Conventional: controlling engines through block transitions

Trains without electronics can go across blocks as long as the voltages are close to each other. I wouldn't want to put a train in neutral while it's pickups were spanning blocks.

Don't know about modern era stuff with electronics.

Thanks C W.  That makes sense.  How this could effect electronics would be big concern.  I only have a few with electronics  of now but that'll build over time.   Any comments from the pros out there?

I have modern locos and like CW says all work well if voltage is close. Nothing damaged in 3-4 years.  I installed analog volunteers too since the z1000s I use don't show volts. . The other obvious point is phasing needs to be in sync.

Using a ZW so phasing won't be issue.  If I need another control source I have a 1033 I can use and have found how to phase it.  

If using SPST toggles to control block and siding power what would be suggested?  I see several mini toggles rated 5A 125 VAC / 2A 250V AC on Amazon and ebay which makes me think that may translate to >6 A at <20 V.  Even if I lash up two engines (layout only 10'x14')  I should have no issues.  A stall will push that higher I suppose.  Any opinions as if such switches would be okay or should I look for more current capacity?

I kind of dislike getting into these types of conversations because for every person that responds there is a different answer provided to the original questioner.  You say that you want to control two different locomotives.  In essence you aren't really,  If you move one locomotive out to where another Locomotive is running they are not being run independently.  You slow one down by lowering the voltage you will also slow the other locomotive down, so on and so forth.  You need the concept of "Cab Control".  You go on to state in your second response that you have the venerable "ZW" Transformer.  And if you need a second transformer you have a "1033" available.  I get a kick out of this misnomer of the "ZW".  The "ZW" is actually four independent Transformers in the same case.  You don't need that "Second", more appropriate "Fifth" transformer.

Cab Control

On the "ZW" you have Cabs "A", "B", "C" and "D".  I am not sure how big your loops are, but if of sufficient size, add more isolated "Blocks".  Get some SPDT switches with a "Center Off" position.  Wire one side of the SPDT Switch to, I would suggest the "A" Lug on the back of the "ZW" and the other side of the SPDT to, I suggest the "D" lug on the back of the "ZW".  There should be one "Solder Tab" left on the SPDT switch which is run of to the Section of Track that switch controls.  "Align" a number of Sections of Track, aka "Blocks" to the "A" Cab by throwing the switch for those Blocks in the correct manner. Now the locomotive in those blocks will be under control of the "A" Cab.  Lower the voltage on the "A" handle and the Locomotive in that Combined Block, Section(s) of track will slow and vice versa.  Throw other SPDT switches so that the section of track controlled by those SPDT switches are under control of Cab "D".  Raise and lower the "D" handle and the locomotive in those Sections of Track will, independently of the other Locomotive, will go faster or slower.  And for the "Center Off" position, When you park  a Locomotive in the Yard that you mention, turn the power "OFF" to that section of track and the Locomotive will sit there waiting for its next assignment.  Also as a Safety measure when a Locomotive vacates a Block, turn it "OFF" to provide a safety barrier between locomotives.

Now, this seems to be complicated.  And if you are solely running your trains, you will be busier than a one arm Paper Hanger.  This is where the real fun of Model Railroading comes in.  Invite your friends, Neighbors, etc. into your fantasy world.  Assign one as a "Dispatcher". Have him align the routes for the independent locomotives by throwing those SPDT switches correctly to keep your Locomotive under the control of the same "Cab" as the Locomotive enters and leaves Sections of Track aka "Blocks".  Got another Friend/Neighbor, Let them be another "Locomotive Engineer" controlling the other "Cab"/Locomotive.  Now your having fun and sharing your trains. 

Sorry, but I get Long winded!

Loose-Caboose posted:

The "ZW" is actually four independent Transformers in the same case.

Could you please cite your source for this tidbit, if you have one, as this is not correct.

ADCX Rob posted:

Loose-Caboose posted:

The "ZW" is actually four independent Transformers in the same case.

Could you please cite your source for this tidbit, if you have one, as this is not correct.

OK, Granted.  If I stated acts like four separate Transformers, would that be acceptable to you.  I was just trying to keep it simple.  I just did not want to get into an ancillary discussion on the inner workings of the ZW.  Just wanted to convey that the gentleman had four power sources already.

Purist!

Loose-Caboose posted:

OK, Granted.  If I stated acts like four separate Transformers, would that be acceptable to you.

Well, no, because the fact that the ZW is not 4 separate transformers and does not act like 4 separate transformers is very important when planning out power districts as posed by the OP.

Using multiple separate transformers to power adjoining blocks still poses some of the issues that Cab Control addresses, but not the most important one regarding the unprotected fault current across the windings of a postwar conventional transformer like the ZW.  Using separate transformers eliminates this potentially damaging internal fault current while still posing a significant potential for spikes and overloads with the voltage difference.

romiller49 posted:

Buy a older ZW and do it the old fashioned way. They are reasonably priced now.

Rod Miller

Scotie posted:

One way to achieve this with a ZW or two separate transformers with variable output would be to make a separately powered block out of the down grade. Then adjust the "other" transformer to get the desired speed.

jim pastorius posted:

Make it simple:  A transformer with 2 or more outputs, use a common ground and have the down grade a separate block and lower the voltage accordingly-based on engine, size of train and what speed you want.

