I placed a Lenz Silver decoder in my HO Proto 1000 F3-A. The decoder seems to work correctly, I have no problems moving or anything. My problem is that whenever I push the light switch for the loco the light comes on for a split second then goes off. I can't get it to repeat this unless I either remove the loco from the track or shutdown the power and power up again. Does anyone have any ideas as to why my light isn't working? It uses an LED. I've tried switching the blue and white wires that go to the LED but that didn't seem to make any difference. Thanks in advance
make sure your system and your loco are set for the same speed steps. If they aren't, your light will act exactly as you describe.
Ray, I thought we were on to something here. But I've went back through my setup for both my NCE setup and for decoder setup, they both are set to 28 speed steps. I'm at a loss for the problem. I'm gonna try another LED once I can find someone that sells them. I don't know what else to try.
Light goes off after a split second, and won't go again until power cycled? That sounds most to me like the decoder is 'sensing' an over-current on the accessory output and disabling it to stop from frying itself. I'd check your wiring and resistor value on the LED; if either of the blue or white wire are touching the shell, that's bad (also any circuit boards holding the LED, if you had to bend or fiddle something to get it to fit, it might now be shorting) Does the engine have lights on the other end? Do they work? Also, check the docs on the decoder where it mentions LEDs and Lamps, I know a couple (NCE?) have different CV settings for a lightbulb verses an LED. Resistor value is a bit more iffy, depends on volts, decoder, LED, how it's all wired... Hopefully the decoder docs offer a value (I tend to stick with the LED circuit used before I put in a decoder; but I'm N - do we have more LEDs and less little bar heaters?) Finally, try resetting the decoder and starting afresh - often works wonders.
Thanks for the responses guys. I have tried resetting the decoder, this evidently wasn't the answer though. I'll double check the possiblity that it could be shorting out. The Loco does not have rear lights. I also use the Lenz Silver in my U23b (with front/rear lights) and all works fine, this is another indication that I have the speed steps correct. I'm at a loss, I'm gonna place a new LED in it and see if that corrects anything, then I'll probably phone Bruce at Litchfield to see if he has any idea. Thanks again for your help.
I was talking to some guys at the LHS and they thought that the loco may be putting out more voltage than the LED can handle. I may just switch to a grain of wheat bulb that can handle the voltage. I haven't tested the loco yet to see just how much voltage it's putting out.
Jeff, did you add a resistor to the led? Did you add the led. Most led need a resistor to work properly.
Sounds like a resistor problem to me. An LED is a current driven device so voltage should not be a problem as long as the resistor is good. You have to have a resistor in series with the LED for it to function properly.
John/Russell, To answer your questions, No, there was no resistor (out of the box) as far as I can tell. The LED was simply connected to the pc board. So you think that if I add a resistor the LED will work fine? Just wondering why the Proto 1000 would come like that, why it wouldn't have a resistor installed from the factory? I'm a novice at this, can you point me to an online tutorial for adding a resistor?
I am not familiar with that particular decoder board. Perhaps there is a tiny surface mount resistor installed but it is shorted out or defective in some way. A tiny solder bridge or a piece of conductive debris could be bypassing the resistor. A quick fix could be cutting one of the leads to the LED and bridging it with a resistor (somewhere between 500 and 1000 ohms) Or just return the locomotive to the manufacturer as it appears to be defective.
Most newer locos, at least in N, have a little PCB with the LED and a resistor on it, and this connects to the chassis and the motor. What happens next depends on the nature of the install, if it was wired or a plug or what, and may explain where the resistor went. Since you mentioned wires, I'm going to assume you hard-wired the decoder; meaning the warranty on the engine is void. No matter. A quick google didn't find anything valuable on decoder installs and resistors. Best website: http://home.neo.rr.com/mrwithdcc/primer.html. The summary is that the blue wire goes straight to the LED anode, and wrap the connection somehow (tape is okay, heatshrink is better). The LED cathode is connected to a resistor, again heatshrink, and the resistor to the white wire, more heatshrink. You could put the resistor on the other leg, I don't think it really matters. Enough heatshrink or tape covering everything metal really reduces the chances of a short. (aside: normal electrical insulation tape is no good for using on motors for DCC installs. It gets hot and stops sticking, allowing shorts. Use Kapton Tape (yellow). Normal tape should be fine for an LED. they don't heat up ) The Cathode of the LED is identified by two or three methods: Longer leg (until you cut them) Flat side on the LED housing (or absence of a ridge) If you can see through the lens, the cathode has a big triangular piece of metal holding the silicon blob, and the anode only has a little stick As an acid test, the LED + resistor without decoder should light up when placed on the rails or programming track, either way around. An LED without a resistor will probably glow very brightly and then stop glowing and die. Resistor value? I have no idea. That website suggests 560 ohms, and my excuse for bad math says that shouldn't be far wrong.
I didn't have to hardwire the decoder. The Proto 1000 had a pcb that you remove (maybe it's the one with the resistor), and then you can plug the decoder directly into the 8-pin NMRA plug. Attached is a pic of the little pcb that I removed, could that be where the resistor is located?
Wow. NMRA plugs. You HO guys have all the luck. Bingo. There's a resistor, labelled R1 next to the pins. Either you can salvage that resistor or buy a new one, and either splice it into a wire on the decoder or onto one leg of the LED, and that should fix all the problems. What a cute little circuit board. I wonder why it has so many diodes?
That's a resistor immediately to the left of the 8-pin plug. It's labelled R1. Being a generic decoder install, it appears you will need to add a separate resistor inline with the LED. The original board probably used R1 for the headlight LED.
Jiminy....like the guy at the LHS told me on Tuesday. You learn something new everyday. Thanks for all your help guys. Now all I've got to do is find out how much voltage this baby is putting out and what size of resistor I need.
