 |
||
 |
 |
 |
|
||
|
|
|
|
Go
|
New
|
Find
|
Notify
|
Tools
|
Reply
|
|
http://mouser.com/Search/Produ...252bhYSQsfo594C0A%3d
I use these. Shipping is expensive and the TVS diodes are cheap so order what you think you need. Dale H Another fine product of the Cleveland Public School system. |
||||
|
Another option is to pick up a QSI power protector.
member: TCA |
||||
|
The QSI and Scott's Odds and Ends voltage spike protectors are effective in preventing and containing spikes, but offer NO protection between the pickup rollers and the onboard electronics. ALL onboard electronics should have a re-settable circuit breaker in the tender or in the engine for FULL protection.
Art Poole |
||||
|
no longer made. MSRP was about $100. TVS from Mouser about 40 cents each. Dale H Another fine product of the Cleveland Public School system. |
||||
|
If you are good with a soldering iron, you can make your own for a fraction of the cost of a commercial one. Check out Hirailers Unlimited Click here The information is old, but still valid. Prices, if listed, are out of date. The concept is not.
Chris LVHR |
||||
|
Just want to say thank you to everyone for your help. I ordered the TVSs from Mouser and will become busy with my soldering setup.
|
||||
|
Based on the discussions on this forum, I just received some TVS diodes from Mouser to help protect my layout.
I got the ones recommended by Dale H, in his link: http://mouser.com/Search/Produ...252bhYSQsfo594C0A%3d They are described as "TVS Diodes 1500W 30.8V Bi-Directional". Does "bi-directional" mean they can be hooked up in either direction? They come packaged in a tape with one side red-tape, the other side white-tape. Is the directionality important in hooking them up across track leads? Bob Anderson |
||||
|
 |
Bob, that is correct, Bi-dir is not polarized, works in either direction.
The packaging is a standardized thing, used for polarized and non-polarized alike. Since these parts are non polarized, ignore it. Russell Russell   |
|||
|
Do you just install one per loop? Or do you put one every so many feet around each loop?
John Weber |
||||
|
 |
I work for a company that manufactures Transient Voltage Surge Supressors. I am not not an engineer, but there are a dozen smart guys at work who do nothing but worry all day about transient surges!
They sell good solid products, and they will guarantee anything you plug into it (as long as you properly wire it up). They make a great product for only $49. It's full of real circuits and will automatically cut power to the plugs if the voltage drops below 90 or rises above 140. Panamax M4-EX  If you have something plugged into their surge protector and it gets blown up by lightening or another surge they will pay for repair or replacment. Been around for 35 years. They are good folks. Please excuse the shameless commercial endorsement. |
|||
|
Once again, for FULL protection during a derailment, those transient surge devices must be installed between the pickup rollers and the electronics! Surge protection between the track and transformer will NOT protect onboard electronics during a derailment SHORT! A DIRECT short ACROSS the rails will fry the electronics before the circuit breaker on the transformer (even a Z-4000!) can cut off the current!
Art Poole |
||||
|
 |
The item Henrysdad is discussing is good for surges coming from your power lines, for example lightening strikes. I use a metal Belkin brand surge protector with 5 dual outlets, available at the large home improvement store. Plenty of places for wall warts, a big on/off switch.
As Art said, the Transients/surges thatare generated when a short occurs, and also when the short stops, a big inductive kick can occur. Personally I use 33V MOV's soldered directly to the underside of my tubular track. They were used items from where I work that could not be re-used. CKE brand ??? I think TVS are better than MOV, its just that they were available. Michael    |
|||
|
Does anyone have a drawing or picture of the TVSs installed? Do you need one for each lead in engine going to the Protosound or just one for the center rollers? I am a novice with electronics.
Paul Warning...any tinplate left at my house by visitors is fair game! |
||||
|
Hi Michael, MOV's or "Metal Oxide Veristers" I think that's right  , are pritty good the only problem with them is when they take a large hit they can pop like a fire-cracker. We use to use them in breaker panels long ago to protect computer feeds. They did the job but as I said when a surge came in they went off and scared the office people.  Keep On Tracken, Mario E. |
||||
|
I once had a short occur when a Lionel heavyweight contact roller wire had its insulation rubbed off by a wheel. In spite of the nanosecond breaker on my Z-4000 and a QSI Power Guard attached to the transformer terminals (as per instructions), I lost a board in the tender of a TMCC engine! Essentially, the short occurred between the "hot" roller wire and the ground rail, sending a significant spike DIRECTLY through the boards in the tender, since I had NO MOV or TVS device between the roller and the electronics!
