# Power supplies



## BigGlittleo (Jan 31, 2015)

Got an old not working laptop charger laying around, chances are that the plug is bad. I cut the plug off of my charger and soldered the plug off my wall wart to it. I ended up getting18.5 volts instead of 13.5 volts and 3.5 amps instead of.8 amps. Thats over 4 times the amperage and what a difference!

Most of the time the wires break at the plug on a laptop charger, making it useless unless you replace the plug. I cut the plug off and checked the voltage, all good. I slipped some shrink tube over the wires first then unraveled the coax outer wire and twisted it together, soldered one of the wires from my track connector and center wire to the other. I heated up the shrink tube over the soldered connections and quadrupled my amperage!


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## Boosted-Z71 (Nov 26, 2007)

I have used the laptop power supplies for a long time, they work great and If you have a Goodwill store near you, they generally have a good supply, any where from 5 volts (great break in power supply) up to 32 volts, and the best news is most of the time they are $1.99 or if you purchase them in the stores bargain hours they will be 1/2 price.

Boosted


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## tasman (Feb 17, 2007)

You can buy new universal laptop supplies with variable voltage for around $30. I have one that I haven't hooked up yet to replace a standard laptop power supply. It can do several different voltages from below 12v to I think 24v.


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## BigGlittleo (Jan 31, 2015)

The amperage increase is what I was really looking for. Some of my rewinds won't run on a wall wart and I didn't want to spend $100-$200 on a high amp power supply. Gordon


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## Boosted-Z71 (Nov 26, 2007)

BigG, I have 2-24 volt 5 amp laptop power supplies on my Dyno, so you can easily get 5 amps per lane out the right laptop supply, Like I said I get all mine from the local Goodwill store, $1.99 ea.

That should make all the power you need for any rewind

Boosted


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## BigGlittleo (Jan 31, 2015)

*Power Supply*

Have to check out my local goodwill. I saw some universal chargers online for about $15. At $2 I can hook one to each lane.


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## JamesRoberts (Mar 26, 2015)

I found a pretty decent power supply at mpja.com They have a 0-30VDC 0-3A variable power supply for $50. My neighbor bought an Astron one, and spent about $3-$400 for it. Yikes!


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## Boosted-Z71 (Nov 26, 2007)

The most important thing in a power supply is how much AC ripple comes through to the DC side, while it can be filtered out by adding caps quality power supplies have provisions already built in to take care of this. The power supplies with a ton of AC bleeding thru will cause your cars to run hotter. Still easy to measure AC ripple and filter out, always good to know of places to get fair priced power supplies. 

Boosted


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## northwest slot (Dec 1, 2009)

A 3 amp power supply will have trouble keeping up on a four lane track. I went the Astron route and found a good one for $160. They are made in the USA, so I am happy paying a little more for that. I think Ham Radio Outlet may have them.


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## Ovalhead (Nov 20, 2010)

*MASTECH * " nuff said ! "​ :dude:


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## Black Oxxpurple (Jul 3, 2011)

Ovalhead said:


> *MASTECH * " nuff said ! "​ :dude:


Agreed


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## beast1624 (Mar 28, 2009)

Black Oxxpurple said:


> Agreed


That's mine too. Been working great for 5 years


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## Dyno Dom (May 26, 2007)

Any specific model suggestions for adjustable voltage and 20 to 30 amps for either Astron or Mastech power supplies??


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## cwbam (Feb 8, 2010)

price check with these guys
http://www.omnitronelectronics.net/phpstore/html/Power-Supplies-Assembled-95-1.html

I picked up a Kepco from ebay 30v 30amp
running good on a 6 lane Buck Scorpion and have recently ran some 
3 ohm races 

http://www.ebay.com/sch/i.html?_odk...RC3.A0.H0.Xkepco.TRS1&_nkw=kepco&_sacat=58288

I think it maybe a rectifier / plater power supply


professor motor has a 20v I forgot its amperage?


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## Ogre (Jan 31, 2007)

http://www.professormotor.com/product-p/pmtr1400.htm

It says out of stock, but it will be back.


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## Rich Dumas (Sep 3, 2008)

I have a couple of these Mastech power supplies.
http://mastechpowersupply.com/dc-po...otors-and-aviation-applications/prod_141.html


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## beast1624 (Mar 28, 2009)

On Mastech's site they actually have a section for Slot Car Power Supplies:

http://www.mastechpowersupply.com/slot-car-power-supplies.html

This is the site I bought mine from . I believe if you get a 30V 10A or 20A adjustable that should work for HO just fine.

