RMweb Gold Vistisen Posted September 11, 2021 RMweb Gold Share Posted September 11, 2021 Hi I need some advice about how to power DccConcepts accessory modules. I have a layout where I have two buses running via four pin XLR connectors between each baseboard, one for track power and one for accessory power. I have a NCE power cab and a Cobalt ALPHA control panel that are connected to a 5 amp Cobalt Alpha box with DCD-PWR power supply. This in turn is connected to the two buses via a Dcc Specialties Psx1, so that the control bus is on its own section. I have 11 Dcc Cobalt alpha point motors, + 5 Cobalt SS controllers connected to about 14 SS pointmotors (some are crossovers running two points off a single output) I also have two SX-8 solenoid units controlling 16 peco points in my storage yard. My problem is that even with no trains on the track, on switching on the power, the current draw is too much for the 5Amp power supply to cope with, and it goes into overload. Do you have any suggestions as to how I can solve this problem? Should all these units be connected in serial or parallel? At the moment the SS accessory modules that are under the same baseboard are daisychained via the terminals provided for doing this on each unit, so they are grouped as three on one board, and two on another. The two SX-8 units are also daisy chained together. I have considered mounting on/off switches to each daisy chain group so that I can minimize the power surges on starting. But is there a more intelligent way of doing things? I can’t be the only person who has run into this problem. Link to post Share on other sites More sharing options...
Pandora Posted September 11, 2021 Share Posted September 11, 2021 (edited) I do not have a tried and tested solution, but would a Thermistor (Thermal Resistor) in the main feed solve the problem? A thermistor has a high resistance of ohms when cold, but the resistance in ohms reduces as the thermistor warms up, the high resistance would limit the current rush on powering up, but permit higher current when all is in a powered up steady state Link to Thermistors on Ebay: https://www.ebay.co.uk/itm/363386160003?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D20201210111314%26meid%3Db03dfc6c72784dc6aa36b348522b3bf5%26pid%3D101195%26rk%3D1%26rkt%3D12%26sd%3D384150273979%26itm%3D363386160003%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DSimplAMLv9PairwiseWithPLXWeb%26brand%3Duxcell&_trksid=p2047675.c101195.m1851&amdata=cksum%3A363386160003b03dfc6c72784dc6aa36b348522b3bf5|enc%3AAQAGAAACAGixbIMb6Uc9OL9QLIzBizK9Ax8aAhUJ7jlYTCNsvj38BYEAPvaMMrTdoGKD5ALin%2FsbWq6CgkRJJmpzG3GH7CdXFsHSOxC2pRAP8V1lPfh4FaojDyL%2BbIohuvLphiINyftiAvlZ5Xbm83rzcNvRWUYsph3rJrtaP4aO3qXTgMI8LhaxBRND8quGsHH5IbzKyTrpNQT%2BoMOI1vRVtk02roibuMAicfG59eT5XKgNtG5PWz7ahXMf%2BorIoWP959cMj6VIfMBDREfC2uFATzf0krmTkZ6OJ5kHjhprWDWaKchfaLJhL396ONe8dp2%2Fv%2FNGY6q93OCoW98E%2FfLKtNuH5OJUq1BEcNtZ41nM7U4bHt46gSbAR6D8IbWE9jWC8S6hpNQ%2FosjnX5hQlXRfdiqRDbsze3q5Wpym7sIrqPFePwMspwChefdVAepaRUyBroPe%2Fen9r7A%2BHPIyKYfo2DptQfLsC2wvHMhd2tfECNMIcGgyCiODiKq4ZrMzc4AjXx1GHG%2B1Xjgvbp7CWelTAQavjvsNZwYPyOEIeE%2FjRG8vocxsODRm%2FrciSJ2S92z5ayc4O41L2nXqf0LJqzzD440qXqF6vMf2l5BxnhGdvzCJRbaYGsYus1TL%2BYIUEiwzkA9R6kA%2FUZn404y%2B%2FdG7vmXCtVbrOjnp%2Bk0yk6Q7zhwPaSc9|ampid%3APL_CLK|clp%3A2047675&epid=2232393134 Edited September 11, 2021 by Pandora 1 Link to post Share on other sites More sharing options...
WIMorrison Posted September 11, 2021 Share Posted September 11, 2021 I suggest it is your SX-8 that are causing the problem, and you could either try as above (one of the feed to each device) or simply a switch in the line and switch them on individually to stop the multiple CDUs causing the excess draw. 1 1 Link to post Share on other sites More sharing options...
Stephen Freeman Posted September 11, 2021 Share Posted September 11, 2021 I think the problem of too many accessory decoders trying to start all at once is a well known problem. I can only offer a suggestion based on the use of PanelPro and Computer. In effect what was needed was a start of day routine. I think it is now included as an option (it was about 18 years ago that I had to write the macro). Basically all the motors needed to be reset on startup but a short time delay is necessary to ensure enough power was available to each decoder output . So a macro was needed. to ensure that each decoder wasn't trying to power all it's outputs at the same time. More important with the use of PanelPro so that the actual positions tied up with what was on screen. Of course if the decoders were able to report back their position it wouldn't have been needed so much from that point of view . How you might implement it on a DCC Concepts system is not known to me. 1 Link to post Share on other sites More sharing options...
SamThomas Posted September 13, 2021 Share Posted September 13, 2021 If you have to resort to manual switching you could try wiring a car headlamp bulb/lamp/globe in series with the PSU output - wire a switch to "short out" the bulb & see if that does the trick. Link to post Share on other sites More sharing options...
Andymsa Posted September 13, 2021 Share Posted September 13, 2021 Tam valley did a device that solved the inrush current issue by having a device that introduced a soft start. I’m not sure if still available. Link to post Share on other sites More sharing options...
Crosland Posted September 13, 2021 Share Posted September 13, 2021 9 hours ago, Andymsa said: Tam valley did a device that solved the inrush current issue by having a device that introduced a soft start. I’m not sure if still available. They have reduced their range as the owner is retiring to concentrate on his layout, due to being diagnosed with cancer. There's a note on the website. Link to post Share on other sites More sharing options...
Andymsa Posted September 13, 2021 Share Posted September 13, 2021 16 minutes ago, Crosland said: They have reduced their range as the owner is retiring to concentrate on his layout, due to being diagnosed with cancer. There's a note on the website. yes I saw that earlier very sad, but there could be old stock out there still. Link to post Share on other sites More sharing options...
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