Don’t Burn Your Wires Or Blow Your Boosters (240)
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- Опубликовано: 27 авг 2024
- Everything can be fine with DCC until you need to add a booster to run more locos and trains on your layout. However once you break your layout into separate blocks and connect the second booster the sparks can fly if it's not done right. In this video I'll show you how you can make your power expansion safe and trouble free and keep the magic smoke where it needs to be.
Larry, thanks for this video. Another point is that a common wire should be run between all boosters according to Digitrax. In the instruction manual for the DB210+DB220, it states "All non-opto boosters should be connected to the general return via pin 4."
Yours are the only video files where I make a point of always reading through the comments. I think this reflects two things. 1. Your videos are so good in all respects, that they attract a broad range of people of informed interest. Thank you for being the agent of that interest. 2. It pertains to #1 - the comments and responses to them are often as valuable as the videos themselves. That's a compliment to both you and my fellow viewers. All of you taken together represent one of my greatest pleasures in the hobby - the willingness of model railroaders to usefully share what we've learned. Hats off to everyone!
PS: Have you ever considered a video about passenger car diaphragms? I know it doesn't fit under the heading of DCC, but your expertise and willingness to look into a wide range of subjects lead me to think you would have valuable information and observations to share if you ever took the subject up.
Absolutely fascinating topic Larry. Thank you for the detailed explanation and solutions to the problem.
Very wise video. District (block) voltage differences can be a significant detriment. This is one reason I advocate for Opto-isolated boosters and breakers and voltage trimming.
Great video Larry learned something new today👍Keep them coming
Very good information on the boosters. Thanks for sharing.
Another good reason to install a Digitrax PM42 unit. That way you have 4 power districts on one booster. Twice, I had an N Scale loco burn to the ground and I believe this was the problem. The second time, I wished I was Gomez Adams with some dynamite, I was so mad.
The PM42 is an interesting unit but has 2 faults. First it uses older technology in the form of electromechanical relays to handle shorts. Second you can only set one common trip point for all 4 blocks. I now prefer the DCC Specialties PSX boards available in combinations of 1-4 circuits, each of which can be set independently and are entirely electronic so are very fast acting.
must have been a GE locomotive, they always catch fire, real or model!
Larry good information here. Glad I do not need another booster for my layout my Blocks work great
Thank you for sharing. Enjoyed.👍👀
As I run N scale on room sized layouts I don't need more than one booster (at this point) but I see the potential issue with vehicles parked over the gap. The club uses a PSX unit as well and I use a Digitrax (can't remember the number but it gives me 4 outputs). The nice thing about these units is that they will supply all the amperage to one block if you have enough draw but of course you can't supply that amperage to all blocks at the same time.
However, the other thing I do is to put toggle switches in so I can cut power to various areas. In an engine repair yard where I have lots of short sidings, I can turn the power on and off so that I can park lots of engines and then turn off the power so they draw nothing. With the turntable, the turntable itself powers each track so I don't have to worry about any current draw. By being able to switch off power on sidings through either toggle switches or power routing turnouts, I can park locos and turn the power off so they draw nothing, leaving the available power for running locos (lighting passenger cars, FREDs etc.).
The other advantage of cutting power off is that I can't accidentally start up a loco when I don't want to, something that is pretty easy to do, especially if you are using a tablet/phone with its touch screen and have a couple of throttles up at the same time.
Interesting. Really good topic you picked up. Something that we should all be aware of. Suggestion it might be better to call the problem Voltage Differences Between Power Districts, as Blocks to me has always referred to Sections Or Blocks within a Power District or Section of rail. Thanks for sharing Larry you got me thinking over morning coffee!
I think blocks are the older term going back to DC days. Power districts as I remember came about in DCC days but they basically are the same thing. Picking a title for a RUclips video is really an art form that can make or break the success of a video. After watching a couple of videos on the subject recently I have been revising titles once a video goes live and some creators actually pre make several of the thumbnail images and swap them once it goes live just to see which one draws the most views.
