开云体育

Resistor for block detection, best size?

Heath @ Human[c]ity Junction All Messages By This Member #4710 I have both the DR4088CS and the YaMoRC equivalent. On the DR4088CS I have added the resistors as recommended.? What is the best size resistor to use for wheelsets on N scale? ? I thought everyone used 10k ohm resistors, but a friend was using 1.5k ohm on all their cars.? I want to put 2 resistors on every cars, at opposite ends, but I want a single axle to trigger detection. But I also want to be able to have a string of 16+ cars in one zone and not trip a breaker.? What is best practice for these specific units? ? thanks -- Heath @ Human[c]ity
Iain Morrison All Messages By This Member #4711 开云体育 Heath ? For DR4088LN-CS a 10k resistor should work perfectly. ?Different systems often require different values and you cannot read across from different systems to get the value for your feedbacks. As an example a DR5088RC requires 1k5 ? Iain ? toggle quoted message Show quoted text From: [email protected] <[email protected]> On Behalf Of Human[c]ity Junction via groups.io Sent: 02 January 2025 13:35 To: [email protected] Subject: Resistor for block detection, best size? ? I have both the DR4088CS and the YaMoRC equivalent. On the DR4088CS I have added the resistors as recommended.? What is the best size resistor to use for wheelsets on N scale? ? I thought everyone used 10k ohm resistors, but a friend was using 1.5k ohm on all their cars.? I want to put 2 resistors on every cars, at opposite ends, but I want a single axle to trigger detection. But I also want to be able to have a string of 16+ cars in one zone and not trip a breaker.? What is best practice for these specific units? ? thanks -- Heath @ Human[c]ity
Dennis Cherry All Messages By This Member #4712 Seven months ago I sent an email to Karst about some testing I did on my DR5088RC unit.? Was having the problem with reliable sensor contact. ? I do use Railcom on my railroad using JMRI. ? My Railroad is N-Scale. ? Karst replied back to me and liked my novel way to fix the DR5088RC detection. ? What I did was on all the DR5088RC "J" inputs was adding a resistor shunt to the 'K' connections. ? This has stopped my senors and Railcom Reporting? from dropping out, JMRI it did not like this and would stop displaying the Railcom ID's, I would have to close and reopen JMRI. ? The chart includes using 4 each 10K resistor wheels and also tested with 3 each 10K resistors wheels to simulate having dirty wheels. ? See Attachments: ? I would recommend the 2.2K or 2.7K 1/4W resistors for N & HO. It only takes .008888 ma? per resistor. ? -- Dennis Cherry Owner/Moderator Shunt Resisitor test values.pdf Shunt Resisitor test values.pdf Shunt Resistor Setup.jpg
Iain Morrison All Messages By This Member #4713 开云体育 Dennis ? I use iTrain with DR5088RC and get solid Railcom detection without any of the shunting which you describe and I use 1k5, or 2k resistors as axle detection for wagons. I have shown a few people this method with DR5088RC and axle detection. This has worked for all of them. ? Could you do a diagram of you shunt picture as I cannot see what is being wired to where, but the boards you are using seem familiar. IIRC someone created them for the DR4088LN-CS shunts but I can’t recall the name ? ? Perhaps when I see what you have wired it may be obvious but presently I am not aware of a DR5088RC detection problem that needs solving? ? Iain ? toggle quoted message Show quoted text From: [email protected] <[email protected]> On Behalf Of Dennis Cherry via groups.io Sent: 02 January 2025 22:07 To: [email protected] Subject: Re: Resistor for block detection, best size? ? Seven months ago I sent an email to Karst about some testing I did on my DR5088RC unit.? Was having the problem with reliable sensor contact. ? I do use Railcom on my railroad using JMRI. ? My Railroad is N-Scale. ? Karst replied back to me and liked my novel way to fix the DR5088RC detection. ? What I did was on all the DR5088RC "J" inputs was adding a resistor shunt to the 'K' connections. ? This has stopped my senors and Railcom Reporting? from dropping out, JMRI it did not like this and would stop displaying the Railcom ID's, I would have to close and reopen JMRI. ? The chart includes using 4 each 10K resistor wheels and also tested with 3 each 10K resistors wheels to simulate having dirty wheels. ? See Attachments: ? I would recommend the 2.2K or 2.7K 1/4W resistors for N & HO. It only takes .008888 ma? per resistor. ? -- Dennis Cherry Owner/Moderator Attachments: Shunt Resisitor test values.pdf Shunt Resistor Setup.jpg
Dennis Cherry All Messages By This Member #4714 There are many resistor wheels available, the 10K resistor wheels are popular from different MFG.s ? In my picture of the DR5088RC the green buss bar is the "K" connections to the DR5088RC. ? You will see some 1.8K, 2.2K and 2.7K shunt resistors, all worink just fine. -- Dennis Cherry Owner/Moderator
Iain Morrison All Messages By This Member #4715 开云体育 Dennis ? Pre-made resistive wheelsets are not something I have seen in Europe, I use SMD resistors, superglue and silver conductive paint. ? You appear to be connecting to the global detector K to the buss bar, and from the DR5088RC outputs via shunt resistors to the buss bar but I cannot see where you are connecting the feedbacks for the track into, unfortunately all I can see are a jumble of read and black wires coming from somewhere and going to somewhere – hence asking for a clearer logical diagram rather than a picture. ? I also assume that when you say “Resistor Wheels 4 x 10K (2.5K)” this means four axles, each of 10k giving a resistance of 2k5 across the track? ? Iain ? toggle quoted message Show quoted text From: [email protected] <[email protected]> On Behalf Of Dennis Cherry via groups.io Sent: 02 January 2025 22:34 To: [email protected] Subject: Re: Resistor for block detection, best size? ? There are many resistor wheels available, the 10K resistor wheels are popular from different MFG.s ? In my picture of the DR5088RC the green buss bar is the "K" connections to the DR5088RC. ? You will see some 1.8K, 2.2K and 2.7K shunt resistors, all worink just fine. -- Dennis Cherry Owner/Moderator
