Author Topic: Power pack for Kato Turnouts (and 1 Atlas turnout)  (Read 467 times)

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Bart1701

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Power pack for Kato Turnouts (and 1 Atlas turnout)
« on: February 19, 2026, 11:58:53 AM »
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I have modified my staging yard to use Kato #6 turnouts in place of the Atlas turnouts I had been using. I also have 1 Atlas #4 turnout at one end of the yard. I tried to use a Kato#4 there, but that was not behaving well with my longer equipment. The Atlas one works just fine, so it needs to stay.

I used an old Tyco power pack for the AC power for the Atlas turnouts. (Photo attached)

The DC power that it puts out is for Track Only, so I am assuming this is variable voltage (?) for the locomotives and would not work for the Kato turnouts.

Any suggestions for an affordable unit that I could use for both the Kato turnouts (DC) and the one Atlas turnout (AC)?

Thanks,
Bart




mkearns

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peteski

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Re: Power pack for Kato Turnouts (and 1 Atlas turnout)
« Reply #2 on: February 19, 2026, 01:11:31 PM »
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Given that enough amperage is available for the power supply, Atlas solenoids should also throw using DC power.

I'm curious as to why the DC output did not operate the Kato machine. Did you have the speed control set for full speed?
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Bart1701

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Re: Power pack for Kato Turnouts (and 1 Atlas turnout)
« Reply #3 on: February 19, 2026, 01:20:54 PM »
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Given that enough amperage is available for the power supply, Atlas solenoids should also throw using DC power.

I'm curious as to why the DC output did not operate the Kato machine. Did you have the speed control set for full speed?

I actually did not attempt to use the DC from the current power pack. My electronics knowledge is pretty basic, and I was afraid I'd burn out a Kato turnout!

How would I be able to test it and know if it would be safe to use before actually hooking it up to a turnout?

Bart


peteski

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Re: Power pack for Kato Turnouts (and 1 Atlas turnout)
« Reply #4 on: February 19, 2026, 01:27:25 PM »
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If you have 12V bulb handy connect it to the DC output and see if it lights up.  Or if you have a lighted passenger car or a DC locomotive, thy those. If not, I wouldn't worry about burning out the Kato machine. Just briefly touch the machine's wires to the throttle terminals (with the throttle set to full speed).

Or try throwing the Atlas machine from the DC terminals.  It will probably work (or at least you should hear it try to throw).
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Maletrain

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Re: Power pack for Kato Turnouts (and 1 Atlas turnout)
« Reply #5 on: February 19, 2026, 02:51:01 PM »
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The Kato switch machines, contained within the Kato "ballast" portion of their Unitrack, are not hard to burn out if you are not using the Kato switch controls.  The Kato controls have spring-loaded contacts that quickly make and break as the lever is moved from one position to the other, no matter how fast or slow the lever is moved.  That limits the total amount of power that is provided to the coil so it won't burn out.

Using a non-momentary switch, or holding a momentary switch in the contact position for too long will burn out the coil.

That said, I have used all sorts of AC and DC wall warts to power Kato switches through that blue adapter that mkearns posted.  That isn't a supplier of power, it is just a rectifier to make sure that the power going to the turnout is DC, and uses snap-on contacts on one side for attaching to the Kato lever controllers. 

I have found that I need to use higher than 12 volts to reliably throw the 4 coils in the Kato "scissors" double crossover.  The one I settled on for my experimental layout is an old Radio Shack "Realistic" wall wart that supplies DC at 14.5 volts and is rated at 800 mA.  That does not burn out single coil Kato turnouts when used through that blue adaptor on the Kato level controls.

Bart1701

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Re: Power pack for Kato Turnouts (and 1 Atlas turnout)
« Reply #6 on: February 20, 2026, 11:33:20 AM »
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Thanks for the ideas everyone!

A few more questions and thoughts...

1) The Kato DC Converter that was mentioned looks interesting. I can't find a lot of pictures of it on the internet that show all sides of it. I assume the wires coming out of it would connect to the AC outputs from my old power pack. I am not using the Kato Switch Controllers, but will be routing everything through a control panel that uses momentary contact push buttons (Yes, I understand the issues with using these!). Is there a way to secure wires to the posts on it that snap into the Kato Switch Controllers so that I can send power to my control panel?

2) I only have 4 Kato turnouts that need to be operated. Would a wall wart that outputs DC power be another option to use to get power through my control panel? If so, what DC voltage would be needed? Would 9V DC be sufficient? I had read an article on the internet where someone said they are using a 9V battery to power the turnouts and that it is working fine for them.

