Your gremlins sound like bad electrical connections, possibly cold solder joints or a wire broken internally. Expect the gremlins to reappear soon.
When you have the cover off your KW, power it up with a load, such as a light, and wiggle the internal wires with a non-conductive object such as a plastic ruler and see if you can find an intermittent connection by observing the light for blinking.
Earl
OK,
This transformer has gremlins. A while ago I started running tests again, and really did nothing; All of a suddent both the C and D posts are hot again.
Now I jokingly attributed this to gremlins; actually I cannot explain the the unexplainable. But prudence and common sense dicatte that I do nothing more than put it back on line and don't question a good thing. If it malfuntions again, well, gremlins may be back at it.
Thanks to everyone who offerred suggestions. Perhaps this discussion will be of use in the future for anyone who may be having problems.
Prairietype (Mark)
Tonight it just got crazier. I'm not kidding.
The D post, which was dead previously is now active; the fixed voltage wire from the 022 switch lights up bright on this post. But now the C post is dead.
Previously, like last night it was the C post that was hot and the D post was dead.
I used the voltmeter (a $14 model) and U-A and U-B output is spot on.
I can actually live without the C post; as we run several switches from the D connection, and need the higherf volage to get a good tight snap when switching..
But, what can you make of the reversal of power? Anyone? This is really baffling.
Mark (Prairietype)
The better the voltmeter (the higher its impedance) the more likely you are to get misleading readings from an unloaