Dcc how to get power to points and signals

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kevinhammond

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9 Apr 2016
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Hi I have taken two wires from 8136501 TO the LGb 51800 which controls track power and lights in points and houses and I then tried to take the power to my other LGg 51750 to control points..Ihave power as the green led light shows but the point switches dont work on the 51750 .all I want to do is use mascots to control trains dcc and use my original LGB boxes to control points and lights ,so I don’t understand why this is so complicated surely I should be able to just take the power from first box to second box also I have two wires going to points
Yes, it should be easy provided the power supplies are compatible. I'll google the Massoth and LGB units you have. The power light might show even if the voltage
is insufficient (an LED doesn't draw much current), but that does suggest you have wired the two units properly.
 
John Russo

John Russo

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Maybe wrong, but John Russo informs that DCC AC and analogue AC are different, so you may need a standard AC power supply for your points, otherwise you may be causing damage!!
That is possible but I am not sure.

I would have to test it.

The DCC unit will supply a square wave AC to the track at around 20 Volts. That AC is used as input to the switch decoder (55025 or similar) and I believe can be used as input to the 51750. Both those units take the 20 volt AC input and convert it to a DC output to operate the Points and Signals.

For purposes of power the difference between a pure/normal sinusoidal AC and the square wave AC supplied by a DCC unit is inconsequential.

In the diagram below you see both types produce a cyclical Positive to Negative over time. The only difference is the Sinusoidal Wave is a smooth transition from Positive to Negative. The DCC Wave is abrupt, i.e Positive for some time, then immediate Negative for some time. The resulting power is virtually the same for either Wave form. The spacing horizontal between the wave heights (and lows) in the DCC wave is what is used to general the control signals (0's and 1's).









Read this link for some more explanation: DC versus DCC - Mark Gurries
 
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John Russo

John Russo

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GreyFox.

1. Get a voltmeter and test the AC voltage on the track when you turn on your Dimax 1200Z
2. Adjust the voltage output of the Dimax so that it is 18V. ( if it is a little off it will not hurt, say somewhere between 16-20 Volts.

Assuming you do that, connect the track to the input leads on the 51750 and off you go! I assume your 51750 is still wired to your Points.
If you have two 51750s you can either daisy chain them or separately connect a second on the tract or to the Dimax.
 
John Russo

John Russo

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Hi I have taken two wires from 8136501 TO the LGb 51800 which controls track power and lights in points and houses and I then tried to take the power to my other LGg 51750 to control points..Ihave power as the green led light shows but the point switches dont work on the 51750 .all I want to do is use mascots to control trains dcc and use my original LGB boxes to control points and lights ,so I don’t understand why this is so complicated surely I should be able to just take the power from first box to second box also I have two wires going to points
Can you post a picture of how you have the 51800 and 51750 connected?
 
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John Russo

John Russo

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Here is thread talking about a similar situation. (Just substitute Dimax 1200Z where they mention MTS)

LGB MTS III w/Electric Switches Help - myLargescale.com > Community > Forums

Mohammed from AllaboutLGB.com states that the DCC AC is not compatible with the 51750.

I personal question that. I have been on the phone with him and at times he admits he does not know how or why things do or do not work.

I don't have a 51750 and so I cannot test it.
 
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Greyfox

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28 Jun 2019
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GreyFox.

1. Get a voltmeter and test the AC voltage on the track when you turn on your Dimax 1200Z
2. Adjust the voltage output of the Dimax so that it is 18V. ( if it is a little off it will not hurt, say somewhere between 16-20 Volts.

Assuming you do that, connect the track to the input leads on the 51750 and off you go! I assume your 51750 is still wired to your Points.
If you have two 51750s you can either daisy chain them or separately connect a second on the tract or to the Dimax.
Ok I will try that, I have not got the to LGB connected together I did try that but it did not iike it ,before I had Masson 1200z I used Transformer and TOOK TWO wires from second terminal to power points
 
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Greyfox

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That is possible but I am not sure.

I would have to test it.

