Lap sensor

[Czar]

What do you use to sense laps on your race track? I had two Carlson tracks, but neither is working anymore. What can I use to recognize that a car has passed the start/finish line?

[RichD]

The most commonly used sensors are IR detectors and dead strips. HO tracks sometimes use magnetic reed switches and I have run on tracks that used photoresistors or microswitches. Each type of sensor has its advantages and disadvantages. With IR detectors you need to use matched IR emitters and those need a power supply. A car that is not in the slot when it passes over the detector will trigger a count. The Carlson system uses emitter/detector pairs that look across the slot and are triggered by the car's guide flag. If the guide flag is too shallow or is transparent to IR counts will be missed. Dead strips are the simplest detector, but precautions need to be taken when they are connected to a computer and they only work properly in one direction. If you want to be able to run your track in both directions you would need to add some reversing switches to the circuit. Dead strips will only read if the car is in the slot. Magnetic reed switches require a fairly strong magnet in each car. If a car happens to be airborne when it crosses the switch a count will be missed. Photoresistors work much like IR detectors but they need a strong light source to work whereas IR is not visible to the naked eye. Microswitches are triggered by the car's guide flag. Since different cars might have a shallower or deeper guide flag microswitches can be difficult to adjust.
You might try to troubleshoot your Carlson sensors. Did all of the lanes stop working at the same time? If that is the case the emitters may not be getting any power and you would need to check the power supply and the connection to that. If only one lane is dead there could be some dirt or lint blocking the emitter or sensor. You could try a blast of canned air. If an emitter/sensor has failed you can buy a replacement. On another slot BB there is a forum for the Carlson system, that has been inactive for a number of years.

[HomeRacingWorld]

Still using the Trackmate infrared. Overhead style.

[vonsirius]

I simply use a Carrera lap counter, connected to a power supply to avoid batteries (it´s easy to do), works reasonably well.

[slothead]

Dead strip wired directly to a wireless mouse to create a left-click every time a car crosses it. Since I got the polarity right, it's been flawless. Best aspect for me is I don't have to connect my PC to the track, but I'm not sure if any current race management or lap counting/timing programs can be configured so a mouse click triggers a lap count. I use a split-lap timer program to create a log that I then process in an Excel spreadsheet.

Yes, I am a nerd.

[buspor63]

Like Slothead, I used a PC mouse and this program to time laps. The program is basic, but effective.

http://pcslotmouse.mygamesonline.org/

Here's the complete thread.

http://www.slotforum.com/forums/index.p ... 770&page=1

[slothead]

Anyone thinking about using a dead strip, no matter what it connects to, should check out the pcslotmouse link to see how easy it is to create a dead strip above your existing tape or braid and not have to disturb what's already there. This way even if it takes a bit of doing to get the dead strip working as desired, the track will still be fine.

If using the PC mouse method and with a wireless mouse there's no way stray voltage can damage your computer. You could fry the mouse, but they are cheap and easily replaced. IMPORTANT MESSAGE: no animals were injured in the creation of this post.

buspor63 - do you know if the base program from which the executable file was generated is available anywhere? When I have free time I'd like to work on adding additional features if it was okay with the original creator.

[RichD]

If you want to connect your sensors directly to a computer you would need one that has serial or parallel ports. Newer computers only have USB ports, so a USB mouse would be one way to go. If you are running cars with braided pickups there is a type of dead strip of sorts that can't endanger your computer' serial or parallel ports. The connection would look like this:



Computer ports do not like having a dead short applied across them, hence the resistor.

[historiceng]

[RichD]

Trackmate and Race Coordinator will call out your lap times. Most of the lap timing software programs will save your fastest lap, so you don't have to keep one eye on a display. I did forget to include smartphone apps and apps that use a webcam connected to a computer. Another thing that I forgot to include is a wireless dead strip system called exoSlot. The dead strips are connected to a transmitter. The receiver is a USB device that plugs into your computer.