USP - the ”humungous” capacitor and magic from Lenz

USP - the ”humungous” capacitor and magic from Lenz.

This sort of device and similar concepts, are not “new devices” but just revamped old ideas. With a bit of miniaturization and magic circuitry these will revolutionize the way we have to wire our layouts. Imagine not having to worry about powering our points (turnouts), not having a short circuit at the points (turnouts) causing the layout to shutdown, locos, even diesels with 12 wheel pickup, stopping due to a power interruption due to dirty track or some form of lack of power continuity etc.

The Power-1 USP (Uninterruptible Signal Processing) Module combined with a Lenz Gold Back EMF decoder, is not an excuse to neglect track cleaning and striving for the best power pick up arrangement on our locos, but there are times that locos do stop. These can be reduced 90% or even more by installing the Lenz combination. Smaller 0-6-0 or similar 4-6-0 steam engines etc that only have a short wheelbase with only 6 wheels picking up from stopping. Not everybody runs large diesels.

In O scale or larger, there are radio control systems that have a DCC decoder to control the motor and use on board rechargeable batteries, that only need charging after a “session” or can be charged by any suitable track. These systems do not require the track to “continually” supply power for the motor etc – the batteries do this. There are NO track cleaning issues or wiring problems, in fact no wiring at all, only at the “charging point”. CVP products make a system called AirWire 900.

I am hoping in the near future that we will be able to fit small rechargeable batteries instead of these 1 Farad super capacitors. But if the super capacitor was 3 to 5 times larger, then this would be a radical improvement. We will just have to see.

One day a similar system will fit into our HO locos, but for now we have to use what is available. There are always new gizmos designed for our layouts and the USP/Gold is one of these. They will not be everyone’s “cup of tea”, but for now, used in a “problem loco” to give uninterrupted operation not to mention the absolute quality of Back EMF motor control tossed in the deal.

I was so impressed by a demonstration of the Lenz USP, that I made my own cheap Stay Alive to my Soundtraxx DSD-100LC sound decoders to reduce the annoying “sound resets” that are common with this decoder, using a 330 uF electrolytic capacitor, that room can be found in most locos for just the sound section, to a 4,700 uF capacitor for a sound and motor control. I have used it an NCE D13SR and a TCS T1 for motor control.

After posting a message on my train groups and getting “heckled” about the “new device”, I just had to get my USP and already being a convert to Back EMF decoders, I had a Lenz Gold on hand. Today it came and I just had to do my own tests below. I hope you can get the full picture. If only I could upload a small video, but that probably would kill my web space then, and I don’t know how to do it anyway, so stills will have to do.

That’s it and compared to my Stay Alive 4,700 uF capacitor, it may be tough to get it into a 0-6-0 tank steam engine.

I removed the heat shrink and boy there is a lot crammed in there. Along with some magic electronics on one side there is a “humongous” 1 Farad 2.7 volt Super Capacitor. Shown as a comparison is a my Jaycar Electronics hobby electronics supply store 1.0 Farad 5.5 volt Super capacitor that would not even supply a 10 ma LED for a couple of seconds. I guess this unit is intended for computer memory backup, replacing a battery etc and only designed for micro amps current drain not 10 or 200 mAs that we need.

That’s obviously what is so special and makes the USP quite a bit more expensive than my super capacitor, but there is more – much more. DCC control, without “two rail contact”, yeh you don’t believe this. See below.

Shown above are the two Golds. The normal larger JST decoder (lower) and the Gold Mini (above) for comparisons. The USP is connected to the normal Gold JST. The solder pads for both decoders are the same “small” size.

The USP’s 3 (blue, pink and brown) wires are connected to the 3 solder tabs on the Lenz Gold and installed the Gold’s NMRA 8 pin plug into one of my Trainorama 44s. The soldering has to be done with a small iron and a steady hand. There is a Gold Superpack combination USP and Gold decoder available from Tony’s at US$75.95 already soldered together. That will save some hassles.

A “better” type of decoder with much less feature costs US$ 25 – 30, so this total solution is pretty good value in my opinion.

Now for the “real tests”. I was amazed at the results. I am using a 12 wheel pick up medium sized diesel and using my NCE DCC system on 128 speed steps, with a small amount of inertia (momentum) in the loco.

My test track on my workbench with three pieces of tape applied to BOTH tracks on a turnout and a piece of tape 12 inches long on either side 5.5 inches and 7.5 inches from the turnout. Not much metal to get that DCC signal for power AND control. The train won’t get from one end to the other, or will it?

Starting at one end at 30 S/S (128), the loco proceeds along the track without stopping and the super capacitor gets charged up in between taped areas. That is 13 inches in 37 inches that there is “metal”. Far less than 50% of the time, that the loco “gets” power and control.

For the 12 inch tape with the test loco having a 6 inch wheel base, that leaves a total of 6 inches of tape that NO wheels are in contact with any track for 6 inches. At a speed of 30 S/S (128), that takes the loco to move over this 6 inches about 2.5 seconds of total loco motor power from the USP. The loco is drawing about 100 mAs during this slow running.

