Cisco Kid Do you mean that simple derailments and trucks causing shorts now and then warrant systems of bulbs and or circuit breakers?
Do you mean that simple derailments and trucks causing shorts now and then warrant systems of bulbs and or circuit breakers?
Cisco,
You already have a all the protection you need in the DCC system that you have. The booster has a circuit breaker built in to keep your decoders from frying. The quarter test is make sure that the current flow through your layout wiring is sufficient to trip the booster circuit breaker before anything would fry.
The 1156 bulb idea is a modification designed to enhance performance of the DCC system in regards to shorts. The 1156 modification is in not necessary to in order to operate your system safely. Some of us question whether this particular modification is worth the effort.
Randy, I do intend to break my layout up into very large blocks with kill switches just so that I can track down shorts when they happen. So far, I have been lucky. There will be a day when I have to pull out the nippers and cut apart the buss to find a pesky short.
Guy
see stuff at: the Willoughby Line Site
Cisco Kid Guys, this is the OP again. Thanks for the tips, and no, I wasn't going to forego feeders, just wondering if soldered sections could eliminate some, and it seems true. However, you are on to a tangent here that worries me.
Guys, this is the OP again.
Thanks for the tips, and no, I wasn't going to forego feeders, just wondering if soldered sections could eliminate some, and it seems true.
However, you are on to a tangent here that worries me.
As our much liked club president would say, "Don't Panic!"
Burning out decoders:
Burning out decoders is a rarity unless you are pulling too much current through them or way overvolt them.
Turnouts that melt due to a wheel hitting the wrong throw leg or frog are not DCC friendly or you wired it up wrong.
The main point of breakers is to protect the boosters. Secondary is protecting your decoders. But it is RARE that an over current will fry a decoder. More likely an overvolt will fry a decoder first.
Multiple power districts with breakers for each are designed to 1) Keep the entire layout from shutting down due to a short and 2) Limit the current (total amps) in a given section.
HOWEVER:
Let's say you have track A and track B. Track A and B have an insulated rail joiner between them. Track A wasn't hooked up with proper feeders. As a result it reads 8 DCC volts. Track B was wired up properly with numerous feeders. It has 14.4 DCC volts. Voltage will always travel from high potential to low potential. 14.4-8 = 6.4 volts. If you have a 5 amp booster 5 amps * 6.4 volts = 32 watts. Now imagine you have an all wheel pickup train that is crossing from A to B. Guess what happens? Yep you send 32 watts from the one truck to the next. And loco wires are thin. They will burn out QUICK!
This is what happened to Cuda Ken.
Don - Specializing in layout DC->DCC conversions
Modeling C&O transition era and steel industries There's Nothing Like Big Steam!
Well that and Ken had an 8 amp booster and far too thin a bus wire, so he could get 7 amps flowing through a derailed loco without tripping the breaker in the 8 amp booster he was using. Once he had that cleared up he was actually ok but lost faith in the MRC booster so he switch to a Digitrax 5 amp system.
The quarter test would have proved that out - it sounds silly but it really does work - LAY the quarter (or equivalent if not int he US) on the rails. Do NOT press down, just lay it there - the booster or circuit breaker shoudl trip. If not, it's not going to trip when your train derails either. The reason it fails to trip is usually inadequate wiring. Too thin a bus wire, not enough feeders, bad rail joiners - these introduce resistance in the circuit and if there's enough resistance in the wires, an otehrwise dead short across the rails becomes enough of a resistor that the current flow does not exceed the booster's ability.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Assuming that you have a good DCC system with a built in circuit breaker and no more than a 5 amp booster per power district, isn't the moral of the story that you should have adequate feeders abd properly sized feeder wires to every section of track as verified by the quarter test and forget about wiring in 1156 bulbs?
