[cbwho]

Using diode shoes and Tomy/AW track, I plan to run an AC2Car HO set up. What's a good 16v AC power supply to use? I have some older Tomy power packs, so I'll splice in the cord to whatever I buy.

I doubt it's a good idea to use my Difalco running thru a diode (or will it work fine?) But I have an old Aurora adjustable rheostat controller so I'll give that a try.

I'll simply use AFX style track with an odd number of cross over lanes. A driver can lane change by driving too fast (but not too fast) into a corner with the fence to help guide. Eventually I'll modify a cross over with lane changers.

 

[cbwho]

I'll inspect my AW and Tomy terminal tracks for capacitors and remove them as I think they are a bad idea and I doubt that'll work for AC. (I don't think they are there as I've only seen them on Racemasters.)

Faller AMS selenium shoes withstand a max reverse voltage around 25 volts. I will be using 16v volts AC. Half-wave 16v AC is equivalent to 12v which is suitable for Faller AMS cars. I plan on converting some AutoWorld ThunderJets as well.

 

[Glock24]

Will this let you control 2 cars on the same lane with different controllers or what is the purpose?

 

[finbar]

Hello,
Nice idea! Yes, 16VAC is good for Faller cars. The power of each car per lane is is halfed with AC2Car setup. This power reduction calculates to a voltage of around 11.3 VDC equivalent. There is another voltage drop at the pick-up shoe diode as well as the controller diode, together around 1.0 volts. So there are 10.3 VDC left. T-Jets may need a little more power than Faller cars do, however I would check if they are still fast enough to race them, with 10.3 VDC supplied.
Regards
finbar

 

[cbwho]

I noticed the Lionel AC transformer goes to 18v so that would be better.

I usually run my cars 12v DC

 

[cbwho]

Will this let you control 2 cars on the same lane with different controllers or what is the purpose?

With a 2 lane track with a odd number of cross overs, both cars will be controlled separately and can go anywhere they wish. With this setup, each car will always go forward so they can even race backwards. I believe stock AW* cars will work and will experiment with those.
(*Of course Faller cars will work as well. I now have a few of those.)

 

[RichD]

Difalco controllers are transistorized and may be damaged if they are hooked up to AC. I looked at the AC2Car site and that said that electronic controllers can be used, but Professor Motor controllers were mentioned specifically. The older PM diode controllers should work, but maybe not the newer transistorized ones. Trying a Difalco controller would be risky in my opinion.
I expect that the Faller cars were intended to be run at 12 volts. Aurora and Johnny Lightning/Auto World cars are rather slow at 12 volts.
If you wanted to be able to increase the AC voltage you could replace the Lionel transformer with an autotransformer. Those are sometimes called powerstats. With an autotransformer you can adjust the AC output from zero to full line voltage. If you were to use one of those you would want to put a stop on the knob to keep from turning the voltage up too high. New powerstats are expensive, but you might be able to find one on eBay. I have one that I fished out of the dumpster at work, all it needed was to have the contacts cleaned. I used that to make a variable DC power supply by adding a bridge rectifier and some filter capacitors.

 

[finbar]

Hello,
I want to point out an alternative method, which you may think about, if you are a little experienced in electronics.
There are electronic devices available, so called H-bridges, which are able to switch a motor on/off. Beside that, H-bridges can switch the motor on/off in reverse polarity without rewiring it. When switching forward/backward in a fast sequence, the device produces a kind of AC, which shows a rectangular form. With the diode pick-up shoes, it is possible to operate one motor with the normal polarity and the other motor with the reverse polarity simultaneously. It needs a little control logic, but in the end, you just have to supply a DC voltage to the device. And with an adjustable DC power supply you are able to select the voltage according to our needs. The H-bridge device I am using is the L293D which actual includes two H-bridges of the described kind, so a single L293D is able to operate 4 cars on two lanes independent. For control logic I use an Arduino.
Regards
finbar

 

[cbwho]

I'm looking to do something simple

New message from: difalcodesign
Right now I am not sure but I think they can be. Below is the website for AC2 cars which I guess you have visited? They mention a Professor motor controller which is similar to mine in design so if theirs will work so will mine. I will have to read more about it. They did not have any real contact info on the website. Have you ever contacted them? jim

» Racing Action on Jimmy’s Northline Raceway

 

[Wicker Bill]

I managed to find the recommended Lionel transformer at a local train show. It’s now running Lionel trains at my friend’s house.
I found the AC2Car folks very responsive when I did my track, but that was years ago.
I used basic Parma controllers and would recommend something similar (resistor type).

