motor draw less power. Only tweaking or remotoring will do that.


----------



## jjb727 (Apr 13, 2012)

Well, i think i got the idea wrong. The oil improves the way the engine draws power from the track. My bad...


----------



## blues90 (Apr 7, 2008)

I only did have the old DC transformers . I have two newer MRC black plastic one has the pulse but I never liked the way it acted and didn't trust it. I also have two older MRC that are copper colored and one has two controls and an amp and volt meter . the other is just one control and less amps. 

All I know is if you run one loco and right now I don't know what their amp rating is . Basically the more amps the more loco's can be run at one time. The most I could get was 4 atlas loco's on the newer plastic MRC transformers but even then the circuit breaker would break the circuit . One the larger copper metal transformer I could run 4 loco's all I wanted. 

The only way to really tell is to place an amp gauge in the circuit to see just how many amps a loco draws . If it's real high and again right now I can't tell you what they should draw then something in the loco is drawing more current due to either how many cars you are pulling or perhaps the loco has gears or something binding or bad motor brushes or dirty track ie anything that causes high electrical resistence. 

If I recall the balck plastic MRC transformer with pulse I had is a 2400 .

It's been so long like 1983 when I had a 4x8 layout I just can't remember mostly I used to large copper metal MRC power pack and the most I ran were three loco's because of the small layout . In some railroad Magazine had a schematic of a hand control using radio shack parts so I made the transister control that did the pulse thing much better . I can't even recall how I connected it now it had 4 wires and I still have it. It had its own reverse switch and reostat which was just a potentiometer and a huge transister with a huge heat sink. 

If you have a amp gauge even a DVOM would work and placed it in circuit say the pos side rail you could tell what the loco was drawing amp wise. I know on the smaller copper MRC transformer I replaced the old style wafer rectifier with a larger radio shack 4 diode 4 amp one because the power pack would not work and I may have done the same thing with the larger copper one. A rectifier converts A/C to D/C . 

I know this doesn't help much with all this electrical jargen but you may be able to pin down what the issue is if you can read what the loco draws and then find the issue. If I recall I used a radio shack 2.5 amp 12 VDC power pack regulated power supply with the homemade walk around controller I made. You said 7 amps , that sounds pretty high to me for any small power pack or transformer. Looking at a 1994 Walthers catalog the highest MRC is 2.5 amp the 2400 is 1.65 amp . I can't say what the newer ones are. Yet 1.65 amp can run 4 to 5 loco's depending on what they draw.


----------



## jjb727 (Apr 13, 2012)

Well, I also have power-loc track that my trains are running on, so theres a lot of joints causing more and more resistance (which is why most of my temporary layouts are small)

(yea, Power-loc sucks, but on my budget, its what i can do)


----------



## Howard1975 (Jan 6, 2014)

jjb727 said:


> So im running my trains and trying to see which is the better-suited transformer for them. I have the following transformers:
> 
> 
> Life-Like Blue box transformers: These come with every train set that is under the Life-Like line of trains and are the most basic of the transformers out there. They are not very powerful for they only give an output of about 7amps (or so Im told). When I start running the trains with these, I notice that the trains dont start moving until after the speed cursor reaches the 1/2 way point.
> ...




That Life Like power pack is probably closer to 0.7 VA, which is a common rating for the small train set power packs. Same with the Bachmann, it should be somewhere around that rating also. Your MRC Tech 4 model 280 is rated at 16 VA. 

I can understand that you need to turn the dial to the 1/2 mark on the Life-Like and Bachmann controllers, to get your train moving. But you should not need to do that with the MRC Tech 4 unit. It's a much more powerful controller, and updated circuitry inside for smoother slow speed control. I have a couple MRC Tech II power packs, the 2500 model with 16 VA, which work very well for me. I don't need to turn the dial to the 1/2 mark, to get my locomotives moving. Some of my loco's start moving at the 1/4 mark, some even need less to get moving. Although I should mention in fairness, my MRC Tech II 2500 power packs output 20 volts, while your MRC Tech 4, 280 is rated at 14.5 volts output for each cab. 

