Strange Railsounds Bell / Post War Whistle Issue with newer ZW

[Anonymous]

Finally got my layout up and running after waiting for many years. I have been running Rails Sounds 1&2 steamers and diesels along with Post war Steamers with Air Whistle for weeks now. Today I get my Newer Jersey Central Madison Passenger cars out and connect them to my 2056 with air whistle. Whistle seems to get stuck. So I put on my Railsounds 1 tender on the 2056 and the Bell is stuck. So I switch out power supplies from a 190w to a 135w, worth a try. Still have issue. Finally I remove all the passenger cars and problem gone. I strat adding them back. Once I get 2 illuminated madisan cars behind the engine the problem comes back. I can pull 20-30 freight cars and no problems. What is the Deal?

I am going to try my Newer Railsounds 2 engine now and also my other loop.

[Anonymous]

OK my railsounds 2 engine does not have the issue. If I put maddisn car on a different loop with air whistle even with no engine, just 2 cars and the whistle and it makes the whistle go off. The cars themselves if they are on the track by themselves they make a buzzing sound. This is first I have run with new ZW. I used the cars under the Xmas tree with Cab 1 and powerhouse and did not have issue. Seems something between the ZW and the cars. Lionel did replace the circuit board in the ZW shortly after I got it. One side, left I think, was not working. I am going to take the cars apart and see how the lights work. I think it just has 2 very small bulbs. Must be some how sending DC down the line to trigger the whistle / bell. ???????????????/

[Anonymous]

I took it apart and it seems to have an attempt at a constant voltage circuit. It uses single diode which I am going to try and change to bridge rectifier. Guessing the buzzing is from clipping of the AC sin wave (I had a little electronics background). Bulbs used are 12v and 14v but the car is getting close to 20v from my ZW. Buzzing goes away at near full ZW throttle.

Anyone else have anything like this ?

I will report back but Pistons Playoff game is on tonight so might be tomorrow.

[Anonymous]

Ah ha, the diode is producing dc and dc is what activates the bell or whistle.
If the engine has old air whistle, it does not matter what polarity of dc offset gets on the track as the dc can get through the coil with the points and once the points close the ac goes right to the motor.
If it is an electronic horn, + dc is for horn and -dc is for the bell.
Get rid of the diodes, they are feeding dc back on the rail.
You need to get a volgtage regulator or just put in bulbs of the max voltage you use and you will be fine. Dave.