The postwar note is a good one imo. Without a throttle, that cant ever happen.
Few folks ever complain about buying too much power. It's the other way around; and usually involves regret and more being spent in the long run.
100w is "just right" for one big draw postwar unit too. I wouldn't consider less.
So 100w or more and it should be a sine wave unit, not chopped sine.
I don't doubt someone actually told you this, but you can't just state something along the lines of "dc doubles or triples life" without some better facts to back it, and still expect folk have it be accepted as "gospel". The facts need a little more attention.
...Oops, the "box" inserted the quote a paragraph too low.... no copy/paste today either....
carsntrains posted:Like I said all of these are great options depending on what you are running. I know I am in the minority on this one because I run strictly LC, LC+, and soon LC+2.0. I am no electronics expert and that's why I have consulted with many including Lionel. The main breaking point in the LC system is the capacitor. And another weak link is the bridge rectifier. Both sigh a huge huff of relief when you run them on DC.
Id venture to say nobody else that has commented runs strictly LC equipment. So they have no choice but to run AC. If you do run only LC engines you have a choice. With no huge investment you can run your trains the way they were intended.
Jim
Keep in mind "they" will also tell you brand X is better than brand Y transformers for running brand X, though it would take a NASA scientist and some pricy equipment to tell the difference between two sine outputs at times.
If there is dc fed, half the rectifying diodes never really have to work. But the other half works just about as hard, maybe harder. There is no reverse voltage for them to block, but 2 of 4 still use up voltage and emit some heat doing it on dc. They also now lack some of the "cooling break" ac may provide as the wave reverses and volts drop to 0v for a split second (at 60hz) and then moves to the other diode set. Most diode failures involve not enough cooling/ too small an amp choice in my experience... or simply chance. So it seems to me to have a higher chance at a diode failing.
IMO you'll never use the parts your attempting to "save" with dc, while using dc, so of course the theory is "certain parts last longer". But most electronics don't "wear out" in the same sense we are used to either. Heat damage over time is the #1 issue I've seen, normally an engineering choice based on increased profit vs maintaining a bulletproof quality.
Most diodes have an "infinate" cycle life. Cap cycling life, kinda like a battery, can be chemically worn out, but is usually more about a maker, type, and some luck than anything. I have caps from the 40s still doing their jobs, but have had countless new ones die in a year.... But yea, that cap might last longer.... might...and again, on dc it isn't doing much, and if failed open(no leg to leg contact), it would still run fine on dc fed to it. A cap only smooths voltage peaks into a steadier voltage by absorbing and releasing excess energy as needed.
If the internal rectification and filtering is that weak, then that filtering seems to me to be the deep issue vs the actual supply type. (and i know it changes nothing about what is out there already and has to be dealt with "as is") Fail predictions do become more accurate with no overkill built in...hmm. I.e.; imo, omission of adequate ac filtering means "designed to fail early" for the vast majority of the O gauge crowd.
So, if it is accurate to predict twice the life or better on dc , they are designed weakly and should be avoided just as the better parts needed to work great on ac obviously were.... Think about YOUR price difference between a set of 4- 4a and 6a diodes... now between a good cap and a cheapie. You didn't likely hit anywhere $1 in total cost difference did you? Now apply wholesale costs and your looking at maybe a quarter...
I.e., something here doesn't sit right with me; be it the info, or the build itself.
(No, I don't think you made it up. I've been told total crap on the phone by a few businesses before, including the one in question... Just like my ISP, device maker, browsers, and email companies all point at each other when there is an issue.
Few companies today admit a flaw not easily found or publicised and change it.
Only better experiences can return the optimism and faith I once had in big buisnesses too 
