Digital Slot Car Power Distribution
Introduction: Digital Slot Car Power Distribution
Ever built yourself a large slot car layout and found that the cars just don't seem to have the same performance? Or do you hate it when your races are interrupted by the cars stopping because of bad joints? This Instructable will show you how to get your digital race track running faultless.
Please note that this is for digital track, which is where you can race with multiple cars in the same slot. If you wish to do this for systems which run one car per slot on analog controllers, there is a few notes at the end to help you modify it.
Supplies
You will need the following tools -
* Soldering Iron
* Solder
* Cutters
* Strippers
* Screwdriver
* Ruler
You will also need the following components (Part numbers from www.DigiKey.co.uk )
* Matrix or Strip board (any will do) x1
* PCB standoffs (M3, any length or type will do) x4
* 3 pin PCB mounted header - WM2745-ND x5
* 3 pin connector housing - 900-0022013037-ND x5
* 22-30awg Crimp - WM1114-ND x10
* 2.5m Red Hook up Wire - 2200/26RD-100-ND
* 2.5m Black Hook up Wire - 2200/26BK-100-ND
* Epoxy Glue (Any will do)
Step 1: Building the Board
The construction of the board is simple. Solder the 5 headers in place, then if using matrix board, solder the board to create tracks linking the outside pins in parallel lines. In strip board, ensure that the strips will connect the outside pins of the headers. If you have a multimeter, it pays to check to ensure that all of the number 1 pins are joined, and all of the number 3 pins are connected. There shouldn't be and connections made between any number 1 and 3 pins or it can damage your power base.
This gives you 5 connection points, if you wish you could add more. The next step explains how and why this works!
If you don't know how to solder then please check out this Instructable https://www.instructables.com/id/How-to-solder/ (Thanks <PERSON>!)
Step 2: The Science
Without diving too much into details of how resistances work, I will give you a simple explanation so you know why and how this works. If you want a more detailed explanation then please do look up <PERSON>'s law and <PERSON>'s law.
Fig.1 shows a circuit representation of a slot car track. Each of the resistors represents a joint in the track. No matter how good the connection, there will always be a small resistance here, which hinders the flow of electrons (electricity). Every resistance causes the voltage to be a little bit lower, so when the car is further away from the power base, it has less voltage to power it. This leads to poor performance from the cars, and when multiple cars are on the track this effect is even greater, possibly even stopping the cars.
If there are then two breaks in the track, this section between the breaks will become a dead zone and nothing will run at all. 611
It would seem to any logical person that what is needed is more power bases.
Fig.2 shows a circuit with our power distribution system fitted. Now we can see that we have far fewer resistances in between each power 'tap'. This means less volt drop so our cars get more voltage, and that means more performance. Multiple cars racing will then be able to run better so your races will run smoother with less track issues. Any breaks in the track are also far less noticeable as instead of two breaks over the whole track, there must be two breaks in each section to have an effect.
Step 3: Preparing the Wires
Now its time to get the interconnecting wires prepared. First, cut a red and black wire of about 10cm for each piece of track we are going to 'tap'. These will need to have 5mm of insulation stripped away so you can twist and tin them using a soldering iron. There is an image showing me tinning a wire above.
Next cut a red and black wire for each tap. I would suggest 2 meters but if you have a bigger track than 4 meters then you may need them longer. Once cut, it makes a tidier job if you twist these together. I did this by holding one end in a clamp, and clamping the other in the chuck of a battery drill. I then pull it tight and operated the drill until I had twists of about 1-1.5 per cm. 933