# wiring LGB 1210 switch drive?



## ThinkerT (Jan 2, 2008)

Normally, I go with manual switch drives.

But, via a quirk, I ended up with a few LGB 1210 switch drives, figured 'why not?' They work - I hooked an old transformer up to them, reversed the polarity, and the frogs moved. Reversed it again, and they moved the other way. Shut the transformer down within seconds of each test to avoid issues.

What I'm trying to do now is get them to work without polarity reversal through the transformer. 

I have several momentary push buttons. Each switch has two terminals, one red, the other white. I have 16 volt power source and plenty of wire. What I can't figure out is the circuit diagram. (Now that I think about it, I also have a few single and double throw toggle switches.)

I get the feeling I'm missing something real obvious.


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## East Broad Top (Dec 29, 2007)

If you've got momentary center-off DPDT switches you're set. 

Here's a diagram I found on the net:










Hope that helps.

If your DPDT switches are not momentary, you can add a pushbutton into the circuit between the power supply and the DPDT switch. Select the direction via the switch, then push the button to activate the points.

Later,

K


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## ThinkerT (Jan 2, 2008)

Thank you. 

My double throw toggle switches are not momentary, but combined with the push buttons...or I might just drop a few dollars at the store. (I only have three of these switch drives, and two will be on the same circuit - switches between loops.)


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## Greg Elmassian (Jan 3, 2008)

the right switches are cheap, look around probably buck and a half can be done.

Greg 897


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## ThinkerT (Jan 2, 2008)

Greg Elmassian said:


> the right switches are cheap, look around probably buck and a half can be done.
> 
> Greg 897


 I found some on EBAY for a few bucks each. 

Went and tested EBT's plan, that worked. (Thanks!)

I guess I can use the push buttons for the other switch drive I acquired as part of a job lot - a rather ornate one by Lionel. That one has four terminals to hook wires into. 

(Yes, I have been going through the piles of stuff from ages past during this layout rebuild.)


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## Dan Pierce (Jan 2, 2008)

I used AC power and 2 diodes via a SPDT switch to operate my switches. Simplier wiring, and I fed the common lead to the drive and tied the diodes (one reversed from the other). Only used 2 diodes total to operate all switches.


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## krs (Feb 29, 2008)

The schematic of Dan's set up.
(from Marteen's website)


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## Greg Elmassian (Jan 3, 2008)

Dunno Dan, a momentary dpdt switch an no diodes sure seems to be less wiring that a switch and 2 diodes that could be installed backwards.

I'd call it a wash in the best case for your idea. But a higher voltage pulsed AC has shown to be more effective than steady state DC.

Greg


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## krs (Feb 29, 2008)

The key thing to remember is that these EPL switch drives were never intended to be operated by "pure" DC.
The "normal" way to operate these is with half-wave rectified 18 VAC - that way the power can stay applied continuously if that should happen, either becaure the momentary button gets stuck somehow or if one uses a reed tripped by a loco magnet and the loco ends up stopped over the reed.
Half-wave rectified 18 VAC however is not always enough to throw the switch reliably especially if the run from controller to switch drive is long or the switch itself operates a bit sluggishly.
So charging up a capacitor to a higher voltage and then using that to throw the switch is a more reliable way.
If a DCC switch decoder is used to operate the drive using DC then LGB recommends that the DC pulse be set to about 1 second,
If one applies 24 VDC to an LGB switch drive for 5 seconds or more one risks the chance of burning out the drive. The newer LGB drives are a bit less prone to burn out that the older version, but why take the chance.

Knut


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## toddalin (Jan 4, 2008)

The method using the diodes is the method used by LGB primarily for the reasons listed.

But there is another reason for it.

If you go to automate your system of turnouts so that a turnout may _*easily*_ be thrown by any number of methods including reed switchs, several switches from your control panel (to throw groups of turnouts simultaneously), and a localized toggle, you will find that this method makes it far easier to wire up.

Also, if you want to have a single toggle throw multiple/groups of turnouts, you can do a diode matrix. Try that with dpdts. 

Also, if you want to run a few turnouts, the cost of two diodes is typically less than several dpdt as opposed to several spdt toggles. A pair of capacitors wired with the diodes can take case of any issues caused by the lower a/c voltage and will bleed down to prevent damage if a toggle is held/stuck open to power the turnout motor.

