# This is probably a fool's errand..



## DKRickman (Mar 25, 2008)

One of these days, I'll finish my first large scale loco. When I do, I have to power it, so I've read with interest the various discussions about Battery power vs. DCC vs. DC, etc. I tend to agree with the folks who say battery power is the way to go, right up to the point that they start talking about radio control systems. I really like the onboard power source, but I am not keen on investing in radio transmitters and receivers. I'm a cheap s.o.b. who is building an engine because he can't (or won't) spend the money to buy even a $200 loco. I like using what I already have, or can get cheaply.

As far as I can tell, the RC aspect of battery power fails the cheapskate test. Now, I'm not broke, but I can't get SWMBO to accept hundreds of dollars in expenses, especially after begging for years to get a $150 DCC system for my HO trains. I know there are simpler things, like critter control, but I would prefer to be able to control my train remotely - meaning not having to touch it to make it go or stop.


All that lead up to what may be a really dumb idea. Wouldn't it be possible to control a train via a signal or voltage on the rails, but supply the power from a battery? The advantage over track power would be that the engine would continue to run smoothly, although a loss of "signal" might mean a loss of control - I would have it simply keep doing whatever it was before it lost contact. Somewhere around here I have an old Lionel ZF - maybe it would make a good control, possibly even using physical or electronic E-units for reversing.


I'm sure the idea of a hybrid track & battery system will infuriate purists in both camps, but it seems to me that both have their advantages, and they could be used to compliment each other. Best of all, it seems like it could be an inexpensive way of improving on a track powered system.


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## Jerry McColgan (Feb 8, 2008)

Posted By DKRickman on 07 Jul 2011 08:02 PM 

I'm sure the idea of a hybrid track & battery system will infuriate purists in both camps, 



You are beyond my level of expertise but you seem to have a similar concept as the hybrid system Aristo-Craft mentions in their new Revolution brochure. The difference is that they appear to use constant track voltage to keep the battery charged but power the loco from the battery.

There are some pretty cheap battery powered RC trains (I bought some for $10 new in box) so perhaps that might be a way to go to get a cheap RC signal to the loco.

Putting the signal on the rails sounds troublesome to me because I have read where others have had problems getting the DCC or DCS signals to work well. Those problems have apparently been worked around but I wonder about a signal without power.

Then too I would not know where to start but I see nothing wrong with what you are trying to do. Sometimes the most enjoyment comes from accomplishing what everyone says is impossible.

If you infuriate purists in both camps I would think that to be a positive rather than a negative. We need to find ways to expand what we can do - not accept limitations just because they happen to be the status quo.

Jerry


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## East Broad Top (Dec 29, 2007)

Not sure about sending control signals over the rails, but if you're looking for inexpensive, perhaps you could combine a critter control with a traditional R/C 2-channel radio. Use the servos to turn the knob and throw a DPDT switch for direction. You may be able to get a 75mHz R/C system pretty cheap used as many R/C guys are converting over to the newer 2.4 gHz stuff. You'd have to figure out the linkage from the servo to the knob, but live steamers have been doing similar things and can probably point you in the right direction there. 

Later, 

K


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## fred j (Jan 12, 2011)

Posted By DKRickman on 07 Jul 2011 08:02 PM 
One of these days, I'll finish my first large scale loco. When I do, I have to power it, so I've read with interest the various discussions about Battery power vs. DCC vs. DC, etc. I tend to agree with the folks who say battery power is the way to go, right up to the point that they start talking about radio control systems. I really like the onboard power source, but I am not keen on investing in radio transmitters and receivers. I'm a cheap s.o.b. who is building an engine because he can't (or won't) spend the money to buy even a $200 loco. I like using what I already have, or can get cheaply.

As far as I can tell, the RC aspect of battery power fails the cheapskate test. Now, I'm not broke, but I can't get SWMBO to accept hundreds of dollars in expenses, especially after begging for years to get a $150 DCC system for my HO trains. I know there are simpler things, like critter control, but I would prefer to be able to control my train remotely - meaning not having to touch it to make it go or stop.


All that lead up to what may be a really dumb idea. Wouldn't it be possible to control a train via a signal or voltage on the rails, but supply the power from a battery? The advantage over track power would be that the engine would continue to run smoothly, although a loss of "signal" might mean a loss of control - I would have it simply keep doing whatever it was before it lost contact. Somewhere around here I have an old Lionel ZF - maybe it would make a good control, possibly even using physical or electronic E-units for reversing.


I'm sure the idea of a hybrid track & battery system will infuriate purists in both camps, but it seems to me that both have their advantages, and they could be used to compliment each other. Best of all, it seems like it could be an inexpensive way of improving on a track powered system. 


I like your ideal, but i think the REVO is too expensive for what your looking to do.
It will be interesting to follow this thread to see what some of the people in the know
will come up with. This could be the start of something wonderful.


