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Discussion Starter · #1 ·
1. Hey there, are there wall warts that provide enough juice to power 4-6 lanes? I hear that each plastic box car usually uses about an AMP.

2. I don't understand that the lable says 12V car, but the Scaley power pack kicks out 19V I think without load. Is this saying that with expected load the car needs at least 12V / not more than 12V?

3. If I were to doctor a power supply and power all four-six lanes with it would I need a PS with more voltage OR could I get away with a roughly the same voltage but with, say 5 amps? (If such a combo were possible)

4. If a PS is running 5 Amps and I am only running a single car at the time, am I hurting/killing the car's motor?

...Or do I just need to take a year off and become an electrical engineer?

Thanks MUCHO

-Maltese
 

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the latter! lol.

Basically a standard scalex wall wart is nowhere near powerful enough to power more than 2 lanes. Most people find a hefty single unit for both lanes or go for a single scalex transformer (black box away from the wall) however being as these are some what now antiques they will either be knackered or expensive or tied up with other useless junk.. I mean track etc.

At Wrexham club we run 2 of these per lane and well, 2 of 8 are definately kaput, 2 of 8 buzz like a swarm of mopeds going through a tunnel and so that leave 4 that are ready to go bang which should be fun watching. However we wont be doing that as we have just bought two brand spanking new 5amp 0-20volt variable all singing all dancing transformers, albeit not cheap but exactly what we were after - roll on next club night.

Saying that were closed this monday due to electrical problems


Inte
 

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Premium Member
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547 Posts
so inte
the red glow over wrexham will be dim on race nights
as you draw all that power into your transforms
will the national grid cope i wonder

see you sunday

DR STICKY AND TRIBE
 

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Al Schwartz
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The Law: (Ohm's, that is)

E (voltage) = I (current, amps) X R (resistance)

Thus, the amount of current drawn by a slot car will be determined by the voltage applied and the resistance of the motor ( + pick-up, rails etc)

In other words, the only issue is the capability of the supply to provide the current that the motor is attempting to draw - less is not good - since the resistance is fixed, you can see from the equation that if the current drops or is limited, the voltage must drop - and the car goes slower - more doesn't matter - the motor will only draw enough current to satisfy the equation*

In simple terms, the answer to one of the questions is no, you cannot hurt a motor by attaching it to a power supply that will provide more ( 5X, 10X...1000X) current that the motors demands*

EM

* there is always an exception - the effective resistance of a motor is that of a running motor. If the motor is stopped or stalled, the resistance drops dramatically and, for a given voltage, the current increases. In this case, a wall wort might not have enough power to damage the motor, an automobile battery will vaporize it!
 

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Graham Windle
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EM is right in what he says , but the thing that will kill a motor is ac ripple poor quality psu's regardless of vots and amps they might out put will soon cook a dc motor if they are allowing ac ripple
 

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Al Schwartz
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Yes, ripple can be a problem - a good regulated power supply will have low ripple. Alternatively, you can just attach a big capacitor, e.g. 2000 mfd, 25 volts, across the output and that will drop the ripple enough to protect the motor.

EM
 

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All those replies are right. They are just too spread out over too many posts


1) No wall warts are able to power that many lanes. A wall wart really can't power one lane correctly (See GRAH1s comment on AC ripple)

2) Scalextric has a little different set up than others. The wall wart puts out about 18v AC, not DC. The track power piece converts the AC to DC and knocks it down to 12v in the process. So if you get a good DC power supply, do NOT use the standard track piece to distribute the power to the lanes. It'll fry eventually and it'll be knocking down the output.

3) This one is more of a personal thing with me, others will disagree. I like 5 amps per lane but I use a 3 amp fuse in each lane. This is where my mythology comes into play. With 5 amps per lane you will at no time max out the power supply so ripple will be rare and the thing will work as it's supposed to for many years to come. The three amp fuse is to protect the lane AND the car in case there is a short. Stuff happens so always fuse individual lanes as well as the primary power input. If your car momentarily pulls more than 3 amps the fuse won't blow. It isn't until you pull more than 3 amps for like a second or two that they blow. This allows you to run higher draw motors while still protecting the track. In real world terms, any 1/32nd scale motor that pulls more than 3 amps consistently probably shouldn't be used on a plastic track anyway, it belongs on a routed track with batteries. Again, this is just me and my way, some will agree while others disagree.

4) Even after all I've written above I'll have to still say a 5 amp power supply will work OK with more than one car. It's just that none of the cars will be operating at their peak performance. Many people use 5 amps to power four lanes, just be sure that your motor is set up for low power racing. There are really only a couple of times I've seen a stock toy car pull more than 1 amp and those are when the things are under full acceleration from a low speed or dead stop.

The things that burns these cars up are AC ripple and friction. AC is not good on a DC motor. Remember AC is alternating and DC is direct. A good power supply is very important. Batteries are best but they have some well known problems. A good power supply can almost equal a battery but more importantly for most, it requires very little maintenance. What makes a power supply good is how well it chokes AC out of the output, not how many volts or amps it produces.
 

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Hi

I wonder...you list moderators, this has been asked and answered a BUNCH. Perhaps an FAQ!

BTW, been using a 10amp/channel/lane supply for 25 years. Most antiques with crummy magnets have a higher current need than the modern motors, and thus, even on plastic revell track, need the AMPS.

Sigh.

The powersupply for your F1 in the 60s challenge will be this supply.

Fate
 

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Discussion Starter · #9 ·
Thank you all very much for your time and consideration. An FAQ would be great. If I learn enough maybe I will write it one day. Your tolerance of cornball questions like mine are appreciated and DO benefit the hobby.

Someone said no wall wart has that kind of juice to run 4 cars. I wonder what kind of beast Scalextric is releasing if it is a 24V unit (probably 24VA unit)? At some voltage the track can no longer be considered a toy because there is a specific regulation which governs voltage for "Toy transformers" by certain governments...certainly is the case for the US.

-Maltese
 
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