John,
Thanks for the advice. I didn't quite know how the CL2 worked and I just assumed that it would magically reduce the current while keeping the output voltage the same. I can see that was wrong thinking. I was so intent on measuring the output current that I never bothered to measure the output voltage from the CL2. I think that by stacking these things with a 12v input, I started sliding myself down the ramp on your graph.
Since I got the results I wanted, it's easier to leave the circuit as is for this set of passenger cars. But I will take your advice and lose the 7812 for the next set of cars I retrofit. I run mostly TMCC so I will always have 18v on the track.
I tried the 0.1uF cap with my battery power only because they showed it in the example on the data sheet. I had a feeling it wouldn't make any difference and I was right.
Now as far as the filter cap for the rectifier, I was looking beyond flicker resistance and into the realm of "lights stay on over gaps and switches". Therefore, I decided to use a large cap (4700uF) because I had the room for it. When I had the LED strip connected directly to the 7812 (300ma), the cap kept the lights on for almost a whole second. Now with the CL2s installed (45ma), the cap keeps the lights on for 3 seconds after I shut track power off. That's cool! That's what I wanted.
I will attempt to post two pictures below, one of the original circuit, and one with the added CL2s. I hope they come out.
If you use a cap that big ,you may experience wheel arcing. Install and 18 ohm half watt in series to one of the leads if you have a problem.
I use a 7805 circuit and individual LEDs. I add 5, 1 Farad button capacitors, The lights stay on a couple minutes or more gradually fading when power is removed.
Dale H
