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Electrical Work - My Controller
For this layout, I needed independent control of 3 separate blocks—The 2 mainlines, and the yard. I couldn’t find any commercially available 3-way controllers on the market, so I decided to build one, as opposed to buying3 different controllers, which would ultimately have cost more (although make no mistake: This was not rock-bottom cheap).
Here’s a list of the materials used:
1X Plastic box (about $10)
3X PWM DC motor controllers from Amazon ($9 each)
3X DPDT switches for controlling direction (>$1 each)
4X Barrel Jack Connectors (female) for input and output ($0.75/pair)
3X LEDs for indicating board power ($2.50 each)
1X Power supply ($15)
I started with a good sized plastic box I got off eBay. I don’t remember the exact dimensions, but it was just big enough for my purposes. I drilled 3 holes in the top of the box (for the potentiometers), 6 in the back for the barrel jacks (3 for output, 3 for input, though I ended up using only 1 input jack). In the bottom, I drilled 9 holes (3 for each circuit board).
I placed some foam window trim on the bottom, to prevent the tabs on the underside of the PWM boards pressing against the plastic, and then screwed each of the controllers in using M2.5 nuts and bolts. Following that, I used 2-part epoxy to secure the barrel jacks in their holes, and ran the wires to each of the controllers.
3 more holes were drilled in the top for the DPDT switches that would be used for reversing polarity. The two “motor” wires on the PWM controllers were soldered to the center tabs on the switches, and two short wires formed an ‘X’ to connect to the outer tabs. The output wires were connected to one set of outer tabs, and connected to the output barrel jacks.
After that, I soldered the LED’s to the underside of each of the PWM boards and drilled an additional 3 holes in the top. These lights come on when the boards get power, which is supplied by a 12V, 3.3A laptop charger. This power supply seems to have plenty of power for running numerous locomotives off all 3 controllers at once.
It all sounds, and looks, rather complicated, but it was actually very straightforward to wire and works very well. The total cost came out to somewhere around $110 including shipping (because the supplies were acquired from a variety of sources, shipping was a significant part of the final tally), while 3 new pre-built DC throttles would run you back $150 before shipping, and take up more space. Its up for debate whether the savings is worth the effort of putting this together, but I had fun doing it, and the controller fits better for the compact space its being used in.
I don’t have a high-quality DC controller to compare it to, but it works far better than my starter set Bachman controller, which shuddered at the thought of running more than a single locomotive with a medium-sized train (I once ran 2 locomotives with 20 cars and could smell it melting its own plastic). I have run 5 locomotives at the head end of a 30-car train with just one of the PWM controllers with no problem, and slow-speed control is phenomenal, even with older locomotives.
