Post by: TwinStar on January 03, 2019, 07:06:23 PM
Each track will be gapped and isolated. Each track needs two switches, one on each side of the module, and I would like for the switches (I don't really care about style) to be illuminated on when the track is live. Some of the lights in my house work with a similar setup so I know the concept is doable but I just don't know how to do it.
Any input on wiring or hardware would be much appreciated.
Post by: G8B4Life on January 03, 2019, 09:03:03 PM
I don't think having the switches themselves light up is doable for most switches, you'd need a switch with separate light inputs (most just light up from the power they are switching) in which case you'd simply extend the bridge/LED (only one shown, you'd want one for each side of the module) to the switch instead of the fascia.
The bridge rectifier is of course required for when DCC is powering the tracks.
While this way is simple all that wiring might be tedious. I wonder of Alan could come up with a simple but way cool push on/push off system that works from both sides of the module?
- Tim
Post by: Alan on January 03, 2019, 10:17:24 PM
If in a similar situation you require many switch locations then it would make more sense to control a track power relay with a flip flop circuit such as this one found on Bill Bouden's site http://www.bowdenshobbycircuits.info/page9.htm#4013.gif (http://www.bowdenshobbycircuits.info/page9.htm#4013.gif). With this circuit controlling the relay you could use as many momentary push buttons as you wish all connected with a single small gauge wire pair. The schematic makes it look far more complicated than it really is. All parts are super common dirt cheap components and could easily be made on a little 2" x 2" breadboard for $5 or so.
Post by: TwinStar on January 07, 2019, 10:30:12 PM
Thank you both. I'm undecided where I want my kill switches. The Union Station tracks approach 20' and I'm trying to decide if I want kill switches located in the center of each side of if I want kill switches on each end of each side (4 then in this case).
Alan, is that schematic something that I'd have to build?
Post by: Alan on January 09, 2019, 07:52:24 PM
Post by: TwinStar on January 13, 2019, 12:23:33 PM
https://www.ebay.com/itm/DC12V-Switch-Control-Relay-Bistable-Trigger-action-Circuit-Module/262613032443?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D20131003132420%26meid%3Df5d9faaa1128461eaddf756a697af117%26pid%3D100005%26rk%3D1%26rkt%3D5%26sd%3D132703163629%26itm%3D262613032443&_trksid=p2047675.c100005.m1851 (https://www.ebay.com/itm/DC12V-Switch-Control-Relay-Bistable-Trigger-action-Circuit-Module/262613032443?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D20131003132420%26meid%3Df5d9faaa1128461eaddf756a697af117%26pid%3D100005%26rk%3D1%26rkt%3D5%26sd%3D132703163629%26itm%3D262613032443&_trksid=p2047675.c100005.m1851)
Is this the entirety of what I need save for wire and switches? I'd assume a 12V+/- input for power, multiple wire pairs from each switch, and then a singe or dual in/out for one or both track feeders?
Post by: Alan on January 13, 2019, 12:34:35 PM
Is this the entirety of what I need save for wire and switches? I'd assume a 12V+/- input for power, multiple wire pairs from each switch, and then a singe or dual in/out for one or both track feeders?
Yep. You have it all correct. China just made life real easy for you.
Post by: TwinStar on January 13, 2019, 02:17:05 PM
Is this the entirety of what I need save for wire and switches? I'd assume a 12V+/- input for power, multiple wire pairs from each switch, and then a singe or dual in/out for one or both track feeders?
Yep. You have it all correct. China just made life real easy for you.
Awesome. Now more stupid questions if I may.
Will these open/close the circuit on both rails or just one?
I assume I need momentary style switches? SPST?
I also assume an LED wired in parallel with the track circuit would indicate track status?
Thanks so much.
Post by: Alan on January 13, 2019, 02:36:06 PM
Yes, momentary contact switches. SPST
Yes, LED wired in parallel with track. Don't forget the current limiting resistor. If the track will ever see DCC power then you should also wire a regular diode in series with the LED to prevent damaging the LED when the DCC power is on the negative pulses. A regular diode will add an additional 0.7V drop so remember to include in your limiting resistor calculation.
Post by: TwinStar on January 13, 2019, 04:24:07 PM
The relay supplied on the board is SPDT so it will switch on/off only one rail. You would need a DPST or DPDT relay to switch both rails. Why do you need to switch both rails? An open circuit is an open circuit regardless of how many opens there are in it.