Thanks,
Bart

peteski

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Re: Power pack for Kato Turnouts (and 1 Atlas turnout)
« Reply #7 on: February 20, 2026, 12:21:04 PM »
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Bart, you likely have a fresh 9V battery at home - give it a try and see if that works!
Maletrain mentioned needing for more than 12V, but he also was throwing 4 switch machines at the same time.
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Maletrain

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Re: Power pack for Kato Turnouts (and 1 Atlas turnout)
« Reply #8 on: February 20, 2026, 12:41:56 PM »
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If you are not using the Kato switch controllers, then that blue gizmo is not needed, because it just rectifies AC and provides a snap-on connection to the controllers.  If you use a wall wart that outputs DC, then just connect that to your control panel switches.

Voltage is just one part of the throw-power issue (unless you use capacitors in your control panel).  The internal resistance of the power supply will drop the voltage available as the current draw increases, and that can become a factor in whether the solenoid magnet develops enough power to move the turnout points. 

I played around with several wall warts that put out DC at various voltages with various current ratings until I found one that would reliably throw my double crossover's 4 sets of points.  You could experiment with batteries.  Just recognize that a set of 8 AAA batteries might not throw what a set of 8 D batteries will throw.  And don't be afraid to go to 10 batteries for 15 volts (open circuit voltage).

If you are only powering one turnout at a time, then a regular 9 volt battery (with the snap connectors) will throw that reliably when directly connected to the turnout's attached wired lead.  It is another matter to consider how much voltage drop there will be between your power source and a distant turnout with your control panel wiring in the circuit.

peteski

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Re: Power pack for Kato Turnouts (and 1 Atlas turnout)
« Reply #9 on: February 20, 2026, 12:49:34 PM »
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Steve, I recall there was a lengthy thread about your Kato switch machine setup and how to power it. Did you ever measure the resistance of the Kato solenoid? That would allow us to calculate what amperage is needed at 12V to reliably operate them.

Another simple calculation could also be done to determine the resistance of the connecting wires, so an appropriate wire gauge could be calculated.  And of course the power supply internal resistance (aka. its current capacity) has to be sufficient to supply enough current at the full voltage needed to power the solenoids. Also as you said, the power supply voltage would have to be chosen to compensate for the voltage drops in the wiring.
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Maletrain

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Re: Power pack for Kato Turnouts (and 1 Atlas turnout)
« Reply #10 on: February 20, 2026, 04:24:25 PM »
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Peteski, I don't think my Kato turnout powering was any significant thread here on TRW.  There have been threads by others for several approaches.

Quickly measuring the resistance between the 2 wires going into a Kato #4 turnout, I get 20.1 ohms.

But, considering that we don't really know the energy required to move the solenoid slug from one position to another, I don't see any sure way to calculate the voltage x current x duration sufficiently accurately to predict what power source is just barely adequate to throw the turnout.

That is why I suggested just trying some batteries on the actual setup.  We already know that a 9 volt battery will throw one solenoid with just a manual quick touch of the wires to the terminals.  So, first try a 9 volt battery as the power for the final control panel.  If it works, your done.  If not, try adding some D cells together or using some old DC output wall warts at increasing voltage levels until you find something that works reliably.  By starting low and working toward higher voltages, there is not much chance of burning out a coil (assuming you limit electrical contact to quick touches or button presses).

I will note that the solenoids do apparently heat up a bit and go to somewhat higher resistance if you keep throwing the turnout back and forth.  That was apparent with my 4 solenoid double crossover, which would throw all 4 the first time, but one and then 2 would not go all the way over on successive tries if I did too many too close together in time.
« Last Edit: February 20, 2026, 08:51:50 PM by Maletrain »

peteski

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Re: Power pack for Kato Turnouts (and 1 Atlas turnout)
« Reply #11 on: February 20, 2026, 11:17:45 PM »
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My point was that in order to power the solenoid to its full potential (if it is designed to operate at 12V) you would need to supply 12 / 20 = 0.6A of current. That is actually not all that much. That would guarantee that the solenoid will operate as designed.  My goal was never to determine the minimum voltage and current needed to barely operate it (because that is not a reliable  way to use it).

Of course at 9V less current will flow through the solenoid: 9 / 20 = 0.45A.  A fresh 9V alkaline Duracell battery, according to some specs online should to be able to supply up to around 4A for a very short time, and longer duration current of around 0.25A.

Using "peteski logic" seems to me that a a fresh Duracell alkaline 9V battery should be able to positively operate that solenoid.

I did not consider the resistance of the wiring, but it should be negligible (unless long feeders are made using 30AWG wires).  :D Besides, the battery will be used for a quick test, being connected directly to the switch machine's leads.
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milw156

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Re: Power pack for Kato Turnouts (and 1 Atlas turnout)
« Reply #12 on: February 25, 2026, 09:54:46 PM »
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tried the 9V earlier today (before I came across this), it will definitely throw a turnout. I only have one, so don't know how many it might handle at once, but the throw was essentially instantaneous.