ZW TransformerWhistle Question

[intermission]

Hi, before I explain, I am a newbie.

I just received a ZW(R) perhaps transformer I purchased. ( I say perhaps because ZW(R) is on the bottom plate).  Anyway, the whistle slider does not operate my lionel locamotive tender whistle. When I push the slider forward it accelerates the locamotive a decent amount but does not blow the whistle.  The slider works the neutral and I slowly moved the slider forward to try and find a spot where the whistle might blow.  I attached the lionel powermax plus transformer that came with the set and it works fine.  Could this be an issue with the ZW or could the tender not be compatible with the ZW?  I have a return option on the ZW if it is malfunctioning.

Thanks

Chris.

[jwse30]

I'd try reversing the wires. The whistle controller works by sending DC voltage through the track, along with the AC voltage that the train runs on. If the wires are reversed, the whistle may not work because it is looking for the +DC voltage, and is getting the -DC voltage.

 

If that doesn't work, try the other handle, hooking up the two wires both ways. If it works on one handle and not the other, the transformer needs a bit of work.  I think some early K-Line engines had a special whistle button that was required; everything else should be compatible to the best of my knowedge.

 

Hope this helps,

 

J White

 

[kpolak]

I need to clean the metal contact at the whistle switch from time to time.

Kurt

[intermission]

Thanks for the response, I did try reversing the wires and did test using both handles but still got the same results.

[lionelsoni]

You may have bad diodes in the transformer's whistle circuits; but it's a little surprising that both of them have failed.  They use obsolete copper-oxide rectifier diodes, which you can replace with modern silicon diodes if you want.

The proper wiring to make a modern whistle blow is U to the outside rails and A or D to the center rail.

Do you notice two stages when you move the whistle control?  There is a first stage when it adds an additional 5-volt winding and the diode in series to the output, to give a strong positive DC component to the center rail, intended to operate the whistle relay initially, then a second stage when it shunts that diode with a resistor to restore much of the AC component and to drop the DC back to just enough to keep the relay operated.  This doesn't matter for your modern whistle; but, if you're not getting what I described, it may indicate some problem in the transformer's whistle switch.

[intermission]

I don't believe I am getting what you described.  When I move the whistle control forward the locamotive accelerates very noticeably and never reduces this speed until I release the slider.  I held the slider forward for about 20 seconds and it never seemed to get to a second stage that you are describing.

 Thanks

 

[bfskinner]

intermission

I don't believe I am getting what you described.  When I move the whistle control forward the locamotive accelerates very noticeably and never reduces this speed until I release the slider.  I held the slider forward for about 20 seconds and it never seemed to get to a second stage that you are describing.

 Thanks

 

It isn't the time you hold the "slider," it's the distance that you move it. As you shove it forward, it hits one contact and then another.

Check here under "Transformers," "ZW-R" and "Whistles/Tenders." There are some further complications that are introduced by modern-era electronic whistles, but this should be a start.

http://pictures.olsenstoy.com/searchcd1.htm

 

[intermission]

I put a meter on the track to test and when the slider is pushed forward it provides a 5 volt increase on the track.  It doesn't appear that the second stage to drop the DC back to just enough to keep the relay operated is happening.  From what was being described I guess I would expect a drop in the voltage if it worked correctly, am I wrong?

[Anonymous]

The best thing for you to do is take the ZW and have it serviced. Something is not right inside the shell. A good cleaning, and servicing, never hurts.

[A&Y Ry]

Order a couple of anode-to-case, 40 amp, 600volt, Stud Diodes [rectifiers]from ALL Electric, Inc.- About $3-4 each and replace your exhausted selenium or copper disc rectifers. Just google All electric.

[intermission]

Thanks for the help, really appreciated.

[lionelsoni]

It's acting as if the rectifier diodes (always copper-oxide, never selenium, in my experience) are both shorted.  Before you get replacements, it might be worth checking whether someone deliberately put shunts around them, in order to turn the whistle control into a voltage-booster.  It is suspicious that they both would fail in the same way.