@@TheDCCGuy Understood. I just find blocks districts etc can become so convoluted. No worry appreciate you try to get it sorted. Right now I'm looking for a Schematic that shows Booster, PM42 and BDL 168 all wired up. Thanks for your response
You want to look at the 1.25mm pitch micro JST. The JST you are showing also has a substantially larger gauge wire on it that the other.
I think the one I showed was 1.25 mm, I know it was the smallest I could find on ebay.
Our club layout uses 4 blocks. I was running a older HO loco that has left wheel pickup on the front truck and right wheel pickup on the rear truck it was a dc loco and would not travel accross any of the block joints. I added extra pickups to the other wheels and it works like it should. This should only happen when pickup on a loco is separate between front and back.
Very interesting! I thought that a grade crossing or rail crossing might be a good place to make the gap. Trains are not supposed too “dally” on crossings. Thanks again for your thoughts!
Very interesting thanks. I do have a Digitrax system but it seems difficult to get Digitrax supplies here in the UK sometimes.
Digitrax was heavily backordered for some time after a hurricane wiped out their facility a few years ago.From what some of my UK contacts have told me this heavily impacted their Uk sales and also set them back with the number of Digitrax owners and users.
Larry. We are fairly new to DCC. We have Digitrax DCS100 for our yard and main lower with the DB150 powering out upper mainline and storage lines. What other types and or examples of power supplies can be used with these 2 command stations other than a Digitrax PS514? I've already had 1 burn out and bought a replacement from Ebay, but there has to be a "cheaper" alternative. Great information on the different voltage between the power pack and not parking your engine over the power districts. We would have never known that. We were aware of the pertensionmeter in the command station and now I know how to use it to my advantage. I do only have an old meter tester so still have to play with that.
Thanks Larry for all you videos. Out of all the different posted you tube videos, your videos are the most descriptive and informative, right down the the basics!! I only watch the other guys just for laughs.
Cheers from Ontario, Canada
Earl
For the last few years I have been using Mean Well switching power supplies from Jameco.com . They have a myriad of voltage and amp ratings so plan to wade through page after page unless you can narrow it down by voltage. I think I covered these and gave some wiring tips in a previous video, let me dig back to see which number it is. I also showed it in the video I did on building an enclosure and installing the system on the layout. If I remember correctly for the DCS100 and DB150 you can use either AC or DC but you might as well get the DC just in case those older systems bite the dust.
OK, take a look at videos 107, 108, and 113.
@@TheDCCGuy Thanks Larry, I'll check them out. I also looked on the Jameco website and defiantly there are some options there. On another note, thanks for the information and list of CV29. I've seen that list before but it read like stereo instructions ...lol We have had a couple runaways before, one ended up with a damaging derailment of a line of tank cars.
Cheers!
Earl
Power supply != Transformer. Older hardware uses AC transformers, newer hardware uses DC switching power supplies. There's also about a volt of drop on the older Digitrax hardware made for AC transformers when using DC switching power supplies. And diode based detectors lose about 0.7v as well in detected sections.
I had an N=scale Atlas 0-8-0 that had a connector to the tender for power pick-up in the late 1960's.
And railroads have been doing it to mu locomotives even before that. So there is rarely anything new, just new ways to use old things.
When I make my 8 pin connectors, I make the connectors the same way as an extension cord: one puts the female side on the decoder side so no short can occur. Also, I use an paint pen to mark one side of the connectors so orientation is not a problem.
Larry, great video!! Tell me if I follow your logic/recommendations regarding voltage following amps. Currently, I use a DCC++EX system on an Arduino Mega. The DCC signal is routed to two Tam Valley 5-amp booster boards ... one powers OPS track ... other powers separate PROG track. I use identical but separate 16-volt supplies for the booster boards. All boards have common ground. When all is said and done, I get about 14.5 volts on the tracks.
Let's say I want to add two more blocks to the OPS track to expand my layout. I would add two more Tam Valley booster boards, one for each added block. All three booster boards would have common ground. Plastic rail joiners separating the three blocks.
