STM2 work with SuperSnap switches?

It looks at +5 to -5 volts as the signal from the FT switches. Do you know what the K Line switches output to the remote controller?

cjack posted:

It looks at +5 to -5 volts as the signal from the FT switches. Do you know what the K Line switches output to the remote controller?

I don't know if I've measured the voltage correctly.  There are five terminal posts on the SuperSnap switch.  The two on the left are for track voltage and fixed voltage.  I ignored those.  I believe that the post in the middle is the hot out to the remote controller and that the two on the right are commons out to the controller, one for thru and one for out (or the hot and common might be the other way around).

I put one lead from my meter on the middle post and the other lead on the first post to the right of the middle post, then moved the second lead to the second post to the right.  In the thru position, I got 9v and 8v; in the out position, I got 15v and 0v.  Does this make sense?  If so, what does it mean in relation to whether the STM2 can see the switch position?

Keith

Can anyone help with this?  I realize that since the STM2 was just released, nobody may have had a chance to try it with SuperSnap switches.

The output voltage measurements I got from the SuperSnap switch seem odd.  They do use LEDs rather than incandescent bulbs.  I also have Lionel tubular switches.  The output from them is 13.5v and 2.5v, and this reverses when they're thrown.

Does "+5 to -5 volts as the signal" mean that the difference between the two outputs needs to be at least 5v?

Keith

I was thinking about how to answer the question with the info about the voltage output swing from the Supersnaps. I cannot think of how to easily change the threshold sense on the STM2 to accommodate a swing of voltage all positive. The FasTrack switches put out + to - and the threshold of THRU to OUT must mean that the STM2 detects some swing of voltage of a plus few volts to minus a few volts. Shifting the voltage swing from other switches is not difficult but doing it for 16 switches is a bit much. It might be done without an active device such as a zener in series with the non FasTrack switch output, a resistor, and a negative bias voltage. That would involve a few parts for each input of the STM2, but not too costly.

Anyway, it is not compatible, but could be done by someone dedicated to the project.

Chuck, thank you.

Keith

Lionel sent me the owner's manual for the STM2 (see attached); it doesn't seem to be on their website yet.

In addition to showing how to wire the STM2 to monitor FasTrack switches, the manual shows how to wire the STM2 to monitor a Lionel tubular switch and an Atlas switch.  Lionel tubular requires 1 wire between the switch (from the thru or out terminal--not sure which) and the STM2.  Atlas requires 2 wires--1 from the thru terminal and one from the out terminal.

Does this info change the likelihood that the STM2 will work with SuperSnap switches?

Keith

Yes. Sounds like they designed it to work with other switches. In the case of the Atlas, maybe it looks at a positive voltage from the thru or the out. We need to know more, the voltages the Atlas puts out, but it sounds similar to your switches.

Just to update this thread:

Lionel told me they thought the STM2 would work with K-Line by Lionel (or K-Line) SuperSnap switches, but they hadn't tested to verify this.

I obtained an STM2, and not only does the STM2 work with SuperSnap switches, but it works with only 1 wire between the switch and the STM2 (as with FasTrack switches and with Lionel tubular switches).  (The owner's manual indicates that with Atlas switches, 2 wires are needed, 1 from the thru terminal and one from the out terminal.

By the way, the STM2 is really cool!  I'm just amazed when a switch is thrown from the CAB-2 or by the non-derailing circuit and I see the switch position indication change on the iPad.

Cheers!

Keith