dc conversion for solenoid......what do I need?

[Anonymous]

I have a lionel 145 auto gate man, I remember reading somewhere
about converting it from ac to dc so the solenoid wont make the
buzzing noise. What I dont remember are the parts I need to
convert it over. I'm guessing I need some sort of a bridge rectifier.
If so, what size, and how do I wire it in?
Will this also work for other solenoid driven accessories, like the crossing
gate arm?

[brianel027]

There have been some articles on this topic in CTT over the past few years. There are wiring diagrams and other info in the Kambach book, 100 Tips For Toy Trains.

The full wave bridge rectifier is basically what you need. Though it also varies on how you want to make the gateman or crossing gate operate. If you are doing it from a button or Infared Dectector, the easiest way to do it is just use a DC current power source, like a DC train power pack.

I run my trains on DC current and operate many solenoid driven accessories and cars (like the milk car, merchandise car and barrel loader) using DC current with no probelms. I have had to make some small alterations, but mostly because using DC to the track gives me forward-reverse, but no neutal position - unless it is a mechanical e-unit that has the neutral on it. I've pulled many of the circuit boards out of my locos because I find they run much more smoothly and consistantly on DC. I call it "poor man's speed control." Buti t works fine for me.

[lionelsoni]

First of all, if you're using the accessory with an isolated control rail, or any other connection to the track voltage, you need to get a separate transformer for the DC accessory.

Get a bridge rectifier, like the Radio Shack 276-1146 (4 amperes, 50 volts). Connect the ~ terminals to the transformer. Use the + and - terminals to power your accessory. If you're using a control rail, connect one of these to the (un-isolated) outside rails, the other to one terminal of the accessory, and the other terminal of the accessory to the control rail. (It is that first connection that makes it necessary to have an isolated transformer.)

[Anonymous]

You might want to consider adding a filter cap after the bridge to make it really quiet. RS 272-1047 (1000uf @ 35v) should do the trick - or use the big mama 4500uf. Be sure to observe polarity.... and you may find you only need a 12v transformer to give you enough volts for most accessories with this setup.

Old 2037

[Anonymous]

QUOTE: Originally posted by lionelsoni

you need to get a separate transformer for the DC accessory.

Right now I'm running a couple of accessories from one
of the outputs from my V transformer, using a isolated rail track to provide a common
ground back to my transformer. I'm using my KW to power the track only for operation
of the train. If I under stand right, I can use the power from my V, along with the return (ground) from the KW to the bridge, then the bridge to the accessory?

[lionelsoni]

None of the terminals of the V should be connected to the KW nor to the track.
First V terminal---Bridge rectifier ~ terminal
Other V terminal---Bridge rectifier other ~ terminal
Bridge rectifier - terminal---Unisolated outside rails
Bridge rectifier + terminal---Accessory---Isolated outside rail