# Jumpy Switches



## LCoffin (Oct 17, 2015)

I have a small layout with a total of 8 switches and am using all Digitrax DCC. I recently added "Detection" using a single BDL168. I use the LCD outputs of the BDL168 to throw my switches which are controlled by two DS64 stationary decoders.

My issue is that 3 switches seem to be getting an intermittent signal which causes these switches to jump (always in the correct direction not toggled). The thing that is unusual about my situation, ie not discussed in the instruction book, is that the switches in question are all controlled by a single BDL168 output. All switches are Pico Electrofrog with Pico snap switch motors.

Is it possible that the LCD signal is too weak to power three inputs on two different DS64's (one on one DS64 and two on the other)?


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## fcwilt (Sep 27, 2013)

Hi.

A quick check of the BDL168 docs suggests it should be able to drive three logic level inputs, assuming that is what the inputs on the DS64 devices are.

When you say "intermittent" do you mean they sometimes don't move when they should or sometimes they move when they should not?

Frederick


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## LCoffin (Oct 17, 2015)

No, they always move correctly. But then they start to "Jump" that is the switch tries to repeat the desired action. Since it is already in the correct position, it just amounts to a single chatter effect, but this might happen three or four times a minute. The effect is a lot of annoying noise.


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## fcwilt (Sep 27, 2013)

Hi,

Has this happened since you first installed the BDL168?

Does it happen when trains are not running?

Frederick


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## Mark VerMurlen (Aug 15, 2015)

I think I would start troubleshooting by disconnecting one of the 2 DS64s with the double input. This would result in the BDL168 LED occupancy output driving just a single DS64 input. If the problem goes away with that single switch, then that means the basic configuration is sound. Would you give that a try?

Mark


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## Mark VerMurlen (Aug 15, 2015)

I was reading through the DS64 manual. (I don't own them, I'm using SE8Cs instead.) I noticed that they support routes, meaning a single input will throw/close multiple switches. Have you looked at using routes so that you don't need to drive as many inputs as you currently do?

Mark


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## Lemonhawk (Sep 24, 2013)

I use routes on one of my DS64's. Was not that hard, just had to concentrate on the instructions, but it work the first try. So my small yard only has a push button for each yard spur and one push button that is use to get the mains turnout back on the main. Simple and user friendly.


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## LCoffin (Oct 17, 2015)

Thanks for the replies and suggestions. The chattering happens with/without trains moving. Strangely, I can remove the signal and the chattering continues for a second or two before stopping. I haven't given up on this yet. I have tried the one at a time suggestion to no avail. I'm going to swap decoders and see if this has any effect.


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## Mark VerMurlen (Aug 15, 2015)

I believe you said that no other blocks have this problem. So your tests suggest that its something particular to this block and block detection for it. Is there anything unusual about this block compared to all your others? Could this be due to a poor connection somewhere in this block? Does the locomotive run smoothly when its within this block?

Mark


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## LCoffin (Oct 17, 2015)

Mark, yes this only occurs on one block. I have double, triple, and checked again all wiring. The train runs smoothly through the block, no shorts, stalls etc. The only thing different from the other blocks (all of which work fine) is the use of two DS64's to control three switches. When I connect to either one of the inputs on the second DS64, the problem shows up. My next thought was to swap DS64's to see what happens. I'll let you know the result of this action. Also, another strange phenomenon is while testing I noticed that once the chattering starts, it continues for 4 or 5 beats after the control is removed. This also leads me to think it's a DS64 problem.


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## Mark VerMurlen (Aug 15, 2015)

I misunderstood your previous post then. I thought you said the chattering happens even when there's only one DS64 connected, but now you just said it works fine with only one DS64. So that definitely points to the BDL168 not being able to drive multiple DS64 inputs. So I would either configure the DS64s such that you use routes to throw/close the 3 switches with the single input or else look into using a transistor circuit to drive the 3 DS64 inputs.

Mark


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