Controlling blocks with a selector

[T-Lloyd]

I have a atlas layout book that also shows how to assign power to sertain block in my layout using a selector (DC) but it shows in the images 2 powers packs are needed but after reader it says nothing about the use of the 2nd power pack, it shows cab A pack connecting to the top left of the selector and then it shows cab B pack connecting with the same current to the bottom right hand corner of the selector. (also it has the common rail wire(s) connecting to each other then to the track)

can't you just use 1 power pack and connect it to both corners and i can sue my other power pack for another thing or is it nessesary? and what does it do?

[Jim Banner]

The arrangement you describe allows you to independently control two trains on one layout.  The alternative ways to control two trains on one layout are to
(1) run only one train at a time
(2) run two trains, letting one catch up to the other
(3) have two independent tracks on your layout
(4) use command control to independently control trains on the same track.

[RAM]

With DC with blocks control with selector switches and 2 power packs you can run two trains on the same track, at the same time.  one is controled with cab A and the other with cab B.  Now it would be a large layout and two people.  You would not want to try it on a 4 by 8 layout.  Clubs ran this way for years before dcc.

[Hunt]

T-Lloyd,
To repeat what Jim and RAM told you in other words.

Key --- using DC and track block wiring you are controlling a block of track defined by the length of each block.

You control the track in the block thus it is the same control for all locomotives in a block of track.  Once more, you are controlling the track --- you are not directly controlling any locomotive.

If you want to independently control more than one locomotive no matter where it is on the track or its direction of travel use a DCC system.

[T-Lloyd]

i just dont see why you need the secound power pack

[Hunt]

i just dont see why you need the secound power pack

Without a second power pack you do not need Altas Selector devices or to do the wiring as shown in the Atlas book you have.

Examine closely and trace the wires, each block of track is wired to a slide switch on an Atlas Selector electrical device.

When a Selector slide switch is moved to position B, the second power pack (B) has control of the block of track wired to that Selector slide switch, not power pack (A). Move the Selector slide switch back to position A and power pack (A) once again has control of that track block.

Still confused? Buy a DCC system and control the locomotives not blocks of track! 

[T-Lloyd]

thanks hunt, that is what i wanted to know