I bought this triple output PS for my track a few years back. Have not needed the extra outputs. Original thinking was one output for 2 lanes and the other for the other 2 lanes so I could have one voltage for adults and one for kids. Worked ok until it was time to install the timing system. I wound up the two variables together parallel to get 30V 20A and have never installed accessories to use the fixed output. It was really overkill. If I had it to do again I would pick one of the ones like Rich has and saved some $$.

http://www.mastechpowersupply.com/m...-supply-30v-10a-hy3010e-3-triple-outputs.html


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## Black Oxxpurple (Jul 3, 2011)

Mine is 30V 10 amps and plenty of power. I looked at the dual out power supply and it would be nice if I had the drag strip set up. That has not happened since I bought the 3010 Mastech. Well worth the money.

If I were to buy one today, just to have the extra amps for bigger racing arms, I would look real hard at this unit.

http://mastechpowersupply.com/dc-po...otors-and-aviation-applications/prod_141.html

Rob


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## Dyno Dom (May 26, 2007)

I have an MG supply, adjustable 0-20 volt, 10 amp for 6 lanes approx. 76 ft. road course with no issues. 
I run G-Jets at 12-14 volts, most inlines at 18.5 and pancakes at 19 volts so
really no need for higher voltage but would like to increase the amps. 
The Mastech 20 amp looks good but so does the 30amp for $50 more.
Any concerns with differences between linear and switching power supplies? 
My current supply has a power cord for 110 outlet and two front terminals of
red & black for wires to track. Are the Mastech units similar??


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## aurora fan (Jan 18, 1999)

I've got 4 "wall warts plugged into a powerstrip. I used to race at Neils Wheels in Plano and another Pro place in Hermosa Beach and my cars didn't go faster. I'm saying my 4 lane Tomy works really good I think or am I completely missing the point on these Power supply options and maybe I should look into it?

Edit to add I see this topic from time to time but never wanted to ask because I didn't want to seem uninformed but I've been racing as long or longer than any of you so don't be all harsh or snarky with an answer if you please. I'm just a regular guy so I figure others might like to know too


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## Rich Dumas (Sep 3, 2008)

I have never seen any tests comparing switching and linear power supplies. A good linear power supply should have a cleaner output and be faster to respond to load changes, but I am not certain if the differences make any practical difference. Originally my track was powered by a pair of Lambda 8.6 amp laboratory grade linear power supplies. I got those as surplus from work and after maybe 30 years one of them started to have problems with the display. My track was already set up for two power supplies and was wired so that I could run high end cars that pull 10 amps at start up. I was looking for at least a 20 amp linear supply, but I couldn't find one. I ended up with a pair of 20 amp Mastech switching power supplies that were on sale. With the two power supplies I can run two lanes with pancake cars at 18.5 volts and the other two lanes with G-Jets at 12 volts at the same time.
When I still had the Lambda supplies I did do a little testing to see how good the regulation was. I set the power supply at 18.50 volts, then loaded it with a light bulb to get a 0.63 amp draw, the output dropped to 18.37 volts. With another light bulb added the load was 0.95 amps and the voltage dropped to 18.30. Some day I may repeat the testing with a Mastech power supply.
I have also done some testing to see how much power a car actually uses on the track. Slot cars use a great deal of power when they first start up, for a regular inline magnet car with a 6 ohm armature that is about 3 amps. Once the car starts to move and is still accelerating it will draw about 0.5 amps and that settles down to 0.25 amps when the car reaches top speed.
Since the car only draws a lot of amps when it starts up sizing your power supply based on that is probably a waste of money unless you are drag racing.
I usually recommend a minimum of 1 amp per lane for regular HO cars. Having a regulated power supply is important if one power supply will run several lanes. Set type power supplies are not regulated and the voltage will really plunge when you apply a load. One supply that I tested was 19.0 volts with no load and 14.2 volts with a 0.55 amp load. A single car will be pulling that many amps much of the time, so I consider that voltage drop to be significant. With a separate wallwart per lane you will eliminate the problem of power surges when one car comes off, but the power will still be soft. The cars will not have quite as much snap with an unregulated power supply because the voltage will drop when you get on it. The positive side to that is that some cars will be easier to drive.