 Lionel made the repair under warranty, since it was their "sloppy" wiring on the pickup roller that caused the problem in the first place. The kicker was they installed the replacement board incorrectly, and it had to make a SECOND trip to Lionel for that mistake to be corrected!  Art Poole |
||||
|
It is my understanding that the "A" at the end of the Mouser TVS part number does indeed signify "bi-directional" and that is precisely what you need for alternating current (AC) which is what the vast majority of O-gauge transformers put out.
The number in the middle (33) is used by many. There is also a (36) version which is sometimes recommended for use with old transformers, such as the old Lionel Z-type (not ZW) which could put out as much as 26 volts in normal operation. The "36" types have additional "headroom" so that the TVS does not do its thing at operating voltages. (If this is not clear, remember that there are booster voltages put out in the whistle circuits of the postwar transformers/controllers. If you have all modern [(lower voltage] equipment, the "33" type is probably adequate, maybe preferable, but since I mix-and-match postwar and modern from time to time, I personally use the "36" types.) Note: this is a fine forum and it has several folks with actual technical expertise, but it is not the only place for such info, and you can sometimes find a different perspective elsewhere. I don't understand the apparent reluctance to check out the work of Bob "lionelsoni" Nelson on the CTT forum. Compared to this forum, the CTT one has much less action, but it does have a couple of advantages regarding this and various technical questions: 1. Stuff seems to remain in the archives much longer than on this forum; 2. lionelsoni himself. He doesn't post here, and if it were not for him I probably wouldn't go there at all. I'd love to see him and some of the heavy-hitters on this forum all contribute to these technical discussions. Also, I once found some good TVS stuff on the TMCC sub-section of our OGR forum. Don't know whether it's still there. edit: added a comma. I really like commas, and keep a supply on hand, so I had one to spare. > This message has been edited. Last edited by: wolverine49, |
||||
|
Art, So when you install them between the hot rollers and the electronics, if you have a short, do these burn out and need to be replaced? |
||||
|
The way this is worded, some may think that putting the TVS in series "between the pickup rollers and the electronics" is what is being suggested. As you want to shunt a voltage spike that appears at the rollers, the TVS should be inserted in parallel with the electronics, i.e. one lead to the wire coming off the rollers, and the other lead to a convenient ground. . |
||||
|
If adding these is good practice, you would think any reasonable designer of the new electronics would include them in the manufacturing process?
|
||||
|
Thanks rail reading, yes I did misunderstand. Does any one have a circuit sketch just to clarify? and Ground you mean the chassis of the locomotive. So do you need to replace after a short?
|
||||
|
 |
I was wondering when a TVS devise "does its thing" just what that is? Some devises go open which is fine for trains I guess? You blow one in series with an engines rollers and the engine stops moving till it is replaced. But some types "clamp" or short out. If a short out type devise is used the TVS needs to go from frame [ground/common] to roller wire [hot side].
If the factories installed them on every engine this would be a Nightmare! Imagine sending back an engine to MTH because a derailment or short caused a momentary spark operating the devise to go to fail mode? This in effect "shorts out" the engines input keeping the track from powering up. Now you need to look for the offending engine so you can power up the track again. And then what? Many would send the unit back to the factory? That is why no train company uses them. It is cheaper to replace an occasional burnt board than the multitude of "failures" that would occur to the engine wether the devise clamp or go open. We used them for the first two years on new all electronic track circuit boxes to protect the $50,000 dollar cut sections on the Conrail Main Lines. While we got rich every lightning storm Conrail went broke changing the TVS devises out. After a storm we would go out for hours replacing them and clearing up failed shorted out track circuit boxes the TVS units "protected". All mostly at night on overtime! WoW!, we loved the TVS's. Two years later, 1988 we stopped using them and the boxes have been working without them just fine with an occasional board change after a storm. Billville has more wrecks than most layouts and I have not had my first engine failure yet. So what is going on that some Guys "need" this level of protection? Dismantling all the cars and engines is a big job I am not willing to do. But that is what makes this Hobby so interesting for some of us I guess. It's not a bad thing... Hey I have a Railroad to Run... Operating the NYC, CSX, PRR, and NYNH & H RR Daily ! And now the D&H! Where Trains run Often Located in Billville USA. |
|||
|
