Can anyone point me to a SPECIFIC device, preferably a part number, that I might find at a local electronics store, for reducing the voltage on a power supply from an apparent 16.1 volts per a Tony's Trains DCC meter to a safer 9 volt to 11 volts. If 11 is to high, what is this most satisfactory that will run DCC properly? I think I can reduce the voltage to about 11 volts on a Lenz system via Decoder-Pro software instruction, but have not yet tried it. I searched the forum and didn't come up with anything which means I am using the wrong words. Thanks.
On page 3 of this thread there is a diagram of what I think you refering to. http://www.trainboard.com/grapevine/showthread.php?t=82441&highlight=voltage
MRC used to sell the diode bank voltage reducer, but for some reason discontinued them. Michael Hilliard said he was making them for sale today in chat.
Many thanks. I was in chat for just a bit when Ellen was having Internet troubles, and Michael was in/out several times. I'll contact him.
Don, if your using a Lenz LZV100 Command Station you need 14-16 Volts to operate the Station, Page 18, Section 7.1.1 of the manual. Voltage not to exceed 18 volts. You can set the Track Voltage down to 11 Volts using Ops Mode Programming per the Table on Page 16 of the manual using CV7. Hope this helps you. Bob
AS I understand the manual I dial in "engine 00" and set CV7 to 50 and the within 15 seconds set CV7 a second time to 22. This gets me 11 volts at track level. In lots of reading many IMPLY that 11 volts is too high, and it should be down around 9 for DCC in Z. Any comments. BTW if you are running JMRI Decoder pro you can make the voltage setting as a software change on the fly - which I guess is the same as calling up "engine 00", now that I think about it. Old man here and late Sunday night. ...don
Hi Don, Another old man here too and this DCC sure gets deep sometimes. I don't think 11 volts is too high. The voltage is only going into the decoder and nowhere else. The motor will only see a small portion of that as you never run the loco at full throttle. I'm not sure about lighting but the decoder controls that too in most cases and you only have to use a resister to reduce the voltage there if neccesary. I don't know if the small LED's are voltage specific or not but I'm sure pray59 would know, hes always working with these DCC installs. I know alot of guys in N scale that leave the track voltage at 15 or 16 volts, depending on how many locos they want to run at the same time and all the motors in the N Scale locos are 12 volts and it doesn't hurt them at all. Bob
This is Atlas' method for reducing voltage to the track. Not as easy as a simple programing change but it works. http://www.atlasrr.com/voltage.htm Eric
you are entitled to your own opinion, but this is simply mis-information based on the lack of basic knowledge about how DCC works:thumbs_down: the motor will always "see" full voltage, regardless whether you run half or full throttle, the only thing that will change is the pulse width. Chris
O.K., Therein lies the rub and that is really my basic question. What is a safe voltage that the supply can put out, that the engine sees? If I hold my finger in the candle flame it hurts. If I zip my finger through the flame I feel nothing. If a DCC motor never sees more than a voltage - whatever it is - more than say 60% of the time [i.e.the pulse width], what voltage is safe?? If Robert tunes in here again, could you post a couple of your sheets showing all your CV settings say from a DZ123 decoder?
there is another Don A, asking the same question on Z_Scale_DCC Yahoo Group, with excellent answers and explanations being given by Robert Allbritton and Glen Chenier ... (is this you? or do we have multitude of Don A's ? :zip see: DCC track voltage for Z motors the consensus seem to be 10Vmax (I personally run on 9.8V) Chris ps you finger through the flame analogy misses one point - you don't zip your finger through the flame once. You do it repeatedly without being able to cool your finger adequately (less cooling at lower revs), so the effect of "zipping" your finger through the candle is the same as holding it there all the time (particularly for coreless motors)
Probably same "Don A", but I still have not seen an answer as to what is a truly safe maximum voltage. There seem to be a lot of exceptions and possibilities and theories, but so far I have not seen anything that seems to be agreed upon by some electrical engineers. Just the simple thing of constant voltage vs percent of time the engine actually sees the voltage seems to just starting to being understood by the majority of us, since decoder documentation itself is poorly written when it describes "starting voltage" or "maximum voltage" where in reality they are the same. I was looking for a a gizmo and it's part number available that I can vary the voltage downward from the power supply however I am well aware this may not be the item I really need. I just do not want to burn out motors. Robert suggested I contact Michael which I've done, but he hasn't had a chance to answer yet.
