I want to install an NCE "SW9-SR" decoder into my Proto 2000 SW9. I will be installing a "yelo-glo" LED for the headlight. Having read the instructions carefully on page 6 of the instructions, they said to solder the long lead (anode) to the pad on the topside of the decoder, but do not mention what to do with the shorter (cathode) lead.
My question is, does the cathode not get attached to the decoder? seems improbable.
The paragraph pertaining to "White LED" has the following text:
"Solder white LED to the solder pads at the front of the decoder. The long lead (anode) of the LED solders to the top pad of the decoder. Be sure to insulate the lower lead with shrink tubing or line the groove in the locomotive weight with a strip of black tape to keep the LED from shorting to the frame. There is already a 1K resistor installed on the decoder for the LED. (Do NOT solder a jumper at "X")"
There is a pad under the top one where the the anode gets soldered, but the bottom tab doesn't have a pool of solder as does the other one on the top. This leaves me to the question above!
Help!!
Many thanks.
Al
Al,
Yes, you'll definitely need to solder the cathode ( - ) to a solder pad or wire. Logic would dictate that the pad on the underside of the decoder (opposite from where the anode is soldered to) is where the cathode is attached.
Do you have more than one LED?
Tom
https://tstage9.wixsite.com/nyc-modeling
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Tom,
I am using the LED only for the headlight, and the existing 1.5V bulb for the rear light. I was thinking of using the Mike Polsgrove method of employing a 14V bulb for the headlight, but like the idea of the longevity of LED's!
Thanks for your help. I will solder the cathode to the pad on the underside of the decoder.
I successfully installed the decoder and did solder the cathode to the pad directly under the one for the anode. I had to create a small pool of solder on that pad. After that, all went well. This was the first time that I had to do soldering to completely install a decoder, so I was a little hesitant at first, but was happy that everything worked out well!
By the way, I did notice an "aside" note on the instruction sheet regarding attaching the cathode on the backside of the decoder. I just wished they had mentioned that in the main body of the lighting instructions.....it would have made this post unnecessary!
Thanks, again Tom.
-Al
That's terrific! I'm glad it worked.
I really like LEDs for both front and rear headlights. The beam in more focused through the lens than an incandescent and the heat output is pretty much non-existent. (No worries about melting the shell.)
On the aside note, it may have been added to (copied onto) the original instructions after the fact.