While waiting for Rail Reading's response, I'll try the second two questions. The chassis is about all there is for "ground". The second question is impossible to answer definitively without very special test equipment that most of us simply do not have. Unless the TVS diode fails spectacularly with obvious external damage, the typical user cannot know whether it is working -- but they are pretty rugged, I am told. If I had a $2000 locomotive I'd probably replace the TVS diode after a major derailment. For 35 cents (at Mouser) why not? (I bought 20 from them in my initial order because shipping is the major cost.) But I've never replaced one. My "solution" is to have several at various places on the layout, starting with the output terminals on the back of the transformer itself and proceeding to individual components such as locos, sound cars, etc. In the rare event that one goes bad, perhaps the others will still provide some protection. As I understand it, they are "transparent" to the electric circuit during normal operation, so that you can add all you want with no ill-effects. There is a school of thought that in most derailments the voltage quickly drops to zero and the current "drains" to ground. Further, TVS's are not current-sensitive devices, but rather voltage-sensitive ones, so maybe one ought to have a fuse directly adjacent to the rollers in line with the circuit board, as well as a TVS. Some technical guys that I know seem to think that in your garden-variety derailment, it is the over-voltage spikes, not any over-current, that may be generated as the loco bounces a bit* during the short-circuit process that damage the electronics. *Thereby making-breaking-making electrical contact. In the usual case, the wheels or chassis bridge the enter and outer rails. I realize that there may well be a special case where the rollers themselves contact center and outside rails, and perhaps in that special case there could be a direct jolt of current through the works, so to speak. edited: just a tad for clarity, not to change any meaning. This message has been edited. Last edited by: wolverine49, |
||||
|
 |
My personal inquiries to MTH did not come up with any definitive information, probably propritory info. As a result of all my repair experience on their equipment, I made the following assumptions: PS-1 and electronics prior to year 2000 do not have any TVS installed. TCU and PS2 after 2003 probably probably have it built into their 3V boards. AIU probably does not and require some fused or breaker protection, 5A fast blow. 2000 to 2003 is questionable. I make assumption, no! Williams does not have then or now. So in discussion with DaleH, it is just TOO SIMPLE to be sure and protect everything at 35 cents a piece. So, once again, I ordered a bunch from Mouser. Protection sought is between the Layout operation and the electronics in engines and in the TIU. My approach is the following: One on each output of the TIU, protecting the TIU. One across each of the lit lockons to the track loops, to clamp the obvious. AND one in each engine between roller and ground as I open them up for some other maintenance reason. My protection from the power company to the TIU is a Main Power Box surge protector and a triplett surge protector from outlet to layout power, the internal Z4K breaker (which works well), 10A fast blow between Z4K to TIU inputs and the internal TIU automobile fuses. All of the above so far except the Z4K internal breaker have never tripped and I live in the lightening capital of America, the suncoast of Florida. Once we understand all the positive (no negative) capability of installing TVS, we should just do it! All the best, Hugh |
|||
|
The TVS diodes that I refer to in toy-train land, area ALWAYS wired in PARALLEL with the power circuit -- NEVER in series. They sit there and do absolutely noting until they "see" (detect) an OVERVOLTAGE situation, and then they shunt the excess voltage harmlessly to ground. They do not "break" or "open" to cut-off the current the way that fuses and circuit-breakers do.
In some cases, the major manufacturers have provided all the protection on can reasonably expect, but you want to be sure you know what you have. That is why we have been trying to persuade people that you need both: most* of us face two types of problem (overcurrents AND/OR overvoltages) that require two different solutions: fuses/circuit breakers AND TVS diodes. As Harris and others have pointed out elsewhere in this forum, this is a simplification. No doubt, but it appears to be a useful one. I'm not going to enroll in Electrical Engineering college just so I can run toy trains. If inexpensive fuse/circuit-breakers AND TVS diodes aren't enough, so be it. *Those who have absolutely no electronics (circuit boards) anywhere on their layout can skip the TVS diodes, because there is nothing really vulnerable for them to protect. I do recommend wall-plug or even whole-house surge supressors, of course. But because voltage spikes can arise in lots of different areas of the house and layout I urge consideration of the up-close-and-personal stuff too. > |
||||
|
So now I am really confused. Circuits for dummys 101 here. Theoretically I have a TVS from the main plug to all transformers (that's easy). I have a TVS from transformer to track (are these wired in parellel or in series? you mean I need more than one and in multiple locations?) Then I have a tvs in every high priced locomotive from rollers to ground, and that would be every roller, and they would be wired in parallel to the chassis right?
And than I have no idea when one goes w/o a Os. scope? But the failure mode is nothing runs? Hmmm By the way what is the TMCC lionel lock on circuit protector do the one that looks like a battery house? Thanks for the help. |
||||
|
There is no power "failure mode" due to TVS failure. See Wolverine's post above.