bit shy, aren't we :angel: repeatedly stated, as at or slightly below 10V (of course dependant on the motor used) internet is full of both, useless BS and most useful info. If you are not in a position to discern the difference between the two, than you are in a vulnerable position... it is a technical hobby and it assumes ability to learn :thumbs_up: you are indeed right, these are very poor explanations, which refer to "average" /"equivalent" voltage , so 12 V switched on 50% and off 50% time is referred to as 6V :angry: the only available "gizmos" do not allow you to vary the voltage, they only drop it to a fixed point (dependant on the number of diodes used) Michael Hilliard is apparently making one, but otherwise it is down to you making one - not that difficult and plenty of instructions available (see elsewhere on the Trainboard) Chris
I don't know what the safe limits are for sure, but I have not ruined a motor with the DCC booster output set to 10 Volts RMS AC as measured with a Fluke 77 true RMS meter. Yet.
Giday! It's a very nice forum you have here folks.Been reading it for a few weeks and thought I'd say giday.Just bought Märklin 81562 and just so happy with it.[starter set with a BR 74] Most impressed with your Z digatal threads as that's the path I want to follow. Back in 1989/1990 Märklin was offering Digital Z . Does any one know what there answer was in delivering a safe voltage to the track and lok.
Hi Rowan, Welcome to Trainboard! I have only been in Z Scale for almost 4 years, and have never heard of the Marklin Digital in Z Scale, so I don't know if it is still around. I think the DCC standard is growing faster than the other formats though, because many of the Selectrix and Motorola format decoder makers are now offering DCC format too now. Actually, DCC format is a European standard, invented by Lenz, and they gave away their protocol standards to the NMRA and all the other manufacturers, which is why it became popular I think.
:no: Well this is NOT (all) true. The 50% is :wink3ed: No voltage changes, there still is the 12V, it's just that it is either there (on) or not (off) 50% of the time. The decoder manuals call it "voltage" but it is really the equivalent voltage, as if you put a DC voltmeter on it. Because the motor and meter are very slow reacting, a meter would effectively see half the voltage. For Min Volts, it is On for the smallest amount of time but still to the full 12V then off for a long period, then back on again for a very small amount. Identical to the old school DC power packs with Pulse Power. Effectively the loco "sees" a very low effective voltage as it is not there very long. At Max volts, it is on "all" the time at the 12 v. At Mid Volts, it is 50% on at 12V, then off for 50% so the motor see the equivelant of 6v (if you put a DC meter on the motor). Now, this pulsing is very fast, in the KHz range so the motor should crawl really nice with even the lowest "voltage" The 12V in the above example is not on everyone's DCC, it is what's left over from the original track rectification and motor driver loss. ~9V for us that run 10V DCC, more like 12-15V for those whom have not either turned down the volts or dropped it with the diode strings.
OK, now lets really confuse the issue. Does it make any difference to the motor whether it sees 50% on and 50% off as opposed to 25% on - 25% off - 25% on - 25% off. If someone can answer who KNOWS that would be great, as some of the "help" here has been a little self assuming. I'd like to know if the motor will run better/cooler or whatever under one of the above two situations. If there is no difference then we may be worrying about nothing as long as you are not running at sub-orbital speed all day long. In other forums where folks have contacted Digitrax, the factory has ducked the answer. I've asked the USA Lenz representative Debbie Ames and received a pretty cloudy answer. I asked Mr Lenz in Cincinnati at the NTS in 2005. He did give me an answer, but I don't speak German and a LOT went over my head. Can someone tell us how DCC really operates? Yes DCC time slices, but what does the wave REALLY look like as you move up/down the speed curve?
