I agree with Rob that Power Masters will not be harmed in this situation. The downside of using them is that they apparently use the same phase-control technique as the CW80, according to US patent 5749547, which seems to upset some brands of locomotives.
An alternative that is safe with any kind of transformer or “transformer” is a passive voltage-dropping device. Traditionally a resistor (rheostat) has been used for this; but they have poor voltage regulation. (The track voltage varies with the current drawn by the train.) A modern alternative with good voltage regulation is a series string of diode pairs connected in anti-parallel, which can be made easily using bridge-rectifier modules.
First off, I have trouble quoting from your comments; I know I’m not using the right technique, and I can’t find how to do it anywhere on the site. Be that as it may, tho,
Bob Nelson states:
A modern alternative with good voltage regulation is a series string of diode pairs connected in anti-parallel, which can be made easily using bridge-rectifier modules
I have no idea what is being said above, or what diodes can do for you. who has a book in which this kind of stuff is covered ,as well as Bob’s schemes for using hidden light bulbs to assist in nonrelay operation of signals. Something that might be called “post 1950 circuitry for 3 rail train operation” (if you steal my title I’ll sue ya!)
I don’t know whether it’s the “right” way, but on this forum I simply hit “Reply” to bring up the post to which I am replying, and then hit “Quote” to reproduce that post in my reply. If I only want to respond to a specific part of it, I delete what I don’t want and then note that I have quoted it only in part.
As for understanding the posts of certain hyper-educated members, it is sometimes true that if one knew enough to understand the answer, he wouldn’t have needed to ask the question in the first place. That is precisely why I repeatedly cite original Lionel source materials – especially those that are available online. Often they contain instructions and tips that were written for the train-operating public back in the '40’s or 50’s. By today’s standards, these instructions are not String Theory.* If folks would just take a little time to read them, they could then come to the forum with much better questions – and better questions tend to generate clearer answers.
*You thought I was going to say “rocket science” didn’t you?
I didn’t give the details because I have posted them so many times before. But I am always willing to describe something again if anyone asks.
The idea is to put something in series with the transformer that will reduce the voltage at the track. If it is in series with the same transformer output that is powering the track generally, there is no safety issue. The traditional thing to use is a resistor (or an adjustable resistor–a rheostat). It will drop the track voltage in proportion to the current that the train is drawing. If the train draws 3 amperes and the resistance is 1 ohm, the track voltage will drop by 3 volts. But, if the next train draws 6 amperes, the voltage will drop by 6 volts. This can be a nuisance if you’re not running the same train up and down the hills every time.
Diodes, on the other hand, have a voltage drop across them that is largely independent of the current that the train draws; so you’ll get the same result with little trains and big ones. Diodes conduct current in one direction only. So, to use them with the AC that we get from a transformer, you need to connect two of them in parallel, so that one can conduct the current in one direction and the other one in the other direction. When you connect them cathode-to-anode (striped end to unstriped end) to do this, it’s called “anti-parallel”.
One pair of diodes connected like this and put in series with the transformer output will reduce the track voltage by about half a volt. So, if you need more voltage reduction, you just make another pair and put it in series with the first pair. You string together however many pairs it takes to get the voltage drop that you want. (That is, until the train runs at the speed you want.)
This is where the bridge rectifier comes in. It has 4 diodes inside it that are already wired together in a way&n
Talking of transformer, Lionen 1015 45 watt, I found the answer but then undid wires and couldn’t remember, looked for a couple hours, still couldn’t find out whitch post went to center rail. With the posts of the transformer away from me and the slide lever near me I think the left post went to the center rail?
In response to Bob’s clear descriptioin of diode use, when you go into a Radio Shack looking for bridge rectifiers, are there ratings or capacities yiu have to look for in volts, amps, ohms, etc?
Everything they have will have a voltage rating of at least 50 volts, which is plenty for us. For a rectifier used for lights in a car, 1.4 amperes is enough. For one used with locomotives, 4 amperes or more.