The DCC unit will supply a square wave AC to the track at around 20 Volts. That AC is used as input to the switch decoder (55025 or similar) and I believe can be used as input to the 51750. Both those units take the 20 volt AC input and convert it to a DC output to operate the Points and Signals.

For purposes of power the difference between a pure/normal sinusoidal AC and the square wave AC supplied by a DCC unit is inconsequential.

In the diagram below you see both types produce a cyclical Positive to Negative over time. The only difference is the Sinusoidal Wave is a smooth transition from Positive to Negative. The DCC Wave is abrupt, i.e Positive for some time, then immediate Negative for some time. The resulting power is virtually the same for either Wave form. The spacing horizontal between the wave heights (and lows) in the DCC wave is what is used to general the control signals (0's and 1's).









Read this link for some more explanation: DC versus DCC - Mark Gurries
This make more sense mabe I need a switch box decoder ,someone on already mentions but they said they did not know how to wire it
 
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Greyfox

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GreyFox.

1. Get a voltmeter and test the AC voltage on the track when you turn on your Dimax 1200Z
2. Adjust the voltage output of the Dimax so that it is 18V. ( if it is a little off it will not hurt, say somewhere between 16-20 Volts.

Assuming you do that, connect the track to the input leads on the 51750 and off you go! I assume your 51750 is still wired to your Points.
If you have two 51750s you can either daisy chain them or separately connect a second on the tract or to the Dimax.
I have a 55025 I purchased a while ago but did not need it on dc with transformers
 
K

kevinhammond

Registered
9 Apr 2016
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Scotland
From what you're saying, the way you've set things up seems sensible. There is probably just a simple problem.

The Massoth unit looks quite sophisticated. It can easily deliver enough power for both locos and point motors (up to 12A at 24V AC). It has variable voltage
and current outputs which might be the problem (they need to be set high enough to power your points, lights etc). DCC is just an AC power signal with a digital
control signal added.

You don't say what's powering the Massoth. The manual suggests that you need an external DC power supply. Make sure this is powerful enough
(350W according to the manual, which is pretty beefy!). I don't think the input voltage will matter (the manual says 16V-24V DC). You want to make sure
the output voltage that is shown on the display is sufficient (another poster says 18V, but it's possible that you might need a higher voltage)
and you might need to increase the output current setting as well (it might be set to 4A, which could be too little to operate the point motors,
especially if you have lights, locos etc also running off the same power source).

What you then want to do is to take wires from each of the two TRACK outputs on the multiconnector to the 51800, then connect that to the 51750
(just plug them together as usual). The 51800 will distribute AC (with a DCC signal) to the track sections, the 51750 will convert the AC to DC to switch
the points when you throw the switches on the box. I assume you've connected up the 51800 and 51750 to the track and points exactly as you used to,
so this should all be fine.

You could probably swap the order of the two LGB units if you wanted - it shouldn't make any difference.

If you're not sure whether you're getting any electrical output from any of the terminals, you can use a multimeter to check the voltage and current
from the terminals when you move the switches. That will give you an accurate reading. I often just use a "circuit tester" - basically looks like a
screwdriver with a bulb in it. If the bulb lights up, current is flowing. If the bulb is brighter more current is flowing. This can be easier than a multimeter.
Make sure it can handle 24V if you do this though. Something like this:


Hope that helps!!
 
Greg Elmassian

Greg Elmassian

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Hi I have taken two wires from 8136501 TO the LGb 51800 which controls track power and lights in points and houses and I then tried to take the power to my other LGg 51750 to control points..Ihave power as the green led light shows but the point switches dont work on the 51750 .all I want to do is use mascots to control trains dcc and use my original LGB boxes to control points and lights ,so I don’t understand why this is so complicated surely I should be able to just take the power from first box to second box also I have two wires going to points
The reason it is so complicated is simple:

1. you were asked several times to clarify, which you really did not
2. notwithstanding #1, people are not listening to you and trying to force you to use DCC to control the points/turnouts/switches, which you said you did NOT want.

So if you go back to the posts that actually asked you questions, and reply to those it would help.