Dennis Cherry All Messages By This Member #4716 On Thu, Jan 2, 2025 at 05:06 PM, Iain Morrison wrote: Pre-made resistive wheelsets are not something I have seen in Europe, I use SMD resistors, superglue and silver conductive paint. I do the same here, make my own resistor wheels. There are several company's that do make resistors wheels in the USA. ? You appear to be connecting to the global detector K to the buss bar, and from the DR5088RC outputs via shunt resistors to the buss bar but I cannot see where you are connecting the feedback's for the track into, unfortunately all I can see are a jumble of read and black wires coming from somewhere and going to somewhere – hence asking for a clearer logical diagram rather than a picture. I did not show all the wiring because that does not change on wiring the DR5088RC, just adding the resistors is all I am doing. ? I also assume that when you say “Resistor Wheels 4 x 10K (2.5K)” this means four axles, each of 10k giving a resistance of 2k5 across the track? Yes ? -- Dennis Cherry Owner/Moderator
[email protected] All Messages By This Member #4811 I use iTrain with DR5088RC but don't have axle detection for wagons.? I can understand how resistors would work for current detection, I don't understand how they work with Railcom as resistors are passive devices and Railcom requires a locomotive/wagon DCC address to work. Can someone please clarify for me.
Iain Morrison All Messages By This Member #4812 The resistor axles have no impact upon Railcom and simply provide occupancy for the wagon. FYI Railcom has nothing to do with occupancy, it is simply reporting the details from the decoder. The actual occupation comes from the current draw by the locomotive (or wagon). Many Thanks Iain Morrison toggle quoted message Show quoted text On Thu, 20 Mar 2025 at 12:17, alanmayfield via <alanmayfield=[email protected]> wrote: I use iTrain with DR5088RC but don't have axle detection for wagons.? I can understand how resistors would work for current detection, I don't understand how they work with Railcom as resistors are passive devices and Railcom requires a locomotive/wagon DCC address to work. Can someone please clarify for me.
[email protected] All Messages By This Member #4813 Thanks for that Iain.? Would you add the resistors to wagons when using iTrain as the length of the loco/wagon combination is calculated by iTrain?
Iain Morrison All Messages By This Member #4814 Whist iTrain can calculate the train length placing resisting axles at the back of trains lets iTrain see the back of the train - especially useful for reversing or if you lose part of the train because it will keep the block(s) occupied until you ‘find’ the back of the train again. Many Thanks Iain Morrison toggle quoted message Show quoted text On Thu, 20 Mar 2025 at 13:11, alanmayfield via <alanmayfield=[email protected]> wrote: Thanks for that Iain.? Would you add the resistors to wagons when using iTrain as the length of the loco/wagon combination is calculated by iTrain?
Chadbag All Messages By This Member #4826 开云体育 On Mar 20, 2025, at 06:19, Iain Morrison via groups.io <w.iain.morrison@...> wrote: FYI Railcom has nothing to do with occupancy, it is simply reporting the details from the decoder. The actual occupation comes from the current draw by the locomotive (or wagon). So let me ask a dumb question, as I’ve only set up sample blocks with DR5088RC and have seen the RC ids show up in my blocks but don’t actually detect any current. The question: Why do I care about he occupancy current? ?If the RC id is showing its obviously in the block. ?It won’t show an id for the block if it’s not in the block. ?I get the technical difference, but functionally, it is detecting occupancy. ?Because, as I said, the existence of the id shows its occupying the block. My question is one of understanding as my current “layout” is a simple oval to test my software as I get set back up in our new home over time and start a bigger and more complicated test layout and then a “real layout” to keep me going until I die :) Thanks Chad
Iain Morrison All Messages By This Member #4827 开云体育 You will see that the block detection (i.e. when current is drawn) appears slightly before the Railcom ID is displayed. This is because it is faster being almost the instant a loco enter the block. The Railcom ID is then obtained from the loco and sent via Loconet to the command station. It is a sequential process and will always be sequential. ? The current is drawn by the decoder, even if the loco is stationary, and without a decoder you cannot get a Railcom ID. ? Iain Morrison ? ? toggle quoted message Show quoted text From: [email protected] <[email protected]> On Behalf Of Chadbag via groups.io Sent: 25 March 2025 03:49 To: [email protected] Subject: Re: Resistor for block detection, best size? ? ? On Mar 20, 2025, at 06:19, Iain Morrison via groups.io <w.iain.morrison@...> wrote: ? FYI Railcom has nothing to do with occupancy, it is simply reporting the details from the decoder. The actual occupation comes from the current draw by the locomotive (or wagon). ? ? So let me ask a dumb question, as I’ve only set up sample blocks with DR5088RC and have seen the RC ids show up in my blocks but don’t actually detect any current. ? ? The question: Why do I care about he occupancy current? ?If the RC id is showing its obviously in the block. ?It won’t show an id for the block if it’s not in the block. ?I get the technical difference, but functionally, it is detecting occupancy. ?Because, as I said, the existence of the id shows its occupying the block. ? My question is one of understanding as my current “layout” is a simple oval to test my software as I get set back up in our new home over time and start a bigger and more complicated test layout and then a “real layout” to keep me going until I die :) ? Thanks Chad ?

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