# Timming help



## shocker36 (Jul 5, 2008)

I have a 4 lane Bucktrax Scorpian that is need of a timing system it has reed switches with a parallel port wiring harness but, I would like to switch over to diodes and a light bridge. Im using individual power supplies to run the track which is working and I downloaded some free track software. What I need is some expertise in wiring or pointing me in the right directions for parts and what not. I live in the Chicago land area if anyone wants to come out and help I cant offer to much in the way of money but beer, brats, and slots I have plenty of any help would be appreciated.

Thanks 
Brian


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## Boosted-Z71 (Nov 26, 2007)

As for parts you need the following from Radio shack
Ask the clerk for RS-276-145 Photo-Transistor 

for the Light gantry, get RS-276-143 high output LED's, & RS-271-1115 for the 470 Ohm ½ watt resistors & you will need some type of a 12 volt transformer to power the LED's, something with minimal AC ripple works best. I have used any small 12-14 volt cordless chargers with good results. 
You will need a 25 pin D Sub male connector & hood to get to the computer & a Rj45 connector & socket if you want to do your setup like the web site. 

I have used the free software from his site and had good results, after I got things lined out. One of the biggest problems I had was with the light bridge, some LED's are not strong enough to give you the light you need. The above mentioned parts work very well together for timing. Play with the height of the timing lights to get the best coverage, I have found something near 4 - 4-1/2" above the track surface works well 

Here is a link to the HO Slot car web page with wiring info

http://www.hoslotcarracing.com/ - Look for Lap timer info I use the Printer port config.

Good Luck 

Boosted


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## SDMedanic (Apr 21, 2011)

Not overly crazy about the Radio Shack LEDs. With the Trakmate IR sensors I had to run those LEDs close to 100ma to get them to be reliable. This leads to shortened life. The RS LEDs are also 940NM output. The Trakmate sensors at least don't like that wavelength. I have had excellent results with 850NM LEDs. Those I can run reliably at 20ma with up to a foot between LED and sensor. With four inches between LED and sensor the sensors are fully saturated. Send me your addy and I would be happy to send you some.

I live in the Chicago area and would be happy to get you up and running.

There are two schools of thought. Running the LEDs in series or in parallel. Your design wires the LEDs in parallel and for that you need a 1/2 Amp, 12V power supply. Typically running a wall wart near its rating lowers its output and you have to adjust the dropping resistor for the actual output of the power supply. Wiring the LEDs in series reduces the power supply current requirements to 20-50ma. It also reduces the heat generated by the LED dropping resistors. 

I am never crazy about free software and usually you get what you pay for. Trakmate and Slotrak are both reasonable and give excellent results. The Trakmate sensor cable is also worth buying.


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## Rolls (Jan 1, 2010)

For my money, it's almost as easy to wire 2 or 3 LEDs in a clump per lane as it is to do 1 per lane in the light bridge. Gives a lot more photons on the receivers in the track and makes alignment more forgiving. 

Hope it helps!

Rolls


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