Oh, and you can use one of your rails as a common ground and save half the wire to your turnouts. With the cost of copper wire today, this alone make the use of the diodes far more economical.

And it need not end there. If you use a common rail, you will save *~half* on *ALL* of your wiring because one of the rails serves this purpose! I run three Train Engineers, the half-wave ground for my 21 turnouts, the a/c ground from my accessories and sound effects, and the a/c ground for all of my lighting that uses a 16 amp transformer in my garage *ALL THROUGH THE SAME RAIL*! That rail is represented by the kacki line in KRS's drawings. The cost of wire adds up *BIG TIME*!


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## ThinkerT (Jan 2, 2008)

Thank you all for the advice. As stated though, my preference is for manual switch drives. I just happened to acquire a few automated ones by accident.


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## KaraPelosi (Jan 26, 2021)

Hi....I don't have any close to home involvement in LGB turnouts, yet my agreement is they use DC rather than AC and you control the turnout toss by switching the extremity of the beat, a similar way Kato turnouts are controlled. Assuming this is the case, at that point you should utilize a DC power supply, or you can utilize AC with guiding diodes. There are a few different ways to control the this sort of turnout, yet I'm simply taking a brief break at work and truly don't have the opportunity to experience them. I'm certain there are strings on here about Kato turnout control, or on the off chance that you start another string getting some information about Kato turnout control you'll presumably get a few reactions.


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## krs (Feb 29, 2008)

This is a 3 1/2 year old thread, but as far as using DC is oncerned


KaraPelosi said:


> Hi....I don't have any close to home involvement in LGB turnouts, yet my agreement is they use DC rather than AC......


...the important thing to remember is that the LGB turnouts don't have a limit switch an if you apply DC for any length of time, the coil will burn out. Older models are more susceptible to that than the newer ones.
The LGB DCC switch controller limits the DC (rectified DCC) pulse to one second.


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## Greg Elmassian (Jan 3, 2008)

They do not use DC, or AC, they use a Pulsed DC, with a sinusoidal wave shape.... half wave rectified 60Hz AC....

the "pulse" helps move the turnout better than steady state DC, and avoids heating... mind KRS's post well...

by the way, I did not know the LGB controller has a timer in it, interesting, I've never heard that stated, so people using a momentary on their own need to remember that.

Greg


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## krs (Feb 29, 2008)

The preset pulse duration of the LGB DCC decoder for the switch drive varies a bit for different types of deoders.
On the LGB 55024 it's set to 800 msec.


http://www.gbdb.info/data/manual/LGB/55024.pdf


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## krs (Feb 29, 2008)

Another comment about powering the LGB switch drive.
All the "normal" circuits to control that LGB switch drive, either directly via various toggle switch arrangements or magnet triggered reeds or some sort of capacitive discharge have the same limitation when it comes to the length of wire that can be used between the actuating mechanism and the switch drive.
When that wire becomes too long, ie resistance is too high, the switch will not throw reliably or at all.

Attached is an interesting alternative - it uses a SPDT (not momentary) switch as the control and a non-polarized capacitor at the switch drive location.
I did a bit of experimenting with that circuit years ago and the wire resistance between the SPDT switch and the switch drive could be increased to about 100 ohms before the switch would fail to reliably throw.
This arrangement might come in handy for a larger layout.


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## Greg Elmassian (Jan 3, 2008)

nice and simple... just to clarify for those who might be confused, the connection of 2 electrolytic (polarized) capacitors in series (plus to plus or minus to minus) is the equivalent of a non-polarized capacitor.

KRS, would you mention the value of the capacitors used? clearly the voltage rating should be like 36 volts (you never run a capacitor at the rated voltage)

greg


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## Dan Pierce (Jan 2, 2008)

Note the 'training dutchman ' has many diagrams for older LGB units. Also the LGB 559 pdf has diagrams using all LGB controls and can be downloaded.


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## krs (Feb 29, 2008)

Greg Elmassian said:


> KRS, would you mention the value of the capacitors used? clearly the voltage rating should be like 36 volts (you never run a capacitor at the rated voltage)


I think I probably used two 1000uf/35 volt electrolytics since that is what I had readily available.
I was more interested in how much resistance I could add between the actuator and the switch drive and still have the switch throw reliably.


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## RobertHuffman60 (Dec 13, 2020)

Thank you all for the advice.


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