 

[cbwho]

Today at my brother's place, we had some time to set up a quick AC2Car setup. I had some selenium shoes arrive. He has a Lionel AC 18V transformer which we don't know how well it works. Anyhow set everything up on some Tomy track but the cars were very slow. We measured the voltage on the track and it read 15v AC. Was the amps too anemic?

 

[finbar]

Hello cb,
Please remember, modern voltmeters calculate the effective value of an AC. Therefore, they expect a perfect sinus wave AC. If you measure a rectified AC, they may show a wrong value.
However, sometimes the selenium diodes are corroded and there may be a voltage drop, but from the pictures they look good. How many cars did you run? Will they be faster when you half the load, one car instead of two? This would indicate poor amps from transformer to me. If one car is similar slow than two cars, I would probably increase voltage.
Regards
finbar

 

[cbwho]

Ok, that gives me some hope! The bought-used Lionel transformer might be bad as the bought-used train he has with it, the locomotive doesn't run very well. We thought it was the locomotive but maybe it's the transformer.

 

[cbwho]

I have a couple Aurora vibrator cars, so this transformer could have dual purpose.

It's 22VAC so we'll below the limit for selenium:
"Each cell can withstand a reverse voltage around 25 volts"

 

[cbwho]

For our test we used 2 vehicles, a Aurora TJet with the sandwiched selenium shoe and a Faller Formel car with a plastic encased selenium shoe. The tjet barely crawled. The Faller went but wasn't racing fun as could not go fast enough to deslot.

It was mentioned in a previous post that 16V AC voltage is worth about 0.7 as DC (unsmoothed). But isn't that for full wave unrectified?

Looking at my excel analysis (I didn't want to try to remember trigonometry calculus integration), the perceived DC voltage from half-wave AC is a mere 5V from 16V.

So to get this to work with performance, I'd have to get some hotter armatures perhaps 6 ohm ones for some Dash TJets?

 

[HDK]

16V AC voltage i

Isn't AC voltage usually given as the RMS voltage? So the peak voltage would be higher (peak =16x1.414).

16V AC RMS should be roughly equivalent to 16V DC in terms of applied voltage. And it seems like 1/2 wave rectification would give you 1/2 of that? So 8V? Ignoring the diode losses...

 

[RichD]

I have built a number of power supplies. The AC output of a transformer would be an RMS value. If you use a full wave rectifier and a filter capacitor the DC output reading will be higher than the AC RMS value. I have forgotten how much that difference was.

 

[finbar]

From my point of view, the nominal output voltage of a transformer is well known as it is printed on its label or housing. It is the AC RMS value and is defined to provide an equivalent energy to a resistor load than a DC voltage of the same value. The nominal output voltage is guaranteed for a given maximum output power, the VA rating which the transformer is specified for. In case there is no load to the transformer, the no load voltage will rise above the indicated RMS value,.

Peak voltage is 1.414 times AC RMS voltage. A full wave rectifier with a filter capacitor will charge up to the peak voltage, so 1.414 times AC RMS voltage.

I still believe half-wave operation shares the power between both cars. In an earlier post, I calculated 11.3 Volts for each car based on a 16 volt supply. Vice versa, if you like to run the cars at a speed that corresponds to non half-wave operation, I believe you will have to supply double power. When power P = U*I or P = U²/R and R is assumed to be constant then doube power 2P is achieved by 1.414*U. In other words you will have to increase voltage from 16.0 volts to 22.6 volts. So I suspect the vibrator transformer will be worth a try.

Please tell me where I am wrong.
Regards
finbar

 

[cbwho]

Thank you @finbar and others. I have tons to learn. I think the circuit class I had in 1994 was DC and I think AC wasn't covered?

I'll study this:

https://www.electrical4u.com/rms-or-root-mean-square-value-of-ac-signal/

Interestingly, I work a lot with statistics, so RMS I know well. 😸

 

[Weltmeister1969]

I run AC on a 3 lane 1/32 scale wood track using a 60s era Lionel LW 125 watt TrainMaster transformer with no issues. I only have diodes in the controllers, so not full AC2Car. It has a built-in circuit breaker and a button that controls track direction, which I’ve wondered if could be made functional for a slot car setup. More than enough power for 1/32 ~2Amp motors. Glowing dial a plus as well. Nice to see interest in heretical AC.