Rich
Alton Junction
richhotrain Assuming that you have a good DCC system with a built in circuit breaker and no more than a 5 amp booster per power district, isn't the moral of the story that you should have adequate feeders abd properly sized feeder wires to every section of track as verified by the quarter test and forget about wiring in 1156 bulbs? Rich
In my humble opinion there is nothing wrong with 1156 bulbs. Do I use them? No. I like tony's PSX breakers. But its a matter of personal preference. A 1156 will limit you to about 2 amps. Lets say you wire up a turnout wrong, and are shorting through the points, then the 1156 will light up. But in the mean time you are sending ~25->30Watts through the points and rail. Anything that can't handle that kind of power will melt. The thinnest point in your circuit path is what will go up first.
Rich,
Your thinking is correct. But then you were told that on the NCE Yahoo group by a real live EE. Not just by us DCC users that have only experience with it and no degree.
Martin Myers
richhotrain ... Sounds like I shouldn't bother with the 1156 bulb. Given adequate feeder wires throughout the layout, my command station should shut down in the event of a short. Agree? Rich
... Sounds like I shouldn't bother with the 1156 bulb. Given adequate feeder wires throughout the layout, my command station should shut down in the event of a short. Agree?
Rich, the bulbs serve three potential benefits:
1. They provide a quick indication when they glow as to which area of an electrically partitioned layout is experiencing the fault. If you have two trains in different parts of your layout that stop suddenly, which has the fault?
2. They filter, or limit really, the amount of amperage that can course through the wires in the area affected. This effectively limits the potential damage to a decoder that you can't get to quickly. Especially an expensive sound decoder;
3. But, in providing the benefit above, it also prevents the shorts detection circuitry from tripping. On layouts with multiple users and only one base station, the base station will suspend power to the layout entirely if it detects a short anywhere. The light bulb reduces the spike to the point where the base station's parameters can include that quick burst of power as if you had just taken a long ABBA set, each with sound, out of mute status and began to tow a long train with them. So, even if you are by yourself, and have multiple things going on on your layout, the bulb will draw power severely in the affected area, glow, give you the quick indication as to the place of the fault, and the rest of your layout, say a fast moving passenger train on a closed loop, will continue apace.
No, they absolutely are not essential, and probably not very desirable in many instances. But they make my life easier, and Joe Fugate seems to like them.
Crandell
Cisco Kid I have always used a drop feeder about every three feet and at both ends of switches. However on my new expansion I have soldered most of the additional mainline (but not the switches). Just tried a few trial runs of the first 100 feet of mainline with no feeders installed yet. Of course it runs and seems to have no weak spots or voltage drops. I still plan to put in some feeders, but do I need as many as I used on my old section?
I have always used a drop feeder about every three feet and at both ends of switches. However on my new expansion I have soldered most of the additional mainline (but not the switches).
Just tried a few trial runs of the first 100 feet of mainline with no feeders installed yet. Of course it runs and seems to have no weak spots or voltage drops. I still plan to put in some feeders, but do I need as many as I used on my old section?
1. The one huge advantage brass track had over nickel-silver was its electrical conductivity (electrical conductivity/resistance list Conductivity Periodic table Sorry, I had one much easier to read and made just for model railroaders but have lost the link). Since we use nickel-silver track we need the many feeds of the nice copper wires to carry the electricity much more efficiently around and to the rail instead of through the rail. Also remember that one set of feeds every three feet means the locomotive is never more than 1.5 feet from power. I put feeds every 6 feet which gives me a 3 feet away from power number. Notice that also equates to every other set of joiners between two pieces of flex track.
2. Good tight rail joiners work great when track is first assembled. So testing on new track is sort of meaningless. One solders rail joiners to keep those those nickel-silver to nickel-silver connections nice and tight in first-assembled condition through time. The electricity is still flowing through the track and joiner not through the solder. Hopefully one is not using solder to "make the connection" on old re-used sloppy fitting joiners. Lead/tin solder is a horrible conductor of electricity. Never re-use rail joiners.