Option 1: Use two more identical 16-volt supplies, one for each added booster board. All three booster boards would be powered with 16-volts but using three separate power supplies.
Option 2: Buy a large 16-volt DC power supply ... let's say with 20-amp capacity. Use the output of this single supply to drive all three booster boards.
Question: Of the two above options, which is the best?
Thanks for your attention ... all the best ... stay safe.
You need to touch base with Tamm Valley for their recommendations on supplying both boards with one power supply. It can usually be dine but may require some type of isolation or special wiring. But first let me ask do you really need 15 amps? I have a friend with a huge layout that we operate with a single 8 amp DCS240 and a bunch of circuit breakers. You might want to watch my video #112 on power management for some ideas on how you could probably get by easily with the 10 amps from 2 boosters. Although I think in that video I showed a Digitrax PM42 but now use a DCC Specialties PSX4.
Thank You Larry, an aspect of DCC I had not considered, mind I suppose you could almost deal with the Problem by creating an Insulated Block Section similar to DC Operation between the two Command Station/Booster Areas. You enter the IBS using one Command Station/Booster and using a Double Pole Switch Isolate the IBS before switching over to the other Command Station/Booster and enter the next Section, after the Train enters the new Section the IBS is insulated from the rest of the Lay-out once again. A bit cumbersome perhaps but might work? Thanks once again, trust all is well.
Larry, can I suggest that if the voltages on the blocks are different, that the input supply to the boosters is also checked and is hopefully the same. I say this because as the resident wiring guru of my local UK club, some years ago they had exactly the problem with Digitrax units, you are discussing. After checking the obvious, I looked at the input voltages and they were wildly different. The cause, the 2 transformers supplying the boosters were of different age and manufacture, one was relatively new and of good quality but the other was a salvage from previous layouts and poor quality. Although they both allegedly supplied 16V AC the older was not up to the job of supplying 5 amps.
Andy, good point. I once had a similar experience with a Digitrax PS514 switching power supply when I installed my grade crossing detector and crossing gate controller. The darned thing would not work. I tired all kinds of things then finally swapped out the PS514 with a medical grade power supply. That did the trick, there was something funky about the output that the electronics on the circuit board did not like and that PS514 was a relatively new unit. Transformers are oddities themselves but I wonder about the long term stability of switching power supplies with all their electrical components.
@@TheDCCGuy I agree, and being of the old school, I like a good old fashion heavy transformer between me and the mains supply (in my case 240v).
Thanks for this Larry. The blocks voltage difference problem is an interesting one. I imagine that if you had a faulty (or failed?) booster and were extensively using track vehicle lighting pickup etc that you could trash a lot of models in a very short time. In the case of a failed booster all the power for the dead section of the layout would be drawn through any model that bridged the gap? I wonder has anyone designed a device that constantly monitors voltage from multiple power zones and shuts everything down if there is a significant difference? I guess such a device would drop the power if there was a derail causing a short in just one section though? That could get pretty tedious.
I doubt there would be a big market for such a device as it is just easier to balance the output voltages. I have only done it once in 25 years. I have a friend who operates his huge layout with a single 8 amp DCS240 so no second booster to deal with. Most layouts can now get by with only a command station//booster.
Thanks Larry.
Larry, I think that LENZ uses the handheld to set track voltage.
Would it make any difference if the plastic rail joiners were offset an inch or so or would this just exacerbate the situation?
BTW thanks for putting the time stamp for those who wish to skip the warning part about the connectors. For me though I can benefit by the reminder to be careful. 👍
Moving the gaps won’t work as the connection would still be made across the block gaps. The best solution is to attempt to adjust the voltages and on newer Digitrax systems using the throttle makes it very easy. .
On the TCS connector can you just glue a thin piece of Styrene on top of one and do the same to the other connection, that way you can't put them together wrong. Just a suggestion.
Hi Larry
Your videos are fantastic an very helpful
If you don't mind i have a little question you regarding doing block detection on a DCC lay out that you my be able to help me with if possible?
