[?] Hi there everyone out in Model Railroad Land! I am just wondering if anyone can offer a workable solution - I mean workable - NOT IMPOSSIBLE! Here’s the problem. I have an Athearn Genesis SD 75 I and I have installed a Command Control receiver (a RAILCOMMAND receiver) that is the same size, etc. of a DCC receiver but is NOT a DCC receiver it is an analog type of Command Control receiver, and the locomotive runs A-1. However, Athearn is STILL so very OLD Fashioned, using regular 1.5 volt light bulbs instead of L.E.D.'s and plastic light pipes to direct light to the headlights and ditch lights. These regular bulbs pull too much AMPERAGE through the receiver and end up, very quickly, burning out one of the transistors, I believe that’s what they are called, on the receiver. I had installed two 680 OHM resistors in line for each pair of these 1.5 volt bulbs, so that the voltage would be O.K., but I never thought about the amps. I am NOT an electrician or electronics guru, but I have picked up a small amount of knowledge working with these Command Control systems, but I still have lots to learn. Needless to say, these 4 bulbs burned out this tiny transistor very quickly (in about 2 seconds). The rear two bulbs are still lighting, but I fear that they will not last very much longer. I saw something about surface mounted L.E.D.'s so I went to the local Radio Shack to see if they had any. The clerk looked at me as if I was asking for something from outer space. So much for that, SO, ONE of my questions is does anyone know where I can get these Ultra bright S.M.D.'s? I figure that if I can get some of the really small ones, that I could perhaps install them in the headlight spaces and even in the ditch lights. Barring that, then we come to the BIG question - can anyone offer a suggestion as to how I can install L.E.
Oh nasty, Athearns WORST model. I have three of those and they area all nightmares.
Which one? power1, mini, kat1, skinny, ATH1 or one of the older ones??
Since the original “kato” reciever kits (about 1991) CVP recievers have been digital technology. That is why the programming traces one has to cut inorder to program them to a channel number are 512, 256, 128, 64, 32, 16, 8, 4, 2, and 1.
Yes, I know that transistor. I burnt it out too, but it wasn’t because of the light bulbs it was because I shorted it out during installation.
Two in series for a total of 1360 ohms, or two in parallel for a current carrying equivalent of 340 ohms? Are you running your Railcommand at a normal voltage of 17.5V to the track? Using the 340 ohm figure and assumptions it sounds like this should only be passing 51 milliamps to the light bulb. That should not burn anything out. Might want to recalculate.
[quote]
the BIG question - can anyone offer a suggestion as to how I can install L.E.D’s, or some method of installing illu
since the DCC system may be able to handle 1.5v dulbs, I don’t think the manufacturers anticipated someone switching to a different train control, so thats how its designed. Running light tubes is prolly an efficient manufacturing method. A different design in manufacturing might raise the cost. But some of us modelers may not care, but I thik the manufactuirer is looking for a good selling price point so the product sells.
I think Walthers has the surface mounts in their catalogue actually. There is a manufacturer /dealer specializing in this area.
Hello Texas Zephy, Thanks for your input. I’ll have a look at the Walthers catalog to see if I can find the S.M.D.'s. I used a Kat-1 (NOT a Kato) receiver. I should also clear up one point, the 680 Ohm resistor was used for 2 lamps ONLY, not all 4 . I mis-spoke when I said “in line”, they were actually parallel - 2 lamps on one resistor and 2 lamps on the other, but they had to be soldered to the proper spots on the receiver to work (one on one spot and the other on the other since polarity was not a problem here). The lamps did work for the first 2 or 3 seconds, then stopped. After, I checked the lamps, individually, with a 1.5 volt battery and they were O.K., so that is when I assumed it was the transistor that had burned. There may be modellers who like the weak yellow light of the bulbs, but not me, I like headlights that one can actually see - ultra brights. The real locomotive headlights are quite powerful and bright and that is what I desire to emulate. I had heard, I honestly don’t remember from where, that there were some fellows who had devised a method of getting illumination into the ditch lights that was not a major struggle and that is what I am hoping to find out how they did that, but I’m open to any reasonable idea or method of achieving this end. Perhaps the idea of micro bulbs is the answer. I will try to get some and wi
Excellent choice. That is actually what I meant. It is one of my favorites. I edited my post above before I realized you had already read and responded.
I just found the CVP F.Y.I. from Fall 2000. It talks about heavy current on lamp output. It starts by stating that each lamp output should be able to drive 100 mA. I can’t believe any 1.5V lamps draw more than that. Have you measured the current draw on the lamps when using the battery? Now I am currious. The article goes on to talk about creating 12 V power using only two external components (A p-channel MOSFET like ZVP3310 and a 10K pull up resistor). It then shows how to add an external bridge for loads greater than 1 amp., and then how to make a bigger “switch to ground” (although I don’t understand what that means). My copy is bad in that it printed off the edges/bottom of the page, but I am certain Keith would not mind me sending you a copy if you want.
Anyway other stuff - the KAT1 installation flyer I have here says to use 470 ohm resistor for LEDs.
I believe if you examine the surface mount transistor with a 10x magnification you can see a tiny dot if it has burnt out.
Do you have King Soopers stores in your area? I found a string of 50 LED christmas lights that work great for headlamps. Upon disasembling I found they were 3mm rather than the 5mm I was expecting. They are not that nasty blue color but a very pleasant day-glow. They are bright enough it hurts to look into them f