Lionel 90W transformer problem?

[slothead]

As my prior post reports, I got my dead strip to PC mouse connection working and set out to record more lap times to simulate a race. But, an intermittent power problem I've been having become so troublesome I had to stop racing and figure it out.

My road course is powered by a Lionel 90 Watt AC transformer that plugs into a Scalextric Powerbase that's wired to the copper tape on my track. I use Professor Motor controllers that also plug right into the Powerbase. I did it this way so the power supply and controllers are easily interchangeable with the same setup on my oval.

For the past few weeks the power has gone weak at times, meaning there are short term voltage drops. I don't have a voltmeter, but I'd guess the transformer is set at 12 - 14 volts, but at times it seemed to drop to around 6 - 8 volts (cars couldn't reach top speed on the back-stretch). I checked the wiring and swapped out controllers and still had the intermittent problem till I switched to a Scalextric wall wart transformer. So it must be the Lionel transformer. The 16 volt wall wart is too much power for my cars and track.

Anyone else had this sort of problem, and if so can it be fixed? I like this setup because I intend to try the AC method David Reinecke has on his track build pages.

Thanks for any help anyone can offer.

Slothead

[dreinecke]

Sounds like the transformer may be bad, however I'd recheck the wiring. How long is the track and are you running any taps? Is the copper tape on top of the Scalextric track or is your track routed? I can't remember.

[4424ever]

I originaly used the setup you describe, if it is a Scaley Sport base take it apart and check for burnt solder joints on the circuit board. Mine burnt to the point that I had to wire straight to the rails. Keep in mined that the Sport base is the rectifier that converts the wallwart A/C to D/C for the rails. The diodes on the board that covert the power are what usually burn up. Hope this helps!

[slothead]

Thanks for the comments guys.

I have a routed road course with a Scalextric Powerbase screwed to the bottom of the track with wires from it to the copper tape above. (The Powerbase for a 4 lane track has jumper wires to run under the near lanes and connect to the far lanes - these are what go to the copper tape.)

I tried rechecking the wiring and did find a place where the wire from the Lionel transformer was pinched. When I fixed that the power was fine for about 100 laps then started dropping again. Soon it got so cars where running about half speed most of the time with occasional bursts of full speed. So I gave up and am now learning to drive the track at 16 volts from the Scalextric wall wart which works fine. The problem must be in the Lionel transformer and I think these are hard to find these days. I bought this one online 10 years ago for about $50 and got my money's worth, though I would get it repaired if possible.

Lastly - could my 'too much power' problem be solved using a controller with variable sensitivity? Right now I'm only able to use up to half throttle most of the way around the track.

Slothead

[GTI]

Slothead, check out the AC2Car site. It has links to buy and or repair your Lionel transformer. I use the one as well except it is an AC track that is getting converted to AC2CAR soon.

Hope this helps and have fun!

[RichD]

The sensitivity adjustment on an electronic controller will not be much help if your track voltage is too high. The sensitivity adjustment only conrtolls the point at which the car starts to move when you pull the trigger, it lets you use all of the trigger travel. Some controllers have a choke feature, sometimes called traction control, that is more helpful when the voltage is too high. With most controllers that have a choke control the voltage will be reduced, except when you pull the trigger all the way. With some controllers the voltage is reduced all of the time, so your top speed might be lower. Some controllers have an extra switch so you can pick the scheme that you like best. The sensitivity and choke controls may interact with each other.
Is the output of the Lionel transformer DC? If it is AC the rectifiers in the powerbase will convert that to DC. The rectifiers have very limited current capacity so a transformer with more amps than a Scalextric wallwart is likely to burn them up sooner or later. It would be very unusual for a transformer to have an intermittent problem. 99% of the time they either work or they don't, so your wiring may be suspect. If you expect to go to AC2Car you will need an AC transformer, otherwise you might be better off in the long run getting a new power supply. A switching power supply that is regulated, has a variable output and is good for 10 amps can be found for about $70.

[slothead]

This is the Lionel 90W AC transformer I use on my routed road course. It connects to a Scalextric Powerbase connected to the copper tape for the track.