Look forward to hearing from you
Gavin from Australia
Why not use JST connectors with silicon wiring? Would give you the same flexibel wiring, but a lot sturdier connection. Self-crimping is to a really big deal
Give me a source and a part number to look up.
Very interesting. Dont' think I've seen this subject addressed before.
I have to admit that I find it a bit disappointing that the voltage given out by your two Digitrax units is so different. Surely Digitrax could do a bit better on the quality control there?
The differences may not be their fault as I may have adjusted them in the past when doing product reviews. Plus they were manufactured several years apart. However it would be interesting to test a pair of brand new ones to see if they match but I’m not going to buy some just for that!
Wow, great topic Larry! Question 1: what is an acceptable tolerance on the voltage measurement across the districts? You mention zero-ing them out, but what if I can't achieve zero? A tenth of a volt? Two tenths? More? Question 2: Also, I assume this is measured in static conditions with nothing running, nothing drawing power from the rails. Please confirm. Question 3: Would accessories driven by track voltage affect either the measurement or the operation between districts, such as a Frog Juicer, or many Frog Juicers?
I notice that if I use the RR Ampmeter at the end of a power district, the voltage will drop as a loco nears it. So under dynamic conditions at the moment a loco reaches the break there will be a voltage difference between power districts. Apparently this isn't an issue as it is such a short time while the loco crosses over.
Thanks so much for doing these videos. They're all well-made, and most importantly, extremely helpful.
I addressed all these points either on the video or the followup comments so you might want to fead through them so I don’t have to keep repeating this stuff. That said:
1. It should be as low as you can get it and to reduce the potential for issues place block gaps in places where locos/trains won’t stop.
2. Digitrax recommends a no load adjustment. RRAmpmeters require a load for accurate measurements.
3. Yes, see #2.
Very informative. I remember seeing some reference to using a common ground, and wonder if that has any application here as you make no mention of connecting the grounds of the boosters?
Yes the grounds would be connected but to keep things simpler I dod not show that.
Thank you!
Hi Mike, how have you been? Taking advantage of the thread of conversation a little, I would like to ask you a question. I use a central DB150 and a buster DB100, both digitrax. The issue is that when the trains pass to the booster canton, they noticeably slow down. The question. How can this be regulated? Thank you so much
Can you reduce the problem of a loco (or lighted car) straddling the gap between two blocks by staggering the gaps?
Honestly I’m not sure how much they can be offset plus I always try to adjust the to the same voltage at block boundaries.
What do you mean by by having separate blocks?
WHAT LOCO PICK ONE END AND PICK OTHER END AS CROSS JOINT BOCK WITH TWO BOOSTER AS FEW BRASS LOCO SET UP?
THANK YOU FOR YOUR DETAIL VIDEO ON DCC AS SYSTEM 1 AND NCE SYSTEM USE TOGETHER LAYOUT
FROM AUSTRALIA
One of the things you advised us to do in a previous video was to run a ground wire between the two DCC units. Yet, in this video you didn't follow that practice. I'm curious as to why?
Sometimes it is simpler just to demonstrate what you are talking about and leave out extraneous stuff. However with both Digitrax and NCE you do need to connect ground wires between 2 or more command station/boosters and also some other pieces of equipment such as the PM42. As you point out I discussed this in a previous video. I actually am planning a future video on more details of using grounds with DCC.
If you use the power management idea from your video 112, does that solve this block transition issue? Or will there still be enough voltage difference to be a problem?
Since all 4 blocks are powered by a single booster it is not an issue. Only when you use 2 different boosters.
@@TheDCCGuy So the voltage output of the four device board is identical for all 4?
I have never measured the voltage of each sub district output on the PM42 but it should be the same. More importantly there will be no potential for one booster to attempt to charge the capacitors in the other to the higher voltage.
@@TheDCCGuy Thanks for replying. While you may have trusted authorities to consult, for me, you're the one.
Hi Larry, does it's feasible to use a diode bridge (signal rectifier) to measure DCC as a DC voltage?
