Model Train Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
662 Posts
Discussion Starter #1 (Edited)
this application is perfect for providing 120 volts at a remote location without having to run a 120 volt line. you can run a low voltage line and step it up to 120 volts at the remote end. make sure your wire is of sufficient gauge for the load your running, in this case a simple light bulb can be run on 16 gauge zip cord, a 100 watt light bulb can be powered with ordinary zip cord distances up to 100 feet. at 100 feet a 16 gauge cord can carry 5 amps with no problem, in this case running a simple 100 watt incandescent light bulb will draw .083 amps.

this is used widely in industry for powering remote devices without having to run 120 volt wall current, you can run 15 volts and step it up at the remote end.

as an addendum, there are lots of regulations you have to comply with if your sending line voltage across the room, however there are no regulations for sending low voltage across the room of any kind...

 

·
Registered
Joined
·
137 Posts
I realize I am a newby here and if this gets me kicked off these forums that is fine.
As a 40 year licensed electrician I strongly advise that there are many much safer ways to accomplish the same goal.
 

·
Registered
Joined
·
662 Posts
Discussion Starter #3
this was a practical DEMONSTRATION of how a step up transformer works, i can guarantee you that virtually no one knew this was possible using two common train transformers. there is nothing unsafe about the application, low voltage is much safer than running line voltage without the need of romex and conduit. as far as being an expert, you will have some competition, we have a guy on the forum thats an expert at EVERYTHING.

i do lots of experiments and demonstrations to enlighten people, i find them fascinating, others find them terrifying, i can remember as a child after doing an experiment, my grandmother waggled her finger at me and said "benjamin, someday your going to be hung", i always wondered how she knew.

in any case, i go out of my way to do demonstrations of usually forgotten or generally unknown applications, like purifying alcohol with salt. it works but no one knows about it...

 

·
Admin
Joined
·
44,359 Posts
in this case running a simple 100 watt incandescent light bulb will draw .083 amps.
Neat trick running a 100W bulb on around 10 watts, how did you accomplish that? ;)

120 * .083 = 9.96 VA or in the case of pure AC, 9.96 watts.
 

·
Admin
Joined
·
44,359 Posts
Neat trick running a 100W bulb on around 10 watts, how did you accomplish that? ;)

120 * .083 = 9.96 VA or in the case of pure AC, 9.96 watts.
FWIW, anyone that understands how a transformer works knows that you can step up or step down voltage. Look up, you'll see 750,000 volt power lines, how do you think they get the voltage that high? ;)
 

·
Registered
Joined
·
662 Posts
Discussion Starter #7
i think you missed the point here, as i said virtually no one knew you could do this with common TRAIN TRANSFORMERS, i wasnt trying to start an argument i was doing a demonstration of whats possible. if i posted a video on needle point some one on this forum would point out the dangers of eye strain and carpal tunnel syndrome.
 

·
Registered
Joined
·
561 Posts
FWIW, anyone that understands how a transformer works knows that you can step up or step down voltage. Look up, you'll see 750,000 volt power lines, how do you think they get the voltage that high? ;)
captured lightning bolts!!!!!

i think you missed the point here, as i said virtually no one knew you could do this with common TRAIN TRANSFORMERS, i wasnt trying to start an argument i was doing a demonstration of whats possible. if i posted a video on needle point some one on this forum would point out the dangers of eye strain and carpal tunnel syndrome.
That only happens with Red Rider BB-Guns... :cheeky4:


thx.. that was pretty nifty...
 

·
Registered
Joined
·
3,469 Posts
just as a matter of interest ... say that you have 100 watt light bulbs on the far end, two of them, for a total of 200 watt ...
assuming 100 per cent efficiency [which unfortunately isn't the case], you would have over thirteen amps of current in the low voltage [in your case fifteen volt] line ??
that's pretty close to the maximum current for sixteen gauge connector lines ?? wouldn't leave much for other devices ???
 

·
Registered
Joined
·
8,907 Posts
There is a lot here I disagree with. I think people who understand transfromers realize that they do, fundamentally, work backwards as well as forwards, so I think alot of people "knew" that this would work - if they stopped to think about it. Their impedances and fault current smay not be what you like, or what you'd design in a unit engineering from the get-go for that direction, but they will work. Physics sort of guarrantees that.

And I will more than quibble about the "safe" thing. Not that its a bomb ready to go off, but the breaker isn't necessarily going to work. All sorts of things happen when you "reverse flow" a transformer, some only inconvenient, but often, affecting protection for faults and voltage regulation

And I agree with GRJ - don't understand the math behind powering the bulk with that power in
 

·
Registered
Joined
·
2,213 Posts
The low voltage current exceeds the Marx transformer's capabilities. The low voltage current exceeds 16 AWG wire's maximum recommended amps for transmission beyond chassis wiring.

I recommend updating or deleting the thread. Members without electrical knowledge may attempt this with disastrous results.
 

·
Registered
Joined
·
207 Posts
I see you Ben.

Us tube heads do this a lot with guitar stomp boxes. To operate, tubes need well over 100VDC (Fender and Marshall run some B+ circuits at 300V for pre-amp tubes). The kicker is that we don't usually have the room in the average sized stomp box for a full power supply (120v input). What we end up doing is taking a 120V x-fmr that has a 12V NO LOAD (that's the key) secondary. Usually we end up with a "secondary" in the 8-10V range to get a 12V no load measurement.

We then consider 12Vac as the official supply voltage for the stomp box. The heaters run directly from this 12Vac supply. Running "backwards" through a small x-fmr gets us to about 120Vac. Add a bridge rec. and some filtering, you're at around 165VDC. That's something you can work with and get the tube to do its thing if the circuit is properly designed. The triode is a low-current application, so the high voltage side only needs to be able to supply 5-10mA total (depending on the circuit).



As for doing it on a model railroad.... It is a way to get higher voltages to remote parts of the layout, but I don't think there is a practical reason to do this. If you can get to that part of the layout to set up whatever it is that needs the power, you more than likely can run the additional 2 wires to that location as well (properly shielded and marked).

From a safety aspect, I think there is potential for some serious injury. I suspect the general assumption is that once the power hits your transformer, anything down-stream of that on the layout is low voltage (sub 50V). Having a high voltage component on the board, without an isolated and well protected supply, opens the door for injury.
 

·
Registered
Joined
·
502 Posts
BENZ SHOW & TELL

Hello Ben. Thanks for the video demonstrating the principles of using toy train transformers in various configurations. Show & Tell videos are informative for sure. After reading some of the responses on this thread. I can guess that any further videos posted from any MTF member should have a Danger Warning Disclaimer to protect the uninformed. IMO We may call these Toy Trains but in reality they are Toys that require ADULT supervision and at least a basic knowledge of the workings of Electrical/Electronic principals. Having worked in the Electrical/Electronic arena for 45 years I have learned to RESPECT not Fear electricity. Be knowledgeable of what you are doing at all times.

NOT MEANT AS A RANT JUST AN OPINION

LATER
 
1 - 14 of 14 Posts
Top