Yes, momentary contact switches. SPST
Yes, LED wired in parallel with track. Don't forget the current limiting resistor. If the track will ever see DCC power then you should also wire a regular diode in series with the LED to prevent damaging the LED when the DCC power is on the negative pulses. A regular diode will add an additional 0.7V drop so remember to include in your limiting resistor calculation.
Alan, I was planning on only opening one rail to cut power but I thought someone had posted a need to open both. Thanks for affirming my original plan.
I'll get on Digikey and find some cool ones.
It will see both DCC and DC. I'm sure I'll be back confirming my resistor calculation!
Thanks again, I really appreciate the info.
Post by: TwinStar on January 13, 2019, 06:22:04 PM
Something like this?
SPST-NO circuit with an OFF-MOM function?
https://www.digikey.com/product-detail/en/e-switch/RP3502ABLK/EG1900-ND/280446
Post by: Alan on January 13, 2019, 06:58:29 PM
Post by: TwinStar on January 13, 2019, 07:30:36 PM
Yep
Awesome, thanks!
Post by: Alan on January 13, 2019, 09:04:45 PM
- Connect the track to the NC side of the relay. That way you don't lose the track if something goes wrong with the China circuit / power supply / wiring / switches.
- Connect your LED/resistors at the China circuit board terminals to make the rest of the under-module wiring connection free.
- You could wire green LEDs to the track side (NC) of the relay and red LEDs to the NO side. That way you have red OFF and green ON indicators.
Post by: TwinStar on January 14, 2019, 10:53:39 AM
Had a few thoughts...
- Connect the track to the NC side of the relay. That way you don't lose the track if something goes wrong with the China circuit / power supply / wiring / switches.
- Connect your LED/resistors at the China circuit board terminals to make the rest of the under-module wiring connection free.
- You could wire green LEDs to the track side (NC) of the relay and red LEDs to the NO side. That way you have red OFF and green ON indicators.
Alan:
1. That's a good idea. I ordered a spare too in case of a failure at a setup.
2. I don't think I follow
3. That's a really good idea.
Post by: Alan on January 14, 2019, 11:42:40 AM
Post by: TwinStar on April 01, 2019, 03:16:38 PM
Rather than having connections for the resistors and diodes along the wiring under the module, cut the leads of the resistor and diode really short, solder together and to wire, cover with heat shrink, and finally use the remaining short lead to insert into the circuit board connector. Not only will it make it a neat installation it will also be easier to troubleshoot if there is a problem. All your discrete components and connections will be right at the circuit board.
Thanks Alan, that make sense.
Post by: TwinStar on April 01, 2019, 03:21:48 PM
12+ self explanatory
GND self explanatory
Trigger Switch: all four of the momentary switches to this. I think it was mentioned to use RJ12 flat type wire.
NC: this is the OUT to the rail that I want switched.
EMPTY: Do not use
COM: this is the IN to the rail that I want switched.
NO: Is this used with the track status LED's?
Post by: Alan on April 01, 2019, 03:38:57 PM
The track status LED on the NO connection will light when the track is un-powered (switched off). The track status LED on the NC connection will light when the track is powered (switched on). Alternately, you could simply hook the NC LED directly to the switched track to eliminate wire(s) from the wiring run.
Since the LEDs are powered by DCC track voltage (which is AC power) it would be prudent to add a diode in series with each LED to prevent reverse voltage (negative DCC cycle) from possibly damaging the LED. LEDs are reasonably tolerate of reverse voltage but why take the chance. Any common diode will work.
Don't forget to use the proper dropping resistor with each LED.
Post by: TwinStar on April 01, 2019, 08:51:58 PM
Thanks for the confirmation. This module will be DC powered at home and DCC at Free-mo setups. I assume the diodes will work with both?
Post by: Alan on April 02, 2019, 05:52:11 AM
Post by: TwinStar on April 02, 2019, 08:51:06 AM
Post by: TwinStar on April 09, 2019, 03:16:59 PM
Post by: Alan on April 09, 2019, 03:18:38 PM
Post by: TwinStar on April 09, 2019, 03:18:46 PM
Post by: TwinStar on April 09, 2019, 03:19:11 PM
yes
Thanks!