Thanks for posting that, Rob.
I have one not-very-consequential correction: The drop in the RMS AC voltage is more like half a volt for each anti-parallel diode pair and therefore about a volt for the two pairs that one would make from one bridge-rectifier module. It's complicated to compute exactly and depends a little on the AC voltage put in.
A drop of about .7 volts per diode pair would be correct for a DC input.
Bob Nelson
the nitro man...A picture sure would help...
Rob
Can you please tell me how to use bridge rectifiers to do this? The only time I've ever used a bridge rectifier was to convert ac to DC current. A picture sure would help along with part numbers. Thanks Rob for your help.
the nitro man...I have lost the part number, because all of the links are dead now...
sir james II run my Williams with old ZWs and they are quick to start without a train attached. As an easy fix try putting a couple 18 volt bulbs in series with the track wires...
With the dual motored Williams & K-Line diesels, I've had great results wiring the motors in series. K-Line thought so highly of this method that they had a DPDT switch on the bottom of some of their later diesels(MP-15, eg.) to select between parallel & series operation.
I run my Williams with old ZWs and they are quick to start without a train attached. As an easy fix try putting a couple 18 volt bulbs in series with the track wires. It may not help but then again it might and its easy.
"IT's GOOD TO BE THE KING",by Mel Brooks
Charter Member- Tardis Train Crew (TTC) - Detroit3railers- Detroit Historical society Glancy Modular trains- Charter member BTTS
i put in four pairs of these diodes. it starts & stops great now with my zw transformer. http://www.radioshack.com/product/index.jsp?productId=2062591i also ran the smoke unit from the center rail hot wire & a frame ground & it smokes like crazy. if i hadn't redused the voltage to the motor with the diodes it wouldn't have helped much if any.
the nitro man ADCX Rob, what kind of diodes would i insert in diode strings in series with the power to the engine? how many would be needed? do you have a part number from radio shack that would work?
ADCX Rob, what kind of diodes would i insert in diode strings in series with the power to the engine? how many would be needed? do you have a part number from radio shack that would work?
Bob Nelson has spelled this out many times - here are his words:
lionelsoni However, the best voltage-dropping element that I know is a string of silicon diode pairs. They will give you a constant voltage. The simplest way to do this is with one or a few bridge-rectifier modules: http://www.radioshack.com/product/index.jsp?productId=2062583 Connect the + and - terminals together. Then use the ~ terminals to wire the module in series with your transformer. You can use the +- junction as an intermediate tap. If you need lower voltage, just add another module in series.
However, the best voltage-dropping element that I know is a string of silicon diode pairs. They will give you a constant voltage. The simplest way to do this is with one or a few bridge-rectifier modules: http://www.radioshack.com/product/index.jsp?productId=2062583 Connect the + and - terminals together. Then use the ~ terminals to wire the module in series with your transformer. You can use the +- junction as an intermediate tap. If you need lower voltage, just add another module in series.
ADCX Rob, what kind of diodes would i insert in diode strings in series with the power to the engine? how many would be needed? do you have a part number from radio shack that would work? i would like to wire it into the engine & not between the engine & power supply, so i can just run it on any line. how would i wire that in?
Bob, i do have TVS's, they ones you recommended is what i installed.
No transformer's overcurrent protection is going to respond until after your locomotive's electronics have already failed. The circuit breaker is there to protect the transformer itself and your layout wiring (if your wire is not undersized). For this, the thermal circuit breakers in older transformers are exquisitely appropriate, since they model the harmful heating caused by overcurrent.
Locomotive electronics are likely to be damaged by overvoltage, for which the appropriate protection is a transient-voltage suppressor (TVS).
Like Rob mentions you should go with a more modern transformer for at least three reasons; 1) the starting voltage is lower, 2) you get better circuit protection, and 3) you get better whistle & horn control.
The ZW type R was meant for post war trains to be run with, and doesn't have decent circuit protection for newer engines, in other words it will fry your electronics before it pops it's circuit breaker.
Since you have a Williams engine, go with either an Atlas O or MTH transformer, as these will work well with Williams by Bachmann.
Lee F.
The ZW starts at about 6 volts, the Williams engine will cruise at about 5-5.5 volts. You could use a modern transformer like the CW, which starts at 0 volts, or insert diode strings in series with the power to the engine(each anti-parallel pair will give you about .7 volts reduction).
On the flywheel issue, the loco should be disassembled and lubed well with synthetics(don't forget the side rod linkage too - this also puts drag on the drivetrain), and then broken in. They are very "stiff" when new and will take many hours to loosen up before you will notice the flywheel action. The Polar Express with a small flywheel took some time to "coast" from new - like a year! The Williams FM is about a year old & is just starting to coast a little.
i have a Williams 2-6-4 pink girls train set. it looks awesome & runs great but i have a couple issues with the engine. first off is the flywheel action. you would think with the big flywheel on the motor, it would have some flywheel action, but it doesn't. when the power is cut off, the engine stops. it's bad enough that it will derail cars.
the second issue is the smoke unit. i mean why even bother putting those smoke units in them? they don't produce any smoke. I've got an old tyco that will out smoke it. is there any upgrade smoke unit that will work?
i use an old Lionel zw275 R transformer. it runs great with this transformer, but it starts pulling just as soon as it gets power. the transformer doesn't start out at a low enough voltage & the engine will take off. the same about stopping it. the voltage is to high for it to make a nice stop. it acts like it slamming on the breaks because of the lack of flywheel action. is there anything i could do about this like maybe adding a resister on the motor to take some of the power?
it might sound like I'm not happy with it, but believe me i love this little engine. it just has a couple issues.
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