Voltage drop from insufficient power source or bad connections

Well, lets do some load estimates...

Let us calculate the output wattage at ~90W for each RW (About 80% input wattage) and then calculate the load you are placing on them:

Total load:

13 switches with 2 bulbs each (lantern and controller): 13x2x5=130 Watts

5 Lockons: 5x5=25 Watts

8 Bumpers 8x5=40 Watts

Total Load: 130+25+40=195 Watts

Even if evenly split exactly, you get 97.5 Watts per transformer which is really pushing things. This combined load of 195 Watts would just about be perfect for a dedicated ZW.

Other things to consider is swapping in some direct fit replacement LEDs like those provided by vendors such as https://stores.towncountryhobbies.com/leds/ as they will draw significantly less current.

That is not to say there are not high resistance connections, and you don't indicate your wire gauge or run lengths to determine how that is contributing.

Thanks. You nailed it. I was somehow thinking 2-3W per bulb. And, while a nit, I don't have the switch controllers wired up yet. But, your math is what I have to prepare for, so it was only going to get worse for me.

I'm using 14/2 wiring and my longest run is 15-20', nothing too long. My guess is I might have a few weak connections, but that's a finer detail.

Your math made my next steps obvious.

1. Wire up the ZW.  I did that since the first post, and the voltage holds steady, but as you point out, I could easily max it out once I put an engine on that loop. My plan was 3 engines (2 on mainline, 1 in yard), so the ZW needs some relief.

2. Wire up the switches (and controllers) to a separate transformer (or two) as originally planned anyway. That'll be my project tomorrow or next weekend. Looks like I might need 2 of them to cover 130W just from the lamps. Maybe the RWs pull that duty.

3. Add toggle switches to the 5 short storage sidings with lighted bumpers. That'll save me 5*5W or 25W for much of the time. These won't have an engine stored on them, just freight cars, so I shouldn't have to worry about an engine taking off at full speed when I flip it on (due to not recognizing the DCS or TMCC signal).

4. Start buying some LEDs. Thanks so much for the link to towncountryhobbies. That's exactly what I need for the switches.

Thanks again for the assistance.

@raising4daughters I'm glad you're getting your power situation figured out.  I'm curious about the chart in the other thread you linked in the original Topic above.  Trying to follow it to that thread, it links to this one.  Could you please provide another link to that other thread with the chart you saw?

@SteveH posted:

@raising4daughters I'm glad you're getting your power situation figured out.  I'm curious about the chart in the other thread you linked in the original Topic above.  Trying to follow it to that thread, it links to this one.  Could you please provide another link to that other thread with the chart you saw?

Thanks. I copied the wrong link. Fixed it above and added it here. https://ogrforum.com/...ngs-and-efficiencies.

If you saw my other thread, my prior problem was definitely dirty track. The mainlines are fine with the LWs and RWs but in order to use those old PW transformers, I had to split each mainline. That ties up all 4 channels of a TIU without the yard powered which means a 2nd TIU or more powerful, modern transformers, or pulling my ZW away from our Christmas layout for the yard.

@raising4daughters posted:

Thanks. I copied the wrong link.

That chart has its issues as pointed out in the other thread and really adds no real value in my opinion.

Another option is to get two more LWs to replace the two RWs.  They are easy to find and relatively inexpensive and they are a high wattage single train transformer although I run two trains per loop with relay often.  Using all LWs makes operating less challenging as they operate CCW vs all other Lionel transformers CW and that is one of many reasons I have three LWs on my layout.

Take the two RWs and wire them up to the switches.  Or use one for lighting buildings or accessories etc. and one for all the switches.  Also consider taking the light bulbs out of the switches as they are constant wattage eaters.

I have 34 Marx 1590 switches without light bulbs and use one 40 watt 12ac transformer with some primary coils remove to make it a14 vac transformer.  It also operates 20 or so uncoupling tracks, some accessories and three Lionel air whistles hidden in buildings with open windows.  The key is these are all intermittent uses so the transformer does not get over worked.  I switch several paired switches with one switch for each direction and at a the same time for about 1/3 of the switches and it works just fine.

Charlie

The RW and LW are just about equivalent in power capabilities (sure, one can have aesthetic preferences). I think @raising4daughters' plan of spreading the load across the ZW and RWs in addition to using LED lighting is very sufficient for their needs.

@bmoran4 posted:

The RW and LW are just about equivalent in power capabilities (sure, one can have ascetic preferences). I think @raising4daughters' plan of spreading the load across the ZW and RWs in addition to using LED lighting is very sufficient for their needs.

I like the looks of the LW, too, but since they'll be buried under the layout, the aesthetics aren't a big advantage. And, you're right, the LW is only marginally better than the RW, 15 extra input and 5 extra output wattage.

My other option is a 2nd TIU and put the yard on it, but I'm hesitant to add a 2nd TIU. It seems to add some operating complexity, plus there are the challenges with the MTH technology's future.

I'm going to give it a go with my plethora of PW transformers, starting with the ZW and LWs for the yard and mains. That leaves me with 2 RWs, 2 1033s, 2 TWs, and 2 40W 1014s. I've also got a modern BW from a 2000 set, and a modern Williams 80W.

Worst case. I'll donate a couple of the PW transformers to my son-in-law and cousin who are getting into the hobby and buy myself another ZW or even a modern ZW.