I requires a fast acting diode circuit, standard rectifiers won’t work. So ii t really is not more a curate than using the AC setting.
The AC setting on a low cost multimeter is likely to have diminished accuracy at the approx 8kHz of the DCC signal compared to 50/60Hz household mains which it would commonly be used to measure. But, for comparing two near identical 8kHz signals from two different boosters, the error woud be the same. So, matching the two voltages would be successful even if you did not have the true voltage dispalyed on the multimeter. If you wanted to know the true voltage you could utilise a "precision rectifier", but the end result would be the same.
Roco Z21 will let you set the voltage in the app and that is going to be enforced by all Roco boosters too.
Thanks for letting me know. I hope more companies will be adding features like that in the future. I’ll have to check DecoderPrp to see if voltage settings are among the specific Digitrax features that can be changed there. I know you can change the OPSW settings there and also program the DS64 accessory decoders and routes.
@@TheDCCGuy Thank you! I checked since and have discovered the so called Light Booster doesn't have voltage match as it doesn't use the CAN bus interface. There are some very clever solutions in that system that should be implemented in other systems as well.
Great subject, even the spec sheets for the dcs200 and db150 only show the output as amps and don’t address the output voltage. Have yours ever been altered or are they set to factory specs?
I honestly don’ remember. I currently own 7 Digitrax command station/boosters including one of the first ones they made so it is difficult for me to remember which ones I might have adjusted in the past during the review process. I also do not know whether or not Digitrax adjusts theirs to a specific value at the factory. Given the number of products that have self destructed or did not work correctly when I first fired them up I am not even sure if most companies do more than random tests on the production line.
But if you get a short there at the gap. Train stop shuts down decoder then train goes till the next engine stop 5 beeps. Then continues. Now rail a&b are the same on other side now I don't have the ground wire connected to the house ground yet is this my conundrum. Or do I have to swich around bus wires. Ps let me know. I had the booster configured ass an auto reversing . Trains Never stopped on the gaps .now changed the booster back to a booster only. Now we have a short trains stop or shut down at the gap .
You have your rail a & b wires of the command station and booster crossed at the gap. Try swapping one set of wires from one of them, that was basically what your autoreversing booster was doing.
@@TheDCCGuy o.k I did the wire change over on the booster. It salved that problem. but sum layouts loop back on them self so at the other gap at the other end of the line. Now it shorts out .when it never did. Even When & well the short was happening at the other end gap . I'm thinking an nce ar 10 at that gap now. Let know if that is
So what you are now telling me is you have a reverse loop involved, which you did not include in your original question. As we have discussed in many videos anytime you have a reverse loop or other reversing situation such as a wye then you have to use an automatic reversing circuit to prevent shorts. It is a lot cheaper to use any of several auto reversing circuits to handle this than to use a booster set that way. I did a video on how to automate reverse loops so you need to watch these videos.
I have a question on a sound decoder. I was just at the Amherst Train show in Massachusetts and I purchased a Atlas 3GS21B GenSet loco with DCC and sound. When I put it on the rails, it runs great, but the lights and sounds don’t function right. The prime mover shuts down and starts up randomly when I let it sit parked. The notching sounds overlap, cut off and are very glitchy. The horn, bell and ditch lights are fine. But the front and rear headlights do not function when I push the proper button. It also is running on a 16-645E3 prime mover sound file. I have yet to take the shell off, but wanted to ask beforehand.
Since you say sound file then I assume this is a LokSound decoder? At any rate I have never seen or heard this behavior in any of my decoders. I would imagine that you will need to contact Atlas about this as I doubt the dealer can do anything about it. It may need a replacement or just reprogramming but they will be the ones to handle this as a warranty issue. I would not touch it without first contacting them.
I have a question that is unrelated to this topic. I also model the Southern Railway and am having problems finding anyone who manufactures A Southern green paint now. Do you know where I can get this?