P.S. I'm in the "not soldering" rail joiners camp, except for curves using flex or hand laid track.
selector richhotrain: ... Sounds like I shouldn't bother with the 1156 bulb. Given adequate feeder wires throughout the layout, my command station should shut down in the event of a short. Agree? Rich Rich, the bulbs serve three potential benefits: 1. They provide a quick indication when they glow as to which area of an electrically partitioned layout is experiencing the fault. If you have two trains in different parts of your layout that stop suddenly, which has the fault? 2. They filter, or limit really, the amount of amperage that can course through the wires in the area affected. This effectively limits the potential damage to a decoder that you can't get to quickly. Especially an expensive sound decoder; 3. But, in providing the benefit above, it also prevents the shorts detection circuitry from tripping. On layouts with multiple users and only one base station, the base station will suspend power to the layout entirely if it detects a short anywhere. The light bulb reduces the spike to the point where the base station's parameters can include that quick burst of power as if you had just taken a long ABBA set, each with sound, out of mute status and began to tow a long train with them. So, even if you are by yourself, and have multiple things going on on your layout, the bulb will draw power severely in the affected area, glow, give you the quick indication as to the place of the fault, and the rest of your layout, say a fast moving passenger train on a closed loop, will continue apace. No, they absolutely are not essential, and probably not very desirable in many instances. But they make my life easier, and Joe Fugate seems to like them. Crandell
richhotrain: ... Sounds like I shouldn't bother with the 1156 bulb. Given adequate feeder wires throughout the layout, my command station should shut down in the event of a short. Agree? Rich
Crandell, thanks. So noted. But, let me assure you, on my dink$1***$2layout, when two trains stop at the same time, I instantly know where the fault lies. It is at the point where the engine is lying on its side on top of the turnout where I forgot to throw the switch.
mfm37 richhotrain: Assuming that you have a good DCC system with a built in circuit breaker and no more than a 5 amp booster per power district, isn't the moral of the story that you should have adequate feeders abd properly sized feeder wires to every section of track as verified by the quarter test and forget about wiring in 1156 bulbs? Rich Rich, Your thinking is correct. But then you were told that on the NCE Yahoo group by a real live EE. Not just by us DCC users that have only experience with it and no degree. Martin Myers
richhotrain: Assuming that you have a good DCC system with a built in circuit breaker and no more than a 5 amp booster per power district, isn't the moral of the story that you should have adequate feeders abd properly sized feeder wires to every section of track as verified by the quarter test and forget about wiring in 1156 bulbs? Rich
LOL
You little devil, you have been stalking me.
DigitalGriffin richhotrain: Assuming that you have a good DCC system with a built in circuit breaker and no more than a 5 amp booster per power district, isn't the moral of the story that you should have adequate feeders abd properly sized feeder wires to every section of track as verified by the quarter test and forget about wiring in 1156 bulbs? Rich In my humble opinion there is nothing wrong with 1156 bulbs. Do I use them? No. I like tony's PSX breakers. But its a matter of personal preference. A 1156 will limit you to about 2 amps. Lets say you wire up a turnout wrong, and are shorting through the points, then the 1156 will light up. But in the mean time you are sending ~25->30Watts through the points and rail. Anything that can't handle that kind of power will melt. The thinnest point in your circuit path is what will go up first.
DG,
If I have a 5 amp system (NCE PH Pro) and adequate feeder wires throughout the layout, won't the booster trip and shut down the system before any damage can occur?
I am not challenging what you say, but what does the PSX breaker do that the booster doesn't already do?
The difference of adding additonal breakers is so that a short in one place won't shut down the whole layout. One particualr help would be if you have a helix - it could be potentially disasterous for the train to suddenly stop and start on the helix because someone elsewhere ran a turnout and the power was blippign on and off. Just adding a single breaker between the booster and the entire layout is a bit of a waste EXCEPT if you run turnouts with stationary decoders and you tape off power for those between the booster and the breaker - that way if you run a turnout and short the layout, there is still power to the stationary decoder so you can fix the problem without having to drag the loco back by hand. Usually though when installing breakers you install more than one, and gap both rails of the layout between each section.