I've got 12 Tomar Dwarf Signals on their way. I noticed on Tomar's site that they sell packets of resistors for the LEDs/signals. Does anyone here know if the signals come with the required resistors? If not, which value (is that the correct term?) is required? I'm using two light (red/green) Dwarfs, not the searchlight/shade style if that matters. They will be used as turnout thrown indicators. I can always contact Tomar of course, but not 'til Monday.
Thanks.
Jim
Raised on the Erie Lackawanna Mainline- Supt. of the Black River Transfer & Terminal R.R.
If the signals have LED lights, they are quite forgiving, just so long as you use a resistor. I have used 1KΩ resistors for years. More recently I have moved to 510Ω resistors without any difficulty. I buy my resistors by the thousand, much cheaper that way.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Jim,
While Tomar Industries provides resistors with some of their products like crossing signals, they do not provide resistors for dwarf signals.
The instruction sheet that comes with the dwarf signal suggests a 1500 ohms, 1/2 watt, resistor for the red LED and a 390 ohms, 1/2 watt, resistor for the green LED.
I have a bunch of the Tomar dwarf signals on my layout. The key is to balance the color of the red LED to the color of the green LED.
Since the red LED appears so much brighter, you need higher resistance. I follow Tomar's advice and use a 1.5K ohms, 1/2 watt, resistor.
For the green LED, I use a 470 ohms, 1/2 watt, resistor. Tomar's suggested 390 ohms, 1/2 watt resistor works just fine, but it makes the green LED just a bit too bright for my liking.
Rich
Alton Junction
thank you Lion and Rich. I had no idea that the different color LEDs had different brightnesses and requirements. Hopefully my dwarfs will show up tomorrow or Tues. My buddy who helped me today with a 7 hr. tortoise install(s) said he had a huge selection for me to take my pick from.
Any other tips for installation? Just drill some holes and drop the wires through the bench top to the Tortoii I'd think...
Getting an electrical education little by little now that the layout is far enough along to finally enter that zone and spend AT least some time with DCC programming, etc.
Capt. Grimek Any other tips for installation? Just drill some holes and drop the wires through the bench top to the Tortoii I'd think...
The wires on the dwarf signal are extremely thin and fragile.
What I do is to gently strip about 1/4 inch of insulation off of each wire (red, green and white) with an Exacto Knife blade. With the red and green wires, I twist the exposed wire around one leg of the resistor and then solder the wire to the resistor. Then, I twist a matching colored 22 gauge wire to the other leg of the resistor and solder the wire to the resistor. As for the white wire, I gently twist the wire from the dwarf signal to a piece of 22 gauge white wire and solder the connection - - no resistor required on the white wire.
After the three wires are soldered, I use heat shrink tubing on each of the three wires, completely covering the resistor on the red and green wires. The heat shrink tubing protects the wires from touching one another. If the bare wires were to touch each other above the resistor, the LED would immediately burn out. The heat shrink tubing also provides an added degree of sturdiness to the wire connections. The thin dwarf signal wires can easily break if pulled too hard, and I have completely severed the wire from the signal on more than one occasion. So, be careful and protect the wire connections with heat shrink tubing.
Once you have soldered the wires and covered the connections with heat shrink tubing, you are ready to "drill some holes and drop the wires through the bench top to the Tortoii". The 22 gauge wires that will be connected to the Tortoise are much stronger than the thinner dwarf signal wires.
Capt. Grimek thank you Lion and Rich. I had no idea that the different color LEDs had different brightnesses and requirements. Hopefully my dwarfs will show up tomorrow or Tues. My buddy who helped me today with a 7 hr. tortoise install(s) said he had a huge selection for me to take my pick from. Any other tips for installation? Just drill some holes and drop the wires through the bench top to the Tortoii I'd think... Getting an electrical education little by little now that the layout is far enough along to finally enter that zone and spend AT least some time with DCC programming, etc. Jim
LIONS cannot afford to buy signals, yet a subway layout needs them by the 100s to look like a subway layout. I built them from 1/4" x 1/4" dimensional wood, drilled holes and set LEDs in place. The (-) side of the LEDs are all soldered together to a single 1KΩ resistor and the (+) sides go to what ever device I am using to switch the signals.
I drill a 1/4" hole into the table top, and force fit the signal, wires and all into it. It makes a very stable installation, I add some modeling clay and some paint to the back of the signal to prevent back-lighting and to give it a more finished look.
By the way, what are you hooking the signals up to?
The supply voltage will determine the size resistor you use. If you use a driver board such as the Digitrax SE8C, you don't use a resistor. If you are using 12volt, you would use a 1k resistor.
Springfield PA
Hamltnblue By the way, what are you hooking the signals up to? The supply voltage will determine the size resistor you use. If you use a driver board such as the Digitrax SE8C, you don't use a resistor. If you are using 12volt, you would use a 1k resistor.
The OP says that he is connecting the dwarf signals to Tortoises as I do, but he doesn't indicate the source of the power supply. I use an MRC Railpower 1370, an 18 volt DC power supply.
Hi, Thanks Rich for the wiring specifics. I was just about to ask! I'm using the Tortoises' 12 volt wall wart which is reputed to power up to 30 turnouts. Is this fine? Will 12 signals rob enough juice to make any difference?
My friend who is willing to give me some resistors from is stash has:
1500 ohm 1/2 watt
470 ohm 1/4 watt and
750 ohm 1/2 watt resistors
Any issues using any of these? If so, I can certainly afford a few resistors as indicated by Tomar's sheet which arrived this a.m.
I'd like them to be pretty bright for when all of the track lighting is on which would be 99% of the time.
Thank you
Capt. Grimek Hi, Thanks Rich for the wiring specifics. I was just about to ask! I'm using the Tortoises' 12 volt wall wart which is reputed to power up to 30 turnouts. Is this fine? Will 12 signals rob enough juice to make any difference? My friend who is willing to give me some resistors from is stash has: 1500 ohm 1/2 watt 470 ohm 1/4 watt and 750 ohm 1/2 watt resistors Any issues using any of these? If so, I can certainly afford a few resistors as indicated by Tomar's sheet which arrived this a.m. I'd like them to be pretty bright for when all of the track lighting is on which would be 99% of the time. Thank you Jim
The Tortoise 12 volt wall wart will work just fine, and it will easily handle 12 Tortoises with the dwarfs wired in.
The 1500 ohms 1/2 watt resistor should be used on the red LED.
The 750 ohms 12 watt resistor will probably dim the green LED too much for your liking.
I cannot say for sure, but the 470 ohms is perfect for the green LED although I am not certain about the 1/4 watt. My guess is that it is OK for this purpose, but I would recommend the 1/2 watt.
Can anyone help here? Is the 1/4 watt OK for this purpose?
IF you are connecting the LED in series with the tortoise, you probably do not need a resistor as the tortoise will do this for you. LION hooks his up between the tortoise control and ground, and thus does need a resistor.LION uses a 1KΩ resistor and notices no problems with how bright the LEDs are.
LION uses 1/4 watt resistors with no problem.