Edit post

Edit your reply below.

Post Body
Enter your post below.
Hi Phillip I don't know what scale you model or if you are using DCC or DC, however I found and have used a very small voltage regulator from Digi-Key ( http://www.digikey.com ) part #TK11625CT-ND (100 mA, 2.5 volt output). Absolute maximum input votage is 16 volts. Most HO scale DC systems are about 14 volt. You will need to connect the voltage regulator to a bridge rectifier, part # DF02MGI-ND. The voltage regulators are in a TO-92 package. With the flat side facing up and the pins pointing to you, the right pin (#1) is the positive (+) output. The center pin (#2) is common ( - ) and the left pin (#3) is the positive (+) input voltage. The bridge rectifier is connected between the motor, or any voltage pick up point, and the voltage regulator. Both leads from the power pick up connect to either pin marked ~ on the bridge rectifier. The + pin on the bridge connects to pin # 3 (+ input) on the voltage regulator. The pin marked - on the bridge rectifier connects to pin #2 (common) of the voltage regulator. Pin #1(+ output) of the voltage regulator connects to the anode ( long pin) of the L.E.D. and the cathode (short pin) connects to pin #2 (common) of the voltage regulator. Total cost per unit is about $2.20 less L.E.D.s and wire and printed circut board (optional). Of course if you are using DCC, forget the above and just use a resistor connected to the wire for the headlight on the decoder. To calculate the value for resistor subtract the L.E.D. voltage from the track voltage and divide that by the current draw (in milliamps). The formula is written as V in - V led ........................................I led ..................... G. p.s. To prevent a short curcuit, cover all exposed terminals with heat shrink tubing or liquid tape after you test the curcuit. Remember, anything that uses electricity generates heat to some degree. Therefore keep components away from any plastic in the locomotive.
Tags (Optional)
Tags are keywords that get attached to your post. They are used to categorize your submission and make it easier to search for. To add tags to your post type a tag into the box below and click the "Add Tag" button.
Add Tag

Update Reply

Subscriber & Member Login

Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!

Model Railroader Newsletter See all

Sign up for our FREE e-newsletter and get model railroad news in your inbox!

Subscriber & Member Login

Edit post

Post Body

Tags (Optional)

Subscriber & Member Login

Users Online

Search the Community