Th power problem did start about the same time I was debugging the dead strip used for lap timing. FYI - I didn't cut the tape for track power, I put 5" pieces of duct tape over them for insulation and then put 3" pieces of copper tape for the dead strip over the duct tape. I made the dead strip copper tape wider than the track power tape below the duct tape so the new screws through the track for the dead strip would miss the track power tape. Yes, even though I was careful here, this could be where there is a short. But, I'm reluctant to redo the once problematic dead strip since everything works fine when using the wall wart, which seems to rule out everything except the Lionel transformer.

Once again, thanks for any and all comments - HRW is a great resource.

Slothead

[dreinecke]

Slothead - actually, I'm not totally convinced after re-reading this that it is the transformer. I'd do a test of the transformer directly to the track and wire up the controllers. Get the Scalextric power base out of the way completely. I have a feeling something there is the culprit.

Is there any way you can rig that for a test?

Also, have you put a voltmeter on it to see if it is dropping?

[pgtr]

That is a very common postwar transformer. Its certainly not the biggest of that era but is PLENTY of amps. It is very old and may need servicing to make it dependable and safe. Likely culprits are the wiper or internal circuit breaker. Parts are readily available. I can look up part nos later if you determine its at fault. Since you don't own a meter there's probably not much debugging that can be done. Buy a cheap meter and check voltage at terminal next time it happens and go from there.

[RichD]

Since the transformer is AC you can't bypass the powerbase. It is very likely that the wiper inside of the transformer is dirty, causing an intermittent connection. That is a common problem even with expensive transformers that are variable. You should be able to open up the transformer and clean the it with contact cleaner, I doubt that any parts will need replacing.

[dreinecke]

Rich - I don't follow you...I don't use the powerbase and have the same transformer. Unless you mean since the controllers are plugged for it?

That's why I suggested getting the PB out and going straight to the track (you'd have to remove the controller plugs obviously).

The wiper comment is a good one though and could be causing an issue too.

[slothead]

Thanks for the ideas. I'll take the Lionel transformer apart tonight and clean it to see if that helps.

I would work around the powerbase but to do so I'd have to put diodes between the AC transformer and track, and cut the plugs off the controllers. This is all very doable, but then I couldn't use the controllers on the powerbase on the oval.

Also, someone might wonder why not test the transformer on the oval - well when I built the road course I stacked a bunch of wood and junk in front of the oval and can't get at it. I'll need a day of barn clean up time to do that. I have a great 24' x 29' open space in the loft for my tracks, but it's quite a mess right now.

Slothead

[RichD]

If your track uses the AC2Car system the power has to be AC, you would not need a powerbase with rectifiers. With that system there is a diode in series with each controller and those are wired in opposite directions. One controller varies the amplitude of the positive side of the AC sine wave and the other varies the negative side. The cars also have diodes wired in the opposite directions and their motors each see half wave rectified DC. The system allows two cars in the same lane to be controlled independently.

[pgtr]

[slothead]

I really appreciate all of the thoughtful comments. I took the Lionel transformer apart and didn't see any obvious issues. It has a wiper arm to vary the voltage and I cleaned the contact area. (With a thin piece of foam drenched with lighter fluid slid under the arm while moving it back and forth - YES it was unplugged at the time!) I let everything dry for over an hour then tried it again on the road course and after a few minutes the voltage drops returned.

I was able to clear out the space in front of the oval and tried the Lionel transformer there for about 15 minutes - no voltage drops. This wasn't an exhaustive test but does have me thinking the problem may be with the dead strip connected to a PC mouse. But I'm still confused why I don't have the same problem when using the Scalextric wall wart which is also AC. (Yes, a voltmeter would be very helpful about now, but the batteries leaked in mine and it's dead now, and our local Radio Shack closed a few months ago.)

I'm only using AC because that is what Scalextric uses, then rectifies it to DC in the powerbase. I'm guessing this setup was inherited from train sets when slot cars got started, and now they have a backward compatibility problem and can't change. I like using the powerbase as an easy way to connect controllers and a power supply, and being able to power both lanes by 1 or 2 transformers with the flick of a switch.

It'll be a few weeks before I have time to mess with this again. By then I'll get a voltmeter and do some proper debugging. I may end up using the Lionel transformer on the oval with the current setup and switch the road course over to a more typical setup using driver's stations and a variable DC power supply.

Slothead