If the loco has its headlight selected on, the Gold turns this OFF slowly to further reduce power consumption while in the “dead” section. As soon as the loco receives normal power, the headlight comes back on.

This example except for the turnout is exaggerated to prove a point. For the turnout, if the “point rails” and the “frog” were not powered, this would be less length of no power.

An 8 inch Peco medium turnout completely covered by tape. I did this deliberately to take the “electrics” out of the turnout and the rail is only used to guide the loco on its way. This is not just a “dead frog” it is a dead turnout”. Imagine how easy it is going to be wiring the layout. No micro switches or Tortoise/Peco point motor auxiliary contacts/switches. Soooooo easy and no shorts.

This USP/Gold combination will now allow me to make all of my Peco Electrofrogs into ‘Dead Frogs” by cutting a slot with the Dremel either side of the frog, and go the way of one of my modeller friends here in Australia, Gerry Hopkins who exclusively uses “Dead Frogs” on his turnouts on his trouble free Great Northern Downunder layout . He also connects the point rail to the adjacent stock rail. This makes the turnout totally DCC friendly. Dead Frogs can only be used with locos with all wheel pickup or a steam loco with both power pickups on the engine and the tender. My Austrains 4-6-0 36s could never cross a “Dead Frog”, as it only has the 6 drivers picking up power, but now it could with the USP/Gold.

While reversing the loco at 30 speed steps from 128 (pretty slow), I hit the direction button on my Procab at this above position. NO wheels in contact with ANY rail. The loco receives the COMMAND through the tape and reverses out of the tape.

Another test, at speed step 1, the loco wholly on the tape. I set to 0. Waited a few seconds and selected reverse. Selected speed step 1, and the loc slowly drives off.

The above tests show that the decoder does receives commands through the tape, without getting power. How the Gold and the USP do this, I have my theories and others have explained. I will add these later.

Using the Gold Mini and the USP.

Enough of the test setup, now for some practical uses for the USP, which it is designed for reducing stoppages from power interruptions that could be caused by dirty track, poor pickup designs and points (turnouts) design (frog gap and insulated plastic frogs) . I connected the Mini into one of my smaller 30 class steam tank locos, for the test it was located in a wagon behind the loco. The size of these locos rules out installing a Gold JST and a USP, so the Mini is essential.

The Tests:

The Gold Mini/USP combination was fitted to 2 locos, a 12 wheel diesel and a loco that has only 6 wheel pickup similar to a 0-6-0. I tried two Minis and got the same results. With S/S 20 out of 128.

12 wheel diesel, tape on 2 tracks = Does NOT work at all, loco stops as soon as all the wheels are on the tape.

12 wheel diesel, 10 inches of tape on 1 track = Loco DOES travel over the tape. Time without power, about 4 seconds.

0-6-0 steam loco 10 inches of tape on 2 tracks = Loco STOPS as soon as all wheels are on the tape. Confirmed by ammeter on the NCE Power Cab

0-6-0 steam loco 10 inches of tape on 1 track = Loco STOPS as soon as all wheels are on the tape but with only the tape on the RIGHT hand rail works well with the tape on the LEFT rail. Something strange with this loco.

Used an Austrains 36 that has only the 6 driving wheels picking up, similar to any 0-6-0 loco. This loco works with either track “taped”.

So it seems you might have different results that I have experienced with my two “0-6-0s”. I will see if I can track down the problem with the 30 class tank engine shown in the above photo. The only difference between the two locos is the type of “pickup” used.

Austrains 36 has a split chassis and uses “bushes” similar to all locos.

The 30 class has “bushes” that are used for pickup (chassis) on the left hand side BUT on the right hand side, the tyres are insulated and use wipers on the backs of the wheels for current pickup. The wipers seem to be the “problem” even though the loco works well with DCC under normal conditions.

When connecting power to the decoder’s red and black wires directly (bypassing the track pickup “wipers”), when removing one lead at a time, the motor (wheels) kept turning for a couple of seconds. No problem with the decoder installation or the loco. This leaves the wheels, wipers and track.

Wipers etc, is the only difference between the two locos. The Gold Mini must “feel” this as a difference and is not happily “coupled” to the track when using this side only. I will investigate further soon.

Observing my Power Cab ammeter reading while operating the Gold JST/USP combo, the reading is fluctuating around 10 – 30 mAs at S/S 20 (128) while the loco is moving. Obviously when it goes over the “taped frog” it drops to “0” mAs. As soon as some wheels contact the track again, the ammeter goes to about 300 – 400 mAs and progressively drops to 10 – 30 mAs in about 5 seconds. This is the USP charging up again. Also I can see that the USP only gets charged when the loco motor is supplied with voltage. This means when the layout is turned on, the USP is NOT being charged.

My initial excitement about the USP was severely dented, but further investigation about the 30 class as explained above has me back on track with the Gold Mini and USP. So you may have similar problems, depending on the type of pickup.

The above photo shows my loco mechanism with the wipers on one side. This loco only works ONE way. The USP is only working when the power interruption (gap) is on the track that the wheels with the wipers are contacting.

It seems that the when the wipers are the only source of power, the USP does not work.

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