You might want to take a closer look at your locomotives perhaps. They might need a good cleaning of any crude and gunk inside, which is usually dried out lubrication, carpet fuze, hair, etc. Once everything is clean inside, and the wheels are also clean, then add a tiny amount of new oil (or grease) to the moving parts. 

Sometimes the motor itself is tired and weak, from lot's of running. Sometimes when they get worn out, they need the armature cleaned and the brushes replaced (if the motor is even serviceable). 

Also check for any binding in the drive train, or cracked gears, as that will create problems also. 

A properly cleaned and lubed loco (with a good strong motor) will need less amperage to operate. It will have a lower starting voltage (and therefore speed), which is always nice for smooth switching. 

If you had an amp meter, you could do an experiment. Test a loco before doing maintenance, and then test again after maintenance. The amperage should be lower after cleaning and fresh lube. Also do anything you can do to improve your electrical path. Make sure all electrical pickups and connections are clean and tight, with a good solder joint. They can come lose or even break when a wire is pulled too hard. 

Howard


----------



## jjb727 (Apr 13, 2012)

i'll try taking my locos to the hobby store to see if they need some kind of maintenance. I dont think that a much more powerful transformer should be failing to accelerate my locos at low speed.


----------



## norgale (Apr 4, 2011)

Oiling the track and wheels just picks up that much more dirt and grime. Not a good idea. Make sure all the track is really clean and the wheels too. Other than that I don't know. Pete


----------



## Rusty (Jun 23, 2011)

What brand is your locomotive?





.


----------



## ggnlars (Aug 6, 2013)

There are additives that people put on the track, graphite and no-ox to name a couple. These both reduce the electrical power the motor sees relative to purely clean track and wheels. The problem is clean does not stay that way long. Dirt and crud on the wheels and track quickly kill the power to the motor. Think of a dimmer switch, with the additives, the dimmer is at 85%. Dirt will take the dimmer down considerably more than this. Rapidly limiting the range of operation of your engines. 
The additives are said to retard or minimize the build up of the dirt and crud, keeping the dimmer near the 85%. Thus maintaining most of your operating capabilities. 
Be careful, putting these on the surface will make the track and wheels slippery. This will reduce the adhesion capability of locomotives. This will give you problems with grades and long trains, again reducing your engines operating capabilities.
As was mentioned earlier, the key parameter from a power supply is the VA rating. That is the maximum electrical power rating. 
The electric motor is a power converter. It converts VA, (usually called Watts) to horsepower which is used to drive the wheels. Applying a voltage to a motor, it will initiate the rotation of the shaft. The rotation will stabilize depending on the load own the shaft. As long as the supply has the capacity, the motor will draw the current to provide the power for the load at this speed. 
When the motor rotor or drive has restrictions of any form, this increases this load requirement. Thus increasing the current to provide the power to over come this added load. This balancing act will result in a reduction in motor rpm and thus loco speed. 
The electrical motors used in these engines have a current limit. This occurs at motor stall. 
This number is critical in the DCC world, because the decoders are sized based in this number. It is not as critical in the DC world. Operating engines near this number limits the motor life and will restrict the number of engines that will run in a block. The power supplies are max power and temperature limited with internal circuit breakers. This is to limit the impact of short circuits. When drawing near the max power the supply will shut off like there was a short. 
Bottom line, your power supply needs to have the capacity to handle your railroad and your loco's need to be tuned to minimize the unwanted loads. You want the load to be train cars not crud.
Finally, pulse voltage is the favorite means to get these moors to run at engine speeds 5 smph or less. Today, all DCC decoders use it. Later motors have been redesigned to minimize the adverse impact of the pulsing. Older motors did have problems with over heating. If the motor feels luke warm to the touch, you have lost half the motor life. That is true or over loading as well as pulsing. 
Most DC power supplies today allow you to turn the pulsing on and off, mainly to minimize any motor problems. The pulse does little good in DC at speeds above 20 smph. 
In DCC, the decoder uses the pulsing to get needed info from the motor. Thus, it uses some pulsing over the entire operating range. What this means is if your going to DCC, you should question doing it with older motors. How old? Probably newer than 10 years. You can convert older systems, but they won't do as well. And depending on use, they won't last very long. 
I realize this is wordy, but I've been researching the overall subject and it is fresh in my mind.
Good luck,
Larry


----------