A good inexpensive option would be a used PC power supply for the lights on switches and bumpers. 300 watts up to 750 watts for under $50, and easier switch to LEDs with the DC power in the future. Also, I have two of my three yards sharing a track block from a TIU channel. I have 22 blocks, with 12 on fixed one and 10 on fixed two, each from one handle of an MRC pure power dual. Signals are 10s every where. The one yard where I store some engines shares a short track block that works as a yard lead and part of a reversing loop.

Quick update and curve ball.  I'm going to buy two 180W bricks/powerhouses. Not that the above designs won't work, but in adding up my transformer needs, I'm going to need more.  I'm giving a couple sets to my new son-in-law and two other sets to my cousin's son to get them both started.  I'm going to give them the RWs and a couple other low output transformers rather than force them to buy their own. Paying it forward to get a couple 20- and 30-somethings into the hobby.

Quick question. I have some old powermaster cables. Do you know if I Can add banana clips to those to connect the 180W powerhouses to the TIU or do I need the specific cable from MTH like this one?  https://cttrains.com/HotcakesP...roduct-Viewer/ph-tiu

@raising4daughters adding banana plugs to the Powermaster adapter cables will work fine.  Kudos for paying it forward!

bmoran:  I'm trying to figure how a #167 controller would "use" watts, since it has 2 terminals and is in series, so it can't "consume" power.  I wonder if this just means that 5-10 watts is dissipated in the unit, in which case it wouldn't increase current draw on transformer.  There was an earlier version that had 4 terminals.  I do remember that chart; it also said the Lionel twin Pulmor F7 diesels drew 55 watts.

@RJR, if you take a look at the construction of the 167, you will see the theory of operation and how it all works including its power consumption patterns.

Last time I looked inside a #167 was in the middle of the 20th century.  My recollection is that when the whistle button was pressed, current flowed through a rectifier.  Being in series with the loco tender, it did not consume power on its own, but because it reduced the voltage going to the track, there was power dissipation.   No power draw on tracks--no power going through the #167.

Coils and rectifiers both have resistance which "use" power and convert it to heat.

RJR, at rest, the 167 has a choke in series, and you are correct, no power draw, no power consumption by the 167. However, the choke will dissipate power with relationship to the load passed through it. This is by design and when the choke is removed from the circuit it gives a voltage compensation boost when the full power of the transformer output is going through the rectifying circuitry.

@SteveH posted:

@raising4daughters adding banana plugs to the Powermaster adapter cables will work fine.  Kudos for paying it forward!

Steve, thanks. Sure, paying it forward, but I'd be lying if I said it was 100% noble.

I've got a couple older TMCC engines, and once I got some with ERR cruise and some Rail Kings with PS3, I don't want to touch anything without them. So, I boxed up 2 sets for my new son-in-law and 2 other sets for who appears to be son-in-law #2 pretty soon. Then, I'm passing along 2 of my grandfather's 6 PW sets to my cousin's son (my grandfather's great-grandson) to get him started.

So, while noble, it also clears space for me to get some longer passenger cars and maybe an LC+ engine out of the upcoming catalog.

bmoran:  Voltage boost?  I don't recall anything about the 167 in operation as well as the fact that when you pressed the whistle button, the train slowed way down.  Not a problem once the ZW came along in the early 50's.

SteveH:  I noted that, when I said they convert the current passing through into heat.  But, as bmoran agrees, there is no current flow within the 167 between hot & common.

It has been a while since I really took a deep look at the circuitry, but I recall that the choke under typical operation introduces a ~2-3V drop. When the choke is taken out of the circuit, those additional volts are diverted as a boost through the rectifier circuitry. Not as effective as the 5V compensation coils built into transformers as the train can still be slowed with the 167 (as you noted), but it would be worse without this design.

@RJR posted:

as bmoran agrees, there is no current flow within the 167 between hot & common.

Maybe I wasn't clear. Just because it is wired in series does not mean it is impossible to for the component to draw current.

@bmoran4 posted:

RJR, at rest, the 167 has a choke in series, and you are correct, no power draw, no power consumption by the 167.

The above could have been clearer: "At rest, the 167 only has a choke in series, and you are correct, with no power draw passing through it, there is no power consumption by the 167."

However, I went on to say that as soon as there is power draw (say a locomotive running on the track, or simply an illuminated car), the choke, wired in series to the load,  will dissipate additional power (as is the electronic properties of a choke)

@bmoran4 posted:

However, the choke will dissipate power with relationship to the load passed through it. This is by design and when the choke is removed from the circuit it gives a voltage compensation boost when the full power of the transformer output is going through the rectifying circuitry.

I thought I made clear that I agree that the 167 dissipates power when a load is placed upon it.  The next question would be, does pressing the whistle button add to the watts being drawn from the transformer (other than the wattage consumed by the whistle motor?  Transformer output voltage shouldn't be changing, but since the choke & rectifier add resistance, there is IR drop so the amperage drawn from the transformer should be falling.  Unfortunately, this discussion takes us away from important issues, like how many angels can dance on the head of a pin.

There is one good use for a 167.  If my office windows are open on a breezy day, it will keep papers in place on my desk.    Happy New Year, y'all, from Northern Virginia.

@RJR posted:

Unfortunately, this discussion takes us away from important issues, like how many angels can dance on the head of a pin.

Aren't you the one that derailed this thread in the first place?

NO!

A little more on the 167. I ran across the patent for it (US2243671A) which discusses its operation in excruciating detail:

https://patentimages.storage.g...883248/US2243671.pdf