Function-only decoder for lighting a structure

[tstage]

I'm playing around with the idea of using a function-only decoder to independently control exterior and interior lights of a company house on my layout.  TCS makes a 4-function one (FL4) that costs ~$17.

What I'd like to do is to hook up two (2) exterior lights for the front and back porch and two (2) interior lights for the front room and a upstairs.  (See pic below)  I could then turn on or off individual lights via the decoder.  Here's a transparent diagram of what I have envisioned:

The decoder will be attached to the back wall with double-stick foam tape and the red and black wires will connect it to the track bus (as per the diagram on pg. 1 of the TCS FL4 manual) via the wire conduit so that I can communicate with/program the decoder.  A wire for each of the four (4) incandescent bulbs would be soldered to its own function pad on the decoder and the other wire would be soldered to the common (+) wire:

Each function is rated at 200mA, which is way more than enough to handle a 30mA incandescent bulb.

What I will need to determine is whether or not the function-only decoder has built-in resistors...or if I need to add them for the 1.7mm - 1.5V incandescents I plan on using.  If I do have to add them (and I'm guessing that I probably will) then I'd like to use SMD resistors to keep things "small".

My questions:

1. Does this idea seem feasible?
2. Are there any shortcomings that you perceive (or that I've overlooked) in trying something like this?
3. If I do need resistors, I would add them to each of the green, violet, brown, and pink pads?
4. Would the number of resistors (4) be a concern in regards to heat dissipation?

Up until now I've avoided using track power for lighting any of my structures.  However, as mentioned, this gives me a unique opportunity to individually control four separate light fixtures in my company house on the fly via my NCE throttle, with only a 120mA reduction in track power.  This also minimizes the amount of wires coming up through the wire conduit, were I to try this "conventionally".

Anyhow, thanks for your help in advance. 

Tom

[richg1998]

If the decoder does not specify resistors on board, you need to add resistors. All the decoders I have installed, indicated needing resistors if the decoder did not com with them. A couple for diesels did have connections for 1.5 volt bulbs and did not need resistors but this is not what you hve.

TCS also sells the 1.5 volt regulator.

Below is a good link. Scroll down near the bottom of the page. Store the link in Favorites.

http://www.members.optusnet.com.au/nswmn1/Lights_in_DCC.htm

Rich

[rrinker]

 The FL's need resistors. You should be OK on current. The voltage regulator is a better option than resistors, you won;t be using SMD resistors to drop voltage for 30ma 1.5V bulbs - you need near 1 watt resistors for that.

 It's an interesting idea, maybe even worth the DCC cost of an extra booster to run a bunch of houses, if you want to have progressive lighting such as having the porch light and downstairs light come on in the early evening, then an upstairs light later at night - all could be controlled with scripts timed to the fast clock in JMRI (which via Insteaon lighting control can dimt he room lights too, for the full day/night cycle.

 Alternative is a control device like the Aux-Box which gets commands via the DCC bus, drawing very little power, and switches relays so the lights can be powered by some other power source. For my purposes I'd consider a LocoIO board with relays, since I use Digitrax. Those get the commands from loconet but are remotely powered, and for 16 lines of I/O are relatively cheap. Another thought - both those devices use accessory addresses NOT loco address like the FL4 will, so no taking away or overlapping loco address numbers.

 Gonna put a mailbox out at the street with the house address on it so you know what address to dial up?

                --Randy

 

[locoi1sa]

Tom.

 Did my sand and gravel plant with an FL4. Red LEDs for the loading tracks and outside lighting on the walkways and stairs. I use a short address of 1 and can turn on and off the LEDs and lights from my throttle. I wired resistors to the LEDs and the bulbs in the lamps.

http://s1081.beta.photobucket.com/user/locoi1sa/media/SAM_0111.jpg.html?sort=3&o=8

http://s1081.beta.photobucket.com/user/locoi1sa/media/SAM_0110.jpg.html?sort=3&o=9

The lights next to my scale house are bulbs and wired through a toggle switch and resistor to the track buss. They are not on in this photo.

http://s1081.beta.photobucket.com/user/locoi1sa/media/SAM_0116.jpg.html?sort=3&o=4

  My modules are now retired and going into a permanent home layout. The shows were fun for awhile but got expensive and time consuming.

      Pete