# Newb question regarding power taps.



## Shadowracer (Sep 11, 2004)

Howdy all! Well I've been plugging away at my track. 

Its taken a little longer than I had hoped. Back in the early summer, the 1:1 race season kicked on and the little cars went on the back burner for a while. Then in July, chest pains sent me to the hospital, where I was awarded a quad bypass operation  that has pretty much kept me on ice since then.

The good news is, its given me time all the time in the world to work on my table. Thankfully the table itself had already been built so not much heavy lifting. Been going over my track pieces, checking connectivity, joints etc. (sometimes the Tomy track can be a bit rough in that regard...particularly the original non-Racemasters version of the 18 inch curve - yikes :freak:.)

Anyway, I've run into something I don't quite understand, and I'm wondering if the more electronically proficient members of the Hobbytalk faithful can give me some insight.

I've always understood that as far as power taps, the conventional wisdom seems to be one tap per 12-15 joints. However, I laid out my track (photo below) and it all seems to be working quite well. I hemmed and hawed and thought maybe I could get away with 2 power taps. There's 40 joints on the track, and if I put one on the main straight and another at the halfway point, then I should be ok. (we're box-stockers anyway) 

For reference, If I do that, then the taps would be effectively on either side of the yellow car in the photo.

Just because I was curious, I pulled out a multimeter, hooked the power up, and put an elastic around the controller in the wide open position. I got a reading of 20.5 volts right at the power source. I went around the track, and even at the furthest point from the power track, I was still reading 20.5.

Is this a fluke, or am I reading the wrong thing? I would have thought that the further I got from the power, that the reading would go down.

By my estimation, I'm thinking that I'm not losing power anywhere...and that maybe an additional tap is not even necessary?? I'm still gonna put the second one in...already made the power tap track, but just wondering what's going on. 

Also....second question, is there any wisdom about where exactly power taps should and should not be placed? I have a race buddy who swears up and down you can't put a tap too close before a curve or the cars will go flying. That just doesn't make sense to me...its not like the cars get a surge of power when they hit a power tap...or do they?

Anyway, below is a photo of the yet to be named "Circuit de Shadow" I'm quite happy with the layout and the way it runs. I wanted it fairly simple, devoid of spaghetti esses, and with lots of room for grass, pits, billboards etc. The motif will be sort of a cross - a saturday night short track, road course style.

Thanks for watching!


----------



## cwbam (Feb 8, 2010)

just an opinion
The less amps you have, the more power taps you may need.
So if you got 20v 10 amp power supply, 1 tap may work.
If you have 2 20v wall wart 3 taps maybe nice.


----------



## Steelix_70 (Feb 19, 2012)

I would think buy just looking two power taps would be good. As in my track I'm working on yes the volts where good with one tap, but the cars would slow up, as I hooked up all the taps it would not and just run better all the way around.


----------



## alpink (Aug 22, 2010)

in another thread, hornet, describes a light bulb thingy he uses to help check voltage around the track. it seems without a draw, the voltage will appear the same all around the track. but, if you use the lightbulb trick at the point where you want to measure you will get a more accurate measurement of usage and draw characteristics.
regarding where to put taps. let us think about what it does. it provides another place to access the power, so the closer you get to it, the more power will be available and as you are going away from it, power will seems to fade a little. 
there won't be a surge like happens when one or more cars deslot allowing the remaining car(s) to have more voltage/amperage than they had just before the deslot.
since I cannot back any of this up with verifiable data we will just have to say it is my opinion freely shared.
and we all know about opinions! LOL


----------



## Shadowracer (Sep 11, 2004)

Well thank you for the responses guys. I got a tip about using the continuity checker on my multimeter, so I'll try that first.

Barring that, I may try another version of the "lightbulb trick" except with a slot car. (ill have to try that when my son comes over and I have the extra set of hands.)


----------



## Boosted-Z71 (Nov 26, 2007)

With the load tester you can find your bad / weak areas really fast

Here is the thread Al was referring too

http://www.hobbytalk.com/bbs1/showthread.php?t=340565&highlight=test+light&page=4

Boosted


----------



## NTxSlotCars (May 27, 2008)

I power this Tomy track using only the power tracks on the front straight away.










When I use a power supply, I really need a power tap half way through on the third straight.
When I use batteries, I don't need a power tap, unless we are running high downforce cars.
Bottom line is I could probably use a power tap half way through to make it better either way.


----------



## Hornet (Dec 1, 2005)

Just a heads up,a bad connection only gets worse the more current you feed through it.
It heats up,and the resistance goes through the roof.
Batteries or high amps will only cause your bad connections to get worse over time.
A bad connection generally is not self healing,it only goes downhill the older it gets,kinda like us old farts,lol


----------



## Shadowracer (Sep 11, 2004)

Thanks again guys. BTW great setup you got there North Texas. Slot cars AND racing stuff up on the walls. :thumbsup:

Hornet, check your PMs.


----------



## Hornet (Dec 1, 2005)

Done ,answered,lol:wave:
Rick


----------

