Lionel SC2 Problem

Well, if the SC2 is too slow, I can't imagine anything you can connect to it that will make it faster!

Seems like you could have the SC-2 trigger some kind of custom one-shot circuit (maybe with a 555 timer) that would close a relay for a shorter period than the SC-2 closes its contacts.

I put a meter on the SC2 and hit the AUX1 momentarily, and the SC2 didn't change for at least 2 seconds.

What would that circuit with the 555 timer look like? Thanks

I  always found that my SC-2 performed sluggishly or erratically.

I remedied this by running an earth ground wire near it. (Just a length of stranded, copper wire that has one bare end wrapped around the water pipe in our basement.

This improved the reliability and reaction.

Also, are you using the Legacy remote to activate the SC-2? I I ask as I believe it has a "route throw rate" adjustment but that shouldn't come into play here.

@Professor Chaos posted:

Seems like you could have the SC-2 trigger some kind of custom one-shot circuit (maybe with a 555 timer) that would close a relay for a shorter period than the SC-2 closes its contacts.

If the SC2 triggers to slow, how does a SS speed it up?  Sounds like it's the initial trigger that's the issue, not the duration.

I am using a Legacy Cab 2 to activate the sc2 momentary sw. When I press Aux1 and let got go quickly the Sc2 stays closed way longer than the Aux1 button. If the Broadway Limited had a  5 second hold down of the pushbutton this would have worked out perfectly.

The ASC-2 in Accessory mode outputs a short pulse regardless of how long the key is held down. As I recall the pulse is between 1/4 and 1/2 second. It is designed for Lionel uncoupling magnets. There is a separate mode that can be programmed to provide an output as long as the Aux 1 key is pressed.

@gunrunnerjohn posted:

If the SC2 triggers to slow, how does a SS speed it up?  Sounds like it's the initial trigger that's the issue, not the duration.

Single-shot may not be the right name, and it may not be a 555, but I’m imagining a circuit that outputs a short discrete pulse upon transition of an input from high to low (or vice versa), and does not re-trigger until the same transition occurs again.

Since I am imagining someone else doing it, it seems like a very easy job.  

Of course it could be done simply with a microcontroller, but I was wondering if there's a discrete solution that would avoid needing a 5V supply.  On the other hand if you need a DC supply at all it may be just as easy to use a microcontroller.

I am not very familiar with the SC-2 by any means but I would think there would be a way to get it working to where it would trigger it but again I’m no expert. On the other hand I have a Accessory controller I developed that would take care of you in this situation. It’s not all that special it’s based from a 556 timer but I like to think it’s pretty well thought out, could be a little overkill but it would work if nothing can be done with the SC-2 drop me a email (I’m my profile) if interested

There are some circuit ideas here and here for generating a shorter pulse from a longer one.

However, they are intricate enough that if I were trying to do it, I'd just use an Arduino microcontroller to detect the SC2 signal and trigger your device for whatever time period you need. You can get small US-sourced Arduinos for $5; less from China.

Depending on how your momentary button is wired, the Arduino might be able to trigger it on its own; otherwise the Arduino could close a relay that would trigger your device.

if you have a DZ-2001 data wire driver the Arduino could even read a command over the serial line directly without involving the SC-2, but that's a little more complicated programming.

One thing about the Arduino, some of the Chinese ones won't allow you to use the Arduino IDE.  There's work-arounds, but I had one that I could never get working.

My go-to for small projects is the Pololu A-Star 328PB.  It's US-sourced and only $4.95, with more features than the comparably-sized Arduino Pro Mini.

I especially like that it has two hardware UARTS, so you can simultaneously talk to a serial device and use the debug terminal without needing software serial.

Would connecting the device switch to a different terminal on the SC2, such as for momentary track switch operation, give you a faster response time ?

Richie, I doubt would make a difference and besides I would have to program it for switches. Thanks to all  for the advice, I appreciate it.

Update: I have a Lionel OTC and was only controlling one operating track. I put my ohmmeter on the outputs of the unused side ( 1 and 2 ) and pressed AUX 2 and got a fast monetary action. I hooked it up to the Thunder and Lightning and it works like a charm. Thanks for the help.