I have been using Badger ModelFlex Southern Green for over 20 years going back to when it was Accuflex. Although it is not readily available in hobby shops you can order it through a Walthers dealer. By the way their Southern Pacific Letter Grey is a near perfect match for imitation aluminum.
Thanks for the quick reply. This color used to be easy to find but not now. I will try to order some.
@@TheDCCGuy I found a Badger Modelflex Southern Sylvan Green. Is that the one you are referring to?
Are voltage differences an issue for boosters of other DCC systems?
All DCC systems are likely based on similar electronic principles and should be equally affected. But as I said in the video ask your dealer or manufacturer when you are considering a system to buy.
Everybody is forgetting the Elephant in the room, Ohm's law. The circuitry in a DCC system flows current from a low state to a high state between rail A and rail B. The rails are always at a high voltage potential, this is know as their 'head room.' As long as the head room is close to and within the needed limits, neither block power supply is going to care at what the actual voltage between the two are at; it is just suppose to be fully energized all the time. Current can not flow backwards like that - it is the same as tying two positive battery terminals together and thinking current will flow between the two. Current can only flow in one direction from a negative potential to a positive potential across a load (Ohm's Law).
This issue does not exist in AC or DC circuits (Ohm's Law). It comes about by DCC people using terms for AC and DC circuits for what DCC is; which DCC is neither - it is digital. It is only the circuitry inside the DCC decoder that allows current to flow from a lower voltage state to a higher voltage state between rails A and B only. Until you wrap your heads around what DCC is, Ohm's Law applies.
To understand DCC you need to look at what Direct Current and Ohm's Law is. A positive potential is a pool of holes looking for electrons to fill them: and a negative potential is a pool of electrons looking for holes to fill. Holes do not go to holes, and electrons do not go to electrons; Ohm's Law states that you need a difference of potential for current (electrons) to flow. Current does not flow between two positive, or between two negative states - it just doesn't.
You can argue that with my EE advisors Larry Maier the designer of DCC Specialties products and Mark Gurries who designs electronics for Silicon Valley and is an expert on NCE products as well as DCC in general. I can forward you their emails if you so desire.
@@TheDCCGuy Job opportunity! Take a train and put it across the two blocks you set-up and see if the smoke comes out. Show me Ohm's Law is wrong. Just make a new video with a small wire jumped across the rail A between the two blocks and see if it burns up. Show me the smoke.
The current flows from the more positive terminal to the less positive terminal. When you jump start a car with a flatish battery at say 6V from a 12V battery and you have your headlights on (on either car) the headlights only receive current from the battery with the 12V charge (the 6V battery supplies no net current as it is charging). On a layout, if a wheel stops on both track gaps so linking the two blocks then the booster with the highest voltage will attempt to supply all the locos in both blocks. In practice, I expect this would cause its output voltage to drop due track, wire and internal resistance in the booster so an equilibrium is reached where both boosters supply a proportion of the current within their specified output current particularly if they are close in voltage to begin with.
👍👍👍❤❤❤🚂🚂🚂
🚂😎👍Awsum ❤️👍
Hi Guy Have Ho N Mark O L Amc Flyer
My problem with this video is you announce you're going to talk about blocks, but you spend a lot of time sort of maundering about connectors. This is amateurish. If you need to talk about connectors, put out a separate video. But it would also help if you use a script and take a course in basic writing.
Wow, with 17 subscribers, you must know a hell of a lot more than someone with 26,100 + subscribers !
@@charleymartin9422 Hey, think of the people with a million subscribers who don't know a thing.
All I can say is I think I know what MY viewers like and expect and I will continue to provide those kinds of videos to them. When you find something that works it’s a good idea to stick with it somI won’t be changing my approach.
@@TheDCCGuy Well, it looks like at least one of your viewers agreed with me.
@@TheDCCGuy I'm so glad that you took the first seven minutes and talked more about the connectors and showed how to test the DCC voltage using a meter. I was told about this method from Digitrax customer support but I didn't fully understand how to do it until you clearly demonstrated it. This is the the reason why so many people follow you like I do. Thanks so much.