You have to be somewhat careful with voltage doublers, I forgot that when I was trying to adapt the Super-Chuffer to conventional running.  

I ran around the track a couple of times and then it let the magic smoke out!  Yep, you guessed it!  I forgot about the maximum input voltage for the switching power supply module, toasted it and the processor in a flash when I got running near full throttle.

Greg, thank you for posting the update.  Your pictured module has a 100uF input capacitor but I suspect when you augment that with 330uF you'll find you get another few tenths of a Volt of lower-voltage operation...in addition to reduced flicker/dropout tolerance.

I think most guys will simply set-it-and-forget-it, but what I've done with these modules is to mount them upside down on posts (4-40 machine screws) to gain external access to the adjustment.  Then I drill a hole so I can change brightness without opening the car.  Yes, you can't perform the adjustment "live" with the car on the track, but these modules seem to have a very uniform Volts-per-turn.  Most module use multi-turn trimpots so they are not overly sensitive meaning I don't worry that I'll overdrive the lights to 13V and pop them!

But what inquiring minds want to know is what is it that should not be forgotten?!

I had this stuff on order so I gave in it a shot and it seems to work.  Believe me

I don't understand 1/10 of what you guys get into sometimes but it does make me want to try out new things.

Over the past couple  of years this forum is where I got 75% of my information about trains and running tranis.

I'm really thankful for the help

Greg

I downloaded the specifications:

• Module property:Non-isolation buck
• Rectification mode:Non-synchronous rectifier
• Input voltage:4V-40V
• Output voltage:1.5V-33V
• Output current:Rated current is 2A,maximum 3A(Additional heatsink is required)
• Conversion efficiency:92%( highest )
• Switching frequency:65KHz
• Output ripple:30mV( maximum )
• Load regulation:±0.5%
• Voltage regulation:± 2.5%
• Work temperature:-40 ℃ - +85 ℃
• dimension:43mm*21mm*14mm(L*W*G)
• NOTE:This can't be used to step up Voltage

Package Include:

• 5 x Step Down Module LM2596

Stan, I have found after I hit 65, little notes to myself are now a part of my life.

As to that note  to "don't forget", I don't remember!!!

Greg

Dale, that's a switching power supply, so it does not use the power that a plain resistor or linear regulator would dissipate.  Typical switcher efficiencies are in the 85-95% range.  If you drop 18 volts to 12 volts at 100ma with a resistor, you dissipate .6 watts.  However, if you do the same with a 90% efficient switcher, the switcher only dissipates .06 watts.  The .5A 5V switcher I use on the Super-Chuffer barely gets warm at 18V track power and 100ma current draw.  in the same space, the LM7805 linear regulator would dissipate 1.3 watts and shoots up to around 90C in open air!

Here's the first car with the LEDs installed. I have a small O27 layout with a lot of curves so my running has to be at some what of a slow speed.

The voltage at the track was 13 volts and I set the LEDs at 9.5 volts. I let the train run for 15 or so minutes with no heating of the regulator or LEDs at all.

The baby Madison has the LEDs

Only 5 more cars to go.

Greg

That little module won't heat up at all running the LED's.