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## JazzyJerome (Feb 14, 2012)

aurora fan said:


> I've got 4 "wall warts plugged into a powerstrip. I used to race at Neils Wheels in Plano and another Pro place in Hermosa Beach and my cars didn't go faster. I'm saying my 4 lane Tomy works really good I think or am I completely missing the point on these Power supply options and maybe I should look into it?
> 
> Edit to add I see this topic from time to time but never wanted to ask because I didn't want to seem uninformed but I've been racing as long or longer than any of you so don't be all harsh or snarky with an answer if you please. I'm just a regular guy so I figure others might like to know too


That's what I have no complaints here I am wondering what improvements are there to gain with one of these power supplies?


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## Rich Dumas (Sep 3, 2008)

It is nice to know how much power the cars you run are using if you want to buy an aftermarket power supply. I tend to look at things as a racer and I want the track voltage to be constant no matter what cars I run. For the more casual racer one set type power supply per lane will be fine if you are only running cars with 6 ohm or higher armatures. Cars with more powerful motors or stronger magnets will not perform at their best when powered by a set type supply.
A greater advantage to using an aftermarket supply is that they are usually adjustable. If kids are running you can drop the voltage. G-Jets and gravity cars are usually run at 12 volts while most other HO cars are run at 18-20 volts and drag racers like 24 volts.


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## JazzyJerome (Feb 14, 2012)

Rich Dumas said:


> It is nice to know how much power the cars you run are using if you want to buy an aftermarket power supply. I tend to look at things as a racer and I want the track voltage to be constant no matter what cars I run. For the more casual racer one set type power supply per lane will be fine if you are only running cars with 6 ohm or higher armatures. Cars with more powerful motors or stronger magnets will not perform at their best when powered by a set type supply.
> A greater advantage to using an aftermarket supply is that they are usually adjustable. If kids are running you can drop the voltage. G-Jets and gravity cars are usually run at 12 volts while most other HO cars are run at 18-20 volts and drag racers like 24 volts.


All of my cars are stock that's probably why I don't have any issues.


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## leonus (Dec 17, 2013)

So why buy one that costs $250 when you can get one on ebay for $50??


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## cwbam (Feb 8, 2010)

another advantage of a single power supply is for track timing
with a single power supply your power supply can be controlled
by relay which is controlled by your timing system

I've had some luck with Kepco brand old school (rectifier?)


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## Rich Dumas (Sep 3, 2008)

If you are using a computer to manage your races or just have a relay or switch to turn the track power on or off it is best to leave the power supply on and put the switch or relay between the power supply and the track.


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## Hittman101 (Oct 21, 2009)

Would something like this work..http://www.ebay.com/itm/30V-5A-Prec...451?pt=LH_DefaultDomain_0&hash=item58b1aaaffb


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## alpink (Aug 22, 2010)

find the one with 10 amps. only a little more $

http://www.ebay.com/itm/30V-10A-10A...241?pt=LH_DefaultDomain_0&hash=item339cf10111

http://www.ebay.com/itm/WEP-30V-10A...532?pt=LH_DefaultDomain_0&hash=item5b0e495b94

http://www.ebay.com/itm/30V-10A-10A...612?pt=LH_DefaultDomain_0&hash=item4d12fb6b04


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## Hittman101 (Oct 21, 2009)

Thanks Al I think I will stick with finding 2 more parma controllers then the power supply..


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## vickers83 (Mar 8, 2010)

I`ve got the 10 amp 30 volt variable power supply like AP showed. It works great, I power my O-Gauge road course & my 4 lane Tyco oval with it. We can run all six lanes at once with no problems! Best $70.00 I ever spent on my tracks! :thumbsup:


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## leonus (Dec 17, 2013)

With a single wal wart you get surges and dips operating two lanes...

With one of these thats not an issue so you can run a single one??


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## vickers83 (Mar 8, 2010)

leonus said:


> With a single wal wart you get surges and dips operating two lanes...
> 
> With one of these thats not an issue so you can run a single one??


All 6 lanes running, One or two cars fall off & no voltage surge. Everybodys happy!


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## leonus (Dec 17, 2013)

For a 2 lane track thats pretty long (around 50 feet ) you would need 10 amps?

