I have a new ZW with the 180W bricks. It works fine if I use either DCS or TMCC to control the voltage to the tracks for my conventional trains. However, it does not work very well if I use the throttles to control the track voltage because very small changes in throttle position produces very large changes in train speed. The problem is that the ZW does not begin to ramp up voltage until about throttle position 12-14. Therefore, the throttle handle is useless between positions 0-12.
I am thinking about getting a post-war ZW combined with circuit breakers to control my conventional engines. What throttle position (0-20) provides sufficient voltage (5 volts) to start a train moving on the postwar ZW?
I have 2 post war ZW’s and they both move the 1666’s that I run at about 5-7 volts. They seem as if the handle positions are pretty sensitive all the way through their range. I did put new rollers on all four handles on both units however, not sure if that made a big difference, but I’m guessing it might. Jake
My understanding, along with experience and observation of the internal mechanism mechanism of the postwar ZW’s, is that the secondary coil is “tapped” by the rollers at somewhere around 6 volts minimum – maybe as high as 8 volts. That is, when throttling back, the wipers roll right off the coil at no less than 6 volts and park on an insulating piece. Therefore there is no output at all between zero and 6 volts.
Thus, when throttling up, the output goes from zero to 6 volts (maybe even as much as 8 depending on a given example) which tends to jump-start some modern locomotives with light loads. It is not that much of a problem with pre- or postwar locos, which needed higher voltages than many of the modern ones do.
That said, the old ZW’s seem to produce a gradual and relatively linear output between 6 and 20 volts which gives reasonable throttle control, but nothing like the “two hundred or more” steps I see advertised with some modern control systems.
Some folks prefer the old 1033 transformers for “sensitive” locomotives becaise it will throttle smoothly between zero and 11 volts – if you use the correct taps; but to get the full 16 volts out of a 1033 you lose the low speed control because the range shifts to about 6 to 16.
Most everyone laughed (until recently, at least) but in fact the lately revised CW-80 will give smooth throttle control from zero to 16 or even 18 volts, depending on whether you use lionelsoni’s voltage conversion chart, but the total power available is comparable to a 1033 rather than an old ZW. (You can “over-drive” a 1033 a bit, particularly if the thermal circuit breaker is stuck, but the “fold-back circuit” in the CW-80 will not permit such abuse.) On the other hand, the CW-80 has a built-in lag between the movement of the throttle handle and the change in voltage at the track. Some folks find this annoying and not conducive to fine thro
I have a post war ZW and like the output levels very much. Works great with everything that I have.
From every thing that I have read about the new ZW I would not give you a $5.00 bill for a truck load of new ZW’s. Also hate the fact that you have to add separate power units to a transformer. Have tried a new ZW at a train show here in south Florida and the new ZW is not for me, totally differant than the PW model.
Chuck, are you an audiophile? as you mentioned about calibrating a ZW.
Probably not. New ZW’s resemblance to the old one is literally only skin deep.
The new unit is an electronic controller. If you really, really liked the original, you will probably not like the new one. Of course the new one can control 760 watts of out put power vrs 180. It also can start at 0 volts instead of 7. The controls are deliberately non-linear in time response (aka decreases are at approximately twice the speed of increases). All of this (and more) is in the owners manual. The unit is different, not necessarily better or worse, just different.
The reason I mentioned audiophile is because I had an old Pioneer cassette deck that required you to calibrate the Dolby noise reduction unit to record on a cassette tape.
The new ZW’s are out of my price range too!
I will keep my pw ZW & Z type transformers until they can no longer be repaired. Have the proper current protection for newer trains with the old ZW.
According to the service manual, the original ZW starts at 8 volts, which is a little high. The manual says that “The three fixed secondary windings are wound directly on the primary…”. If this means that they are the outside windings, one might get lucky and be able to unwind several volts worth of the 8-volt winding. That voltage would of course also be lost at the high end of the output range.
I have two newer ZWs, one with 4 bricks for running trains and the other with three bricks for accessories, all work great. I can controll the track voltage on all tracks with the Cab1. But when I first turn on the power tracks two and three will be at the 18 volts needed to run TMCC. If I am running my conventional engines, I’ll place them on tracks 1 and 4 themn controll them with the Cab1. I also have DCS hooked up and can run my MTH engines to it. Or run the MTH engines in conventional with the Cab1 on tracks 1 and 4.
Chuck, Yes I did calibrate the ZW. I have seen the same throttle deadband on other modern ZWs.
Thanks to all who replied. What I was really trying to ask is what handle position (0-20) does the postwar ZW start applying track power sufficient to begin running trains. Throttle positions 0-12 on my new ZW is essentially all deadband at less then 2 volts output to the track and is therefore useless for anything other then stopping trains. All of the voltage ramp occurs between throttle position 14 and throttle position 20.
It sounds like the postwar ZW starts providing track voltage at about 6 volts as soon as the rollers contact the coil at a very low throttle position. Is that accurate?
As I posted above, the manual says 8 volts: “…these transformers have a fixed secondary winding of 8 volts in series with a variable secondary winding of 12 volts. This makes it possible for each of the four rolling contacts to supply from 8 to 20 volts.”
Here are some data points from measurments on my two postwar ZW transformers, using a 30 year old Sears analog voltmeter. The no-load output at the wall read 125 volts AC as supplied by BGE in mid-afternoon. If you think that reading might be a little high, adjust the values below accordingly. The transformers have had very little use since all rollers and pins were replaced a couple of years ago, but the windings themselves are old and certainly less than “brand-new clean” along the roller-contact paths.
On the two ZW’s the max output read 21 volts AC on all terminals, measured with no load, or 105 per cent of rated output.
The minimum outputs were 7.6, 7.2, 7.0, 7.2 and 7.5, 7.2, 7.0 and 6.9, to the best of my ability to read them. Make of these what you will.
My postwar Lionel locos run quite well when driven by these ZW’s, but as Earl suggested my modern dual can-motor Williams diesel as factory-wired (parallel) which will start at 3 volts or so, is a bit of a jack-rabbit when driven by these transformers.
You are definitely right about the deadband but are you using a commnd base and the CAb-1. This isn’t an issue for me because I operate exclusively using the remote cab1. I guess my ZW is more for looks. As far as flexibility goes it hard to beat the new zw.
I do use either the Cab-1 or DCS remote to control voltage to the track but I would also like to be able to use the ZW handles if they weren’t so dogone sensitive. I like to operate my postwar trains without all the fancy electronics of DCS and TMCC.
Unfortunately PW trains tend to run better with PW supplies and vice versa. While you can run modern equipment with PW supplies, you need to wire in fast acting breakers and possibly spike protection to keep the modern electronics from being damaged. Modern lower end supplies may not be able to handle higher current PW trains. Z-4000 and new ZW are fine products but while they look like the old ZW, they don’t behave like old ZW. The closest thing to the old ZW may be the MRC Pure Power Sine Wave units. They come in single and dual modes.
My CW-80 also has the lag. I like the CW-80, but it does not have enough power to run all my postwar and prewar trains. For example, my 675 will run several laps around the track and then the CW-80 will shut off power for a while (a few seconds) until the transformer cools down and then the power will come up slowly and the whole cycle will repeat.