A Simplified Driver Station
v In another article, I showed how to make a complete driver station with multiple functions. Here, I present a simplified version of such a driver station with only direction reversing and an option for brake sensitivity adjustment. The following is hopefully sufficiently clear and self-explanatory for anyone to try to build it. Should anything be unclear (or wrong) please contact me and I'll try to help as much as I can.
v Functionality and operation:
o Direction switch (top left): changes the direction of travel of a car on the track for that lane (reverses the polarity of the DC voltage at the track, but does not require any polarity change at the controller). Yes, this way, cars on different lanes can travel in opposite directions
o Brakes Adjustment (top right): Potentiometer/Rheostat allowing adjustment of brakes sensitivity.
o Controller hookup (middle and bottom row): 3 female banana plugs along with 3 contacts (below the banana plugs) for those controllers with alligator clips.
o Track Power: two banana plugs on the left of the box for the wires coming from the power supply
o Power to track (right of box, not shown on picture above): two banana plugs for the wires going to the track. Red will go to the right rail, black will go to left rail (when seen from top of track)
v A note on the controller hookup: I am showing here a box that offers two options for controller hookup, either banana plugs or alligator clips, mostly because that is what I use and they are very standard. You might want to tailor this to your own needs, depending on the type of controllers you use (Ninco or Scalex jacks for example). Also, if you prefer, for alligator clips, you can replace the banana plugs I use (although these are great contacts, as they are nickel plated copper) with any stubs and/or screws you want (for example as offered by professor motor. Part number PMTR1075, itÕll cost you more).
v Here is a picture and the list of components, listed with their source, their part number, and their price. Most of these can be found at any electronics retailer and I am pretty sure that if you spend time digging, youÕd find most of the stuff listed cheaper somewhere else.
|
91F3934 |
|
||
|
DPDT switch for direction |
MTS-8 |
|
|
|
White Banana jack |
BJW |
|
|
|
Two Red Banana jack |
BJR |
|
|
|
Two Black Banana jack |
BJB |
|
|
|
White Banana plug, solderless |
81N1187 |
|
|
|
Red Banana plug, solderless |
81N1188 |
|
|
|
Black Banana plug, solderless |
81N1189 |
|
|
|
Resettable fuse, 1.85 A |
92F9123 |
|
|
|
Resettable fuse, 1.1 A |
|
||
|
KNB-123 |
|
||
|
Rheostat, 15 Ohm, 15W |
RHE-15 |
|
|
Total |
|
|
|
v About the components and prices above:
o A cheaper alternative to the box used here is part number PB-3P at http://www.circuitspecialists.com/, only $1.98. It is just a tiny bit smaller but everything will still fit in there easily, especially without the brake adjustment potentiometer. I do like the box I selected here because it has side-mounting brackets, making it really easy to integrate anywhere on and around the track, but yes, it is a bit on the expensive side.
o The 15Ohm, 15W rheostat is way overkill but is actually cheaper at AllElectronics than other alternatives. If you prefer, you can use any wire wound potentiometer from 10 to 25 Ohms with at least 5W (for example, see digikey catalog page 1009, more expensive than that rheostat but also easier to find). I must admit that I am using wire wound potentiometers (since I had some left over from another project) but the rheostat should be just fine.
v Also needed for this project are a Dremel tool (or equivalent to cut plastic), a power drill, wires (14 gauge or 18 gauge, black, white, and red), and a fine tip soldering iron (0.7 mm diameter tip, 20W is fine)
v First, we need to cut all the holes in the box for the various components; that's where the Power Drill comes into play. YouÕll need a 1/4Ó hole for each of the three bottom holes for the alligator clips contacts and the top left hole for the direction switch. YouÕll need a 5/16Õ hole for each of the banana plugs and a 3/8Ó hole for the potentiometer. YouÕll also need 4 holes on the side of the box for the banana plugs for the track power supply and track connections.
v Next step is to prepare the banana jacks to be mounted on the lid (face plate). For this, you need to get the Dremel out and cut about 5 mm of the plastic, all the way to the beginning of the thread. The picture below shows all three plastic housings, with the black one having been cut on the right hand picture.
v Then you need to solder some wires to each of the contacts of the banana jacks. Do not be afraid to use a lot of heat for that, remember to heat the metal part of the jack, not the wire.
v The next step is to mount all the components on the front and sides of the box. The top two pictures below show a top and bottom view of the lid of the box.
v Next comes the Schematic wiring of the driver station. You need to make all the connections shown below inside the dashed outline of the box (driver station enclosure). Do not forget the diagonal wires on the direction switch.
v A picture of the inside of the box showing the wiring.
v Tips and hints:
o Use 14-18 gauge wires for all the wires, obviously 18 gauge is smaller and easier to solder. 14 gauge is really only needed if you use hot motors at more than 3 Amps.
o Direction switch: do not forget the two diagonal crossed wires. When the switch is set to the right, the lane will be wired in the so-called "positive polarity", i.e. the right rail, when viewed from the top, will be at the positive voltage.
o A word of caution about the resettable thermal fuses: I selected these values because they are suitable for my track where I run mostly Artin 1/43 stock motors. If you run really hot 1/32 or 1/24 motors (such as the little ripper, cheetah, 16D, etc É type), you might have to increase the Amps values for these fuses. For convenience, here is a link to the catalog page with other such switches of different Amperage. Remember the Amps value quoted for these fuses is the value of the current they will hold continuously, knowing that they will trip when the current actually exceeds the quoted value, typically twice that value.
o If you do not use the brake sensitivity adjustment, connect directly the red banana plug and jack to the negative of your power supply, i.e. the black banana plug on the left of the box.
v The result: 2 very nice and useful driver stations
Last Update: 8/19/06 Drop me a note