  • Basically, what type of power are you feeding the system with?
  • DC or AC?
  • What voltage?
  • Does any power come out of your 51750?
  • How are you measuring voltages.

Honestly it would have been not so "complicated" if you had responded to the people trying to help sooner.

OK, so let's move forwards and solve your problem. For me to help you, I would like the answers to the 5 bullets above.

Best regards, Greg
 
John Russo

John Russo

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Greyfox, if you want to use your 51750 to switch the Points and Signals then do not introduce the 55025 into the conversation.

To use your 51750, simply give 18 volts of AC power to the power input terminals on the 51750.

If you want to try to use your 1200Z to provide the power, then connect the "Track" terminals on the 1200Z to the power input terminals on the 51750.
 
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D

Dan

Registered
28 Jan 2010
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Eastern MA
LGB points use polarized DC.
The control box (5075/51750) uses A/C input and has diodes to send DC to the epl drive (via momentary switches) and can reverse the polarity to control the direction of the motor thus driving the points in either direction.
The 5080 is just 4 of the SPST (read on-off) switch. So, one input wire goes directly to the terminals, the other input wire can be on or off.
 
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Greyfox

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As a none DCC user, reading through this it would seem the OP does NOT have the point control decoders. My understanding is either a Massoth 8156101 or LGB 55025 (others are available ;)) will need AC power in and the outlets connected to the point motors (assuming two wire), then setting up on the controller to active the motors.
Hi Jimmy you are making sense but a lot of what other say is complicating.i think the problem is I got I assume. dc 24v comes in to box 1 and into box 2 which I think should be ac to points and then every thing should work .but how to change current from 1 box to 2 box .massoth supply to i box 51800 then being plugged together output from 51800 is possible still dc so need to change this to ac then into 51750 to points .How ??? Paul’
 
JimmyB

JimmyB

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Paul, the point motors require a half-wave DC, you plug 16/18 vac into the box (51750) and out come the correct half-wave voltage, these just go straight to the point motors
 
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Greyfox

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Paul, the point motors require a half-wave DC, you plug 16/18 vac into the box (51750) and out come the correct half-wave voltage, these just go straight to the point motors
Sorry I don’t understand half wave vac
 
JimmyB

JimmyB

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Paul, it doesn't matter that you don't understand half-wave Volts AC (only one side is rectified, google it), that is what it is.
 
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Greyfox

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Paul, it doesn't matter that you don't understand half-wave Volts AC (only one side is rectified, google it), that is what it is.
Yes thank but that does not help me at all .do I need a another box or connection to change it’s all gobble de gook to me as a newbie
 
JimmyB

JimmyB

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23 Feb 2018
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Paul, just connect your mains to your 18 vac power supply, connect the 18 vac power supply to your 51750 inlet, connect your 51750 outlets to your point motors, that is it.

There is a manual on this page it is simple
 
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Greyfox

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The reason it is so complicated is simple:

1. you were asked several times to clarify, which you really did not
2. notwithstanding #1, people are not listening to you and trying to force you to use DCC to control the points/turnouts/switches, which you said you did NOT want.

So if you go back to the posts that actually asked you questions, and reply to those it would help.

  • Basically, what type of power are you feeding the system with?
  • DC or AC?
  • What voltage?
  • Does any power come out of your 51750?
  • How are you measuring voltages.

Honestly it would have been not so "complicated" if you had responded to the people trying to help sooner.

OK, so let's move forwards and solve your problem. For me to help you, I would like the answers to the 5 bullets above.

Best regards, Greg
Hi Greg it’s dc power out of massoth into 1200t into 1210z then into LGB 51800 which now I have connected to the LGB 51750 using the pins out of 51800 .so I have lights and train control using the 51800 to stop power and control lights in points and houses.then the 51750 should work my points.i have power to both boxes green lights on but the points do not work after reading more about 51750 I get the impression that the power I am sending to 51750 from 51800 is dc and should be ac as When I used a transformer I used the ac Sade to control points and all was ok .i understand everyone is trying to help but some of the terms don’t mean a thing to me Thanks paul