Dont need more than 20 volts. Run 14 volts now and plenty fast. Have two wal warts with power at two places. Its just really hard to get equal output from the warts and id like to be able to adjust power up and down. Especially down for kids and visitors.


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## vickers83 (Mar 8, 2010)

leonus said:


> For a 2 lane track thats pretty long (around 50 feet ) you would need 10 amps?
> 
> Dont need more than 20 volts. Run 14 volts now and plenty fast. Have two wal warts with power at two places. Its just really hard to get equal output from the warts and id like to be able to adjust power up and down. Especially down for kids and visitors.


The power supply is variable, I run mine @18.5 volts for inline or pancakes. Amps are drawn by the car, not forced into them. My pancakes draw at the most 8/10`s of an amp and inlines not quite an amp on start up. I don`t run anything with HD magnets in them. Just stock Tyco`s, Lifelike M cars, Tjet, Old AFX or magnatraction. The guys who need all the amps are running cars with neo magnets w/hot wound arms most of the time. Just my 2cents worth.....Gary :thumbsup:


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## alpink (Aug 22, 2010)

Gary, good point and well worth considering.
agreed, most cars are not going to need a great amount of amperage and this is why some folks use laptop chargers to power their track.
I have also found that around 18 volts is very popular among many home racers.
I drag race and I prefer 24 volts. I do, sometimes, run some very powerful cars and 10 amps is required. but, you know what? that isn't very often and I could probably get away without uisng that power supply.
my buddy, Hank, has my old 1/64 1/4 mile drag strip and that uses automotive batteries for a total of 24 volts and well over 900 Cold Cranking Amps. 
the cars love that kind of DC and it is quite clean. 
I always enjoy folks ideas about what to use for power and the various reasons why.


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## Black Oxxpurple (Jul 3, 2011)

I also have a pair of hamsters turning wheels inside my box for when the power goes out.


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## leonus (Dec 17, 2013)

Thanks for the info. Didnt mean to hijack anyones thread.


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## Rich Dumas (Sep 3, 2008)

The length of the track is not a factor when you are selecting a power supply, the cars use power, not the track. You can get a voltage drop because of resistance in the wiring and track rails. Bad track joints are usually the cause of larger voltage drops. The longer the track is the more likely it will be that there is a drop on the far side of the track. People often add a few sets of jumpers to minimize problems with voltage drops.


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## Crimnick (May 28, 2006)

One of the best investments I ever made was a used trackmate 30amp regulated 0-30 volt power supply.

We race at 18volts but I run it at 12 volts for the kids.


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## Rich Dumas (Sep 3, 2008)

If you use a monster power supply you you should have a separate fuse or circuit breaker for each lane. The biggest dangers are to get a short across the rails or to hook up a controller wrong. Do not count on the fuse in the power supply or any protective circuits that it might have to protect your wiring, track, controllers or cars. If the power supply has an amp control leave that turned all the way up.


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## leonus (Dec 17, 2013)

So how would one wire fuses?

On the hot side of the lines going to the track?


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## cwbam (Feb 8, 2010)

*Wiring*

Fuse Block

power supplies
Track Wiring


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## leonus (Dec 17, 2013)

Wow
Thats a bit over my head but thanks.

If im using a max 30 volt 5 amp regulated supply for a two lane track that runs stock arm AFX cars and a few AWs, 

Do I really need fuses and if so couldnt i just hook a 5 amp fuse on the positive side of the power feed?

Sorry but not an electrician..


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## Crimnick (May 28, 2006)

You can wire a fuse holder in line that will protect both lanes.....you can get them at most autoparts stores..


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## Rich Dumas (Sep 3, 2008)

A separate fuse for each lane is best. I would put that between the power supply and the white controller connection, that is the one that goes to the resistor in a controller. The lower the amp value of the fuse the more protection you will get, but if you go too low you will be burning fuses during normal operation. A fuse can pass more than it's rated amperage for a short period before it blows. That is a good thing because slot car motors pull a lot of amps when the first start up. A car with a 16 ohm armature will try to pull 1.5 amps for an instant. If you had four cars on the track at the start of a race they would briefly need 6 amps. If you just had a single 6 amp fuse you would never blow that if everything was OK, but if someone hooked up wrong of if the track got shorted 6 amps if a fair amount of juice, enough to cook a controller in seconds.
I know someone that burned up his track wiring and a very nice custom track without fuses was damaged when someone hooked up wrong.
My own track now has circuit breakers.


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