AC Supply. What can I use for a throttle

yes you can use it but typically accessories use 16 vac but not always, what is the amp rating on your power supply?

Also it should either be fused or a circuit breaker in case of a short, you want the power to go off immediately, otherwise you could burn out your accessories, and if they are MTH they would have electronics boards and you would not want to burn out electrics as they get very expensive!  IMHO

Alan

20 volts is fine, but how many amps? If it's not labeled, figure about 1 amp/lb. as a starting point.

I have used 8 amp 22 volt industrial transformers for powering PM-1's for CAB-1 conventional control. It works well despite the 18 volt design of the TMCC system, but do so at your own risk.

ADCX Rob posted:

20 volts is fine, but how many amps? If it's not labeled, figure about 1 amp/lb. as a starting point.

...

As funny as that sounds, that's surprisingly close.

I'm not sure you are understanding what I would like to do.  The power supply is an LGB 50110 6 Amp AC transformer.  I need to vary the output voltage.  LGB has a throttle but it changes the AC to DC at the throttle.  

Isn't there a device that would allow me to vary the voltage coming from the LGB power supply and keep it as AC ?  

Here are two photos showing the power supply and the throttle.  As you can see, the transformer puts out AC only.  The throttle, on the right, changes the AC power to DC power for running the trains.  The items shown are the European 220 volt versions.  The USA versions are identical except they run on 110 volts and are grey.  

I think I'll just use my KW transformer.  It doesn't seem worth the effort to mess with the LGB power supply.

I can think of a couple of ways to do this, but none of them are particularly practical.  

The first is to go super old school and use a rheostat.  

You waste a lot of power as heat, but it will get the job done.  If you're looking to run accessories  at a lower voltage this might work out.  

Next, you can use a Variac:

This will vary the voltage on the input side of the transformer which will, in turn, adjust the output side.  While it will work, even a cheap/used variac costs more than just buying a CW-80 / z1000 or postwar lionel transformer.  

The third option I can think of is to use a Z-Controller or similar controller that gets input from a power brick of some sort. the Z-Controller will handle 20VAC just fine, but I'm unsure about some of the other options.  

In all above cases you'll want to add a circuit breaker of some sort.  

You can also go the 'roll your own' approach and build a voltage control with some fairly basic electronics, though it may be a bit of a complex first project.  

If you're only running lightbulbs a regular light dimmer may work as well, but it is not suitable for anything with electronics or motors.

JGL

JOHNGALTLINE gave a good rundown on alternate ideas for a throttle controller for fixed voltage output. I use a variable transformer feeding a salvaged step-down transformer on one of my layouts, which works well. I happened to have free secondhand parts on hand for that.

Another possibility uses a bank of light bulbs connected in parallel, which as a group are connected in series with the circuit through the locomotive motor. Some of the earliest electric model trains used this method without a transformer. Lights were screwed in or out of their sockets to turn them on or off. More lights connected in parallel would make the train go faster. You would have to experiment with this to get satisfactory steps of speed control. The photo shows an ancient Carlisle and Finch layout with the lamp controller setup in the inset at upper right.

I used to look for alternate throttle arrangements before I acquired a variety of regular train transformers, mostly vintage and some needing simple repairs. It's probably easier to just get a regular train transformer with variable output. Some of the older ones can be found for cheap.

Dan Padova posted:

I'm not sure you are understanding what I would like to do.  The power supply is an LGB 50110 6 Amp AC transformer.  I need to vary the output voltage.  LGB has a throttle but it changes the AC to DC at the throttle.

I understood perfectly, and now with some specific information, I will stick with using it to powering a PM-1 for CAB-1 conventional control(trains, accessories, lights, whatever you wish). The MTH Z controller will do the same thing, albeit with wires instead of wireless.

Dan Padova posted:

I have an AC supply.  It's been sitting on myself for years.

Yikes.  I'd want that off of me ASAP.    OK, understood you've found a solution with your KW.  

Hijack alert.

This being a discussion forum, if we're talking about powering accessories with a spare/unused fixed-output AC transformer, many newer accessories operate on DC input.  For example, Menards, Lemax, Miller lighting products take 4.5V DC, animated mechanisms now routinely use DC gear-motor, and accessories with digital functionality must convert Accessory AC to a lower DC voltage such as 5V DC for internal electronics.   For about $7 with free shipping from Asia (eBay 201355953452) here's an AC-to-DC converter module that can function as a low-cost DC throttle - no soldering required with its screw-terminal inputs and outputs.

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It does require a DC meter to set the output voltage.  There are variants that have a larger voltage adjustment control "knob" rather than the blue component that takes a relatively small screwdriver. 

Here's another AC-to-DC adjustable converter for under $4 free shipping from Asia (eBay 391078368935) also with screw-terminal connector for AC input and DC output.

If you're able/willing to solder wires to the input and output points, you can cut the cost in half with something like (eBay 262203041158) which runs about $3 each free shipping from Asia:

Multiple modules can be connected to one fixed-output AC transformer so adding a different DC voltage output adds just the cost of another module.  For example you might need 4.5V DC for building lights, 8V DC to get the optimal speed for spinning a wind-turbine, 12V DC to drive LED strips on a station platform, 12V DC for insulated-rail signaling relays, and so on.

I suspect in a few years, there will be a thread about how to re-purpose a surplus DC-output laptop charger or the like to convert DC back to AC to drive vibrator-motor or similar accessories that require AC input!    That will be an interesting discussion.

Nobody has suggested getting a TPC? That's what I have been using and building layouts with for years. They work great.

Supposedly the new Power Masters have all the programming that the TPC did.

While the PM-1 PowerMaster can be used as a plug-n-play standalone with the 6 amp supply and a CAB-1, a TPC requires extra equipment and cabling.