I know little about electronics, and you guys could probably do this in your sleep, so I ask here. Most of you are familiar with the Tomar Drumhead, it includes a ballast light so the drum doesn't fry.
The Spectrum observations are already lighted, and pull power from the rail, to a contact plate on the floor of the car. Then a spring on wire runs it up the window plastic to the lights in the roof. It's a great design for making the roof removeable.
My question, can I wire the Tomar into that lighting gig? The interior doesn't give room for the ballasting light.
-Morgan
I'm sort of familiar with the Tomar drumhead lights, but I don't remember what voltage they require. That would be important. Let us know.
Hmm. The drumhead light is a 1.5volt bulb, I don't see a rating on the "ballast light" but it's a big sucker.
The ballast light that came with my drumhead was an auto marker light. A 194LL. I haven't finished installing it yet in an IHC tail car (no other lighting), but I agree, it's big. The instructions say to paint it black as to not show and to reduce heat. I'm not so sure about the reducing heat part. Does anyone know the size resistor that could be added instead of the bulb to bring the voltage down from DCC to the 1.5v grain of something sized bulb? Thanks!
Emman
Tomar hasn't change that design in 20+ years. The reason for the auto lightbulb was not only to reduce the voltage to the 1.5v micro bulb, but also reduce the heat produced by the microbulb so it wouldn't melt the slide film that was used for the drumhead insgnia. That worked well on DC as the variable voltage that ran through the circuit never exceeded 12volts. With DCC there is a constant voltage of about 14-18 volts, which would make both bulbs quite hot. You could substitute the auto light with a 580 or 660 ohm, 1/2 watt resistor and make sure the "slide" is backed by a piece of white styrene.
Better yet, would be to switch to a surface mount Golden White LED and a 2200 ohm 1/4 watt resistor, (both available from http://www.richmondcontrols.com/ (click on LED in the left hand menu) - get the one with the wires already attached, you'll thank me later!). The LED does not develope any heat.
Either way, you can hook them up to the existing wiring you already have.
Jay
C-415 Build: https://imageshack.com/a/tShC/1
Other builds: https://imageshack.com/my/albums
modelmaker51 Tomar hasn't change that design in 20+ years. The reason for the auto lightbulb was not only to reduce the voltage to the 1.5v micro bulb, but also reduce the heat produced by the microbulb so it wouldn't melt the slide film that was used for the drumhead insgnia. That worked well on DC as the variable voltage that ran through the circuit never exceeded 12volts. With DCC there is a constant voltage of about 14-18 volts, which would make both bulbs quite hot. You could substitute the auto light with a 580 or 660 ohm, 1/2 watt resistor and make sure the "slide" is backed by a piece of white styrene. Better yet, would be to switch to a surface mount Golden White LED and a 2200 ohm 1/4 watt resistor, (both available from http://www.richmondcontrols.com/ (click on LED in the left hand menu) - get the one with the wires already attached, you'll thank me later!). The LED does not develope any heat. Either way, you can hook them up to the existing wiring you already have.
One lead then (one with the Resistor cut into it) to each bottomplate? It's a shame Tomar doesn;t sell the drumhead sans all the other stuff then
modelmaker51 Better yet, would be to switch to a surface mount Golden White LED and a 2200 ohm 1/4 watt resistor, (both available from http://www.richmondcontrols.com/ (click on LED in the left hand menu) - get the one with the wires already attached, you'll thank me later!). The LED does not develope any heat.
An LED is polarity sensitive and if your layout is DC controlled, a diode bridge rectifier will need to be incorpoated into the circuit or the LED will light in only one direction of travel. If you wire it backwards without the bridge rectifier, the drumhead may light only when backing up.
For DCC the LED will stay lit as long as power is applied to the track and you won't need the bridge rectifier.
I bought four Tomar drumhead kits about 2 years ago, and they all had been upgraded to surface-mount LED's with 2 K series resistors and 1-chip bridge rectifiers. Maybe Tomar will give you a decent price on those parts.
Mine work well electronically; my problem was putting the rectangular-sign version diffuser plate and sign together and mounting them on the box without having light leakage out the edges. You can't paint the edges black because the paint will get sucked into any air space between the two pieces and ruin the sign. I finally hit on black striping tape sold at automotive paint stores to put on the sides.
Hal