Fred


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## Greg Elmassian (Jan 3, 2008)

This would be pretty easy to do, a couple of cheap relays, some track that does conduct electrically. 

Put 2 relays in the loco, like 12 volt ones, connect them to the track pickups, but put a diode in series with each, reverse one diode. 

Now wire the power from the battery through the relays, in such a way that one relay makes it go forward, one in reverse. 

Put 12 volts on the rails, the train goes forwards, reverse the leads, and the other relay kicks in and it goes backwards, take the power off the track and it stops. 

You can do this for about $10, plus your battery. 

Cheap enough? 

Greg


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## Del Tapparo (Jan 4, 2008)

Posted By Greg Elmassian on 07 Jul 2011 10:09 PM 
This would be pretty easy to do, a couple of cheap relays, some track that does conduct electrically. 

Put 2 relays in the loco, like 12 volt ones, connect them to the track pickups, but put a diode in series with each, reverse one diode. 

Now wire the power from the battery through the relays, in such a way that one relay makes it go forward, one in reverse. 

Put 12 volts on the rails, the train goes forwards, reverse the leads, and the other relay kicks in and it goes backwards, take the power off the track and it stops. 

You can do this for about $10, plus your battery. 

Cheap enough? 

Greg 
Or how about this? Just eliminate the batteries, the relays, and the diodes. Apply 12V to the track, the train goes forward. Reverse the leads and the train goes backwards.









Of course with the relay deal, aside from stripping gears, your track only has to be clean enough to get the 12V command to work, eventually, when you hit a clean spot, with your clean wheels. (You would also need latching relays wouldn't you?). 


I still like the Critter Control idea.







Edit: Not Kevin's idea. Why do that when you could just buy the same Critter Control hardware programmed for 2-channel R/C. Used to call it the Basic RailBoss.


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## DKRickman (Mar 25, 2008)

Posted By Greg Elmassian on 07 Jul 2011 10:09 PM 
This would be pretty easy to do, a couple of cheap relays, some track that does conduct electrically. 

Put 2 relays in the loco, like 12 volt ones, connect them to the track pickups, but put a diode in series with each, reverse one diode. 

Now wire the power from the battery through the relays, in such a way that one relay makes it go forward, one in reverse. 

Put 12 volts on the rails, the train goes forwards, reverse the leads, and the other relay kicks in and it goes backwards, take the power off the track and it stops. 

You can do this for about $10, plus your battery. 

Cheap enough? 

Greg 
Greg,

I'm not sure if you were being sarcastic or serious, but I think you've got the gist of my idea pretty well. I'm not sure the single speed thing is a good idea, but overall it seems like it could be tweaked to work well.

I like it!


I'm thinking you'd want a capacitor to the track input, so that a momentary loss of continuity would not stop the engine. On the other hand, maybe a capacitor on the motor would be better. That would do all the usual momentum things, and smooth out the single speed jerkiness. A skilled hand could control speed by pulsing the power..


In fact, a pulse power supply would do the same thing, but you might need a solid state relay to switch on and off fast enough.


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## Greg Elmassian (Jan 3, 2008)

Nope, not sarcastic at all, tried to think of the simplest thing I could. (In other words trying to fit your original request) As long as there is a little bit of conductivity, the relay will engage (most 12v ones will work down to 9v or less), and since very little power is used for the relay, track cleanliness and conductivity is much less important. 

Yes, actually a capacitor across each of the relay coils (cannot put on the track because you are reversing polarity)... and yes, you could do some simple stuff to modulate the radical on-off of the motor, like some more caps and diodes.. 

I think you could do it as you asked, really cheap, and get something that works. Now, if you did not want reverse, you could probably make it 2 speeds in forwards... 

Most likely a little more circuitry and a couple of voltage comparators and you could get multiple speeds, but at that point, the cost would start increasing. Then I would look into cannibalizing an inexpensive toy R/C car for $20 and adapting it to the loco. It might have enough current for a very small loco. 

Regards, Greg


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## toddalin (Jan 4, 2008)

The relays could work, and multiple speeds could possibly be achieved using a relay "stepper" circuit. It may be possible to pulse the relay, and each pulse increases the speed by advancing to the next relay using fewer diodes between the battery pack and motor to increase the voltage. Reverse current could create a stop by pulsing a release relay, or maybe even pulsing back down through the stepper circuit (more complicated).

The two relays on the left (Relay 1 and Relay 2) show how one can create a "latching relay" using ordinary relays. The first pulse turns it on and the next pulse turns it off. The pulses would be supplied through the track then the on-board batteries are used in the "latching." Using this concept, additional relays could be added, each setting itself and turning off the prior one in the sequence. With 9 relays, you may get to "Run 8."



Another possible way to do it is to use various voltages to trigger various relays. For example a 6 volt pulse may trigger one relay while a 12 volt pulse may trigger both, with the armature of the higher voltage relay superceeding the lower voltage unit.


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