George S posted:

I think I understand. I am a little slow. One handle for the uphill and the other handle for the downhill on a separate block. Why don't you guys just say what you mean?

Dan Padova posted:

So, using the single transformer method, like a ZW, the section of track on the down grade would be insulated from the rest of the layout.  Let's say that binding post A is used for the majority of the track and binding post D for the down grade.  

Does that sound like I am on the right track ?

 These methods, used for decades+, cause large (30+ amps at 6-7 volts difference on a ZW) fault currents - direct short circuits - across the transformer windings with absolutely no internal circuit protection when the blocks are bridged by center rail rollers of locomotives & rolling stock as described by Kirk.

THE BOTTOM LINE:  for true Block control.  You must have 1 SPDT electrical toggle/switch for EACH individual Block.  Atlas makes a SELECTOR that has 4 SPDT toggles on one panel.  You MUST manually adjust a particular Block Switch to the transformer that is controlling a specific engine, either transformer "A" or transformer "B".  This is the old fashion method of train control conventional.

By doing this, very easy to do, one may maintain individual control over an engine and there are no worries.  You simple keep the same engine on the same transformer.

EASY

Back in the 1950s, I had essentially a 2-loop layout.  One loop had grades.  I wanted two-way operation, and didn't want to keep playing with the transformer handle controlling that loop. 

I unwound a wire, to get single strands.  These I wrapped around a frame, making a resistor, and inserted into the leads that fed the blocks of the upper & lower levels.  I made a second, with a longer wire, for more resistance, and inserted this into the leads that fed the blocks of the grades.  Then I took a SPDT switch, and fed power directly from the transformer to it to the grades.  With the switch thrown one way, I had full power to one grade and low power to the other; thrown the other way, the other grade got full power.

System worked great.  In time, the fine wires would oxidize, get brittle, and fail (shorts accelerated the process), but it was easy to unwind another strand and replace them.

I did not use standard resistors because of the concentration of heat in the event of a short, and the fact that high wattage, low ohm resistors were out of my price range.

I did learn to break a layout up into many blocks, each with a toggle switch, to facilitate control of multiple locos.

My current layout is DCS, with 70 toggle switched blocks, using 6 TIU channels, and 3 transformers.

ADCX Rob posted:

Loose-Caboose posted:

OK, Granted.  If I stated acts like four separate Transformers, would that be acceptable to you.

Well, no, because the fact that the ZW is not 4 separate transformers and does not act like 4 separate transformers is very important when planning out power districts as posed by the OP.

Using multiple separate transformers to power adjoining blocks still poses some of the issues that Cab Control addresses, but not the most important one regarding the unprotected fault current across the windings of a postwar conventional transformer like the ZW.  Using separate transformers eliminates this potentially damaging internal fault current while still posing a significant potential for spikes and overloads with the voltage difference.

romiller49 posted:

Buy a older ZW and do it the old fashioned way. They are reasonably priced now.

Rod Miller

Scotie posted:

One way to achieve this with a ZW or two separate transformers with variable output would be to make a separately powered block out of the down grade. Then adjust the "other" transformer to get the desired speed.

jim pastorius posted:

Make it simple:  A transformer with 2 or more outputs, use a common ground and have the down grade a separate block and lower the voltage accordingly-based on engine, size of train and what speed you want.

George S posted:

I think I understand. I am a little slow. One handle for the uphill and the other handle for the downhill on a separate block. Why don't you guys just say what you mean?

Dan Padova posted:

So, using the single transformer method, like a ZW, the section of track on the down grade would be insulated from the rest of the layout.  Let's say that binding post A is used for the majority of the track and binding post D for the down grade.  

Does that sound like I am on the right track ?

 These methods, used for decades+, cause large (30+ amps at 6-7 volts difference on a ZW) fault currents - direct short circuits - across the transformer windings with absolutely no internal circuit protection when the blocks are bridged by center rail rollers of locomotives & rolling stock as described by Kirk.

Rob,

I am building a new layout and planned on using block control with zw A on one side of the switch and zw D on the other. What can I do do prevent shorting out my transformer? I guess I could buy 2 but that kind of defeats the purpose of having a multi controller transformer. If this topic is too much for a forum and you are able to recommend a book on the subject I appreciate the advice.

Thank you,

Mike

Guitarmike posted:

Rob,

I am building a new layout and planned on using block control with zw A on one side of the switch and zw D on the other. What can I do do prevent shorting out my transformer? I guess I could buy 2 but that kind of defeats the purpose of having a multi controller transformer. If this topic is too much for a forum and you are able to recommend a book on the subject I appreciate the advice.

Thank you,

Mike

If you are traveling from one block/district on 1 handle to another on the same ZW, you really need to keep both handles within 4 volts or about two windings on the secondary tap. Never park a train or a piece of rolling stock across a block delineation.  One throttle at "off" is better than one low & one high. This is how I have always done it for almost 50 years, many others do the same thing.

I have measured the fault current on a ZW, and it is negligible at 2-5 volts but quickly rises to 15-30+ amps pegging the meter when the throttles are set 6-7 volts apart... this is the type of current that is causing the burnt wires between the collector rollers in the Polar Express and similar passenger cars & illuminated rolling stock.

Ok, I get it. I`ve run conventional block control before and never had any problems, I do not see myself handing of trains from one side to the other, usually it is one controller per train. 

Thank you,

Mike

Hey guys.  Great to hear all the good feedback!