Kato Lightboard Flickering II

Flicker Circuit Test 2524

I seem to spend an inordinate amount of time worrying about light. First it was the layout lighting, then it was the flickering interior lights, which annoyed me when I detailed my first commuter EMU, and which I wrote about nearly two months ago when I did the original planning for a flicker-prevention circuit. Now I’m back, having built several prototypes and refined my design. I think I have a winning solution.


The circuit is much the same as before, and dead simple: a rectifier, resistor and capacitor, spliced in between the track pickups and the Kato lighting board. Soldering one of these together is painstaking work (my second prototype took about two hours), but with a bit of practice and some assembly-line work, I expect I can get this down to under an hour each. That makes adding the circuity to one train a fairly long project, perhaps spread over a couple of weeks of sporadic evening work. But it’s a manageable project, and the results justify the effort.

Below is my second prototype, ready to be tested on the track. It’s a bit oversize, as I thought I might need to add a second capacitor (the yellow box) and left room on the brass strips for that. But I didn’t, and so the next one will be more compact.

Flicker Control Demo 2521

And it works very nicely. Here’s a video showing the test run. The lead car is unmodified, and flickers badly. The second car is the one shown above, which stays lit constantly.

And there you have it, a very simple circuit, small enough to tuck out of sight, and yet quite effective. It’s taken me a couple of months of spare time to design and test it, but it was time well spent.

For more about the circuit, see my Preventing Flicker page.

== Comments copied from old system:
Sunday, November 21, 2010 - 02:53 PM
This is such an awesomely helpful post! I've read about this for some time, but the pictures really help! Thanks!

BTW...I finally figured out how to add an RSS feed from your site to mine! Great stuff! Keep it up!

Wednesday, November 24, 2010 - 02:15 AM
I tried to post a reply the other day, but it didn't take for some reason.

Glad you found the post useful.

And thanks for the RSS reference. I'm a regular reader of your site, and always find the material there interesting. My "More Links" page isn't on the home page, so it's not as obvious, but you've been on there since day one.