A&Y RY[NC's Southern/N&W connector]. |
||||
|
Thanks, Dewey, as usual. You are an asset to this forum. (I hope that, coming from me, that's not the kiss of death.) The problem is that even if a TVS has failed non-visibly (the usual way) the trains will run just fine* -- they're just no longer protected from voltage spikes. That's why I use more than one on my layout, and routinely replace them every two or three hundred years. (That's another of my little jokes, folks.) I also don't buy $2,000 locomotives; but for those of you who do it might be wise to put "Replace TVS's" somewhere on your routine-maintences schedules.) * Assuming that the valiant little TVS managed to protect the loco as it gave its life doing its job. > |
||||
|
Two questions. Are they burnt out after it shunts the overload to ground? And, What effect do they have on TMCC/DCS since one signal, TMCC works on the ground side and the other, DCS on the center track positive? Joe |
||||
|
They are pretty rugged, and generally do not burn out when doing their job. But sometimes they do, and there is no easy way to tell unless they fail catastrophically (visible damage) which is rare. I don't "do" TMCC/DCS questions. Somebody? Anybody? > |
||||
|
Here's a simple way to remember where to place fuses and TVS. You put the protecting device between the source (Transformer) and the device you want to protect. So if you want to protect your TIU you would put the fuse and TVS between the transformer and TIU. If you want to protect your track and wiring you would put the fuse and TVS between the last device before the track and the track. If you want to protect your engines you put it in your engine.
Gene Anstine |
||||
|
Thanks Wolverine. I kinda suspect major DCS/TMCC interference here especially on the DCS side... Joe |
||||
|
I am going to say I doubt it. They are not doing anything until there is a voltage spike. They are an open until they see a voltage spike then they turn on and bleed it to ground. I say I doubt it instead of a definitive no only because each layout is wired differently. It would also depend on the condition of the track. If you have sparking as the loco or lighted cars are rolling down the track you already have a weak DCS signal and add to that the TVS is working everytime it sparks you will have DCS issues. TVS's have been used in computer communications for years. (In reality that is what DCS is, a very basic computer network and if wired accordingly you don't have DCS problems) Gene Anstine |
||||
|
[quote]I am going to say I doubt it. They are not doing anything until there is a voltage spike. They are an open until they see a voltage spike then they turn on and bleed it to ground[/quote
The point is what effect it will have on the TIU during the "bleed" when it send a positive signal into the negitive side of the channel... Depends on the severity of the short but since TIU's are tempermental as it is, wouldn't it be comparable to a quick damaging shot of reversed transformer power into a TIU? Joe |
||||
|
Yes "Wolverine49" it's always good to get a second perspective on any issue, but as long as we have you pop in here from time to time were cool.  Keep On Tracken, Mario E. |
||||
|
I think most of the questions that arose from my post have been answered. I don't have time, right now, to go through a check list.
I would like to add some comments about TVS devices that have been "used" and whether they should be replaced after each derailment. The types of over-voltage spikes cause by induction during a train derailment would be measured in terms of milli-seconds. The amount of current and the short time that it would flow are such that there is not alot of energy (heat) to dissapate in the TVS. If your engine or track mounted TVS gets fried from an over-voltage (say, from nuclear weapon EMD, or a direct lightning strike on your service drop), your problems with e-boards on your train engines are going to be way down on your list. Take away: If a TVS protected your electronics after a derailment, put it back on the track ready to let it do its job again. |
||||
|
 |
Just thought I'd throw this out to you guys that have DCS. The TIU already has TVS protection built in them. I had to replace a TVS that was bad on a TIU that I purchased on ebay. Here is the link to the repair I did showing the TVS inside the TIU.
http://home.roadrunner.com/~st...hoto/tiu_repair.html CSX Al Gotta' run - got a layout to build You can checkout photos, track plan of the layout and model photos & other projects at: http://home.earthlink.net/~csxal/ or hobby products at: http://www.studiozphoto.com/Millhouse.html |
|||
|
SORRY, I did not intend to mislead anyone on a "series" connection of these devices.
I was simply suggesting they be installed ONBOARD to protect the electronics. The ideal protection would be some sort of resettable breaker/interruptor in the engine or tender! How much more could that really cost?  Art Poole |
||||
|
|
|
Great info, Thanks All the best, Hugh |
|||
|
|
|
You're Welcome Hugh
CSX Al Gotta' run - got a layout to build You can checkout photos, track plan of the layout and model photos & other projects at: http://home.earthlink.net/~csxal/ or hobby products at: http://www.studiozphoto.com/Millhouse.html |
|||
|
Thanks for the tip. Seems easy enough for anyone with some electronic skills but that kind of damage/repair is exactly what I'm trying to avoid. Joe |
||||
|
Al, Did you find what else was blown on that bad channel?? Cheers, Gary |
||||
|
| View $GS_USERNAME's Public Profile |
| Add $GS_USERNAME to my Ignore List |
| View Recent Posts by $GS_USERNAME |
| Notify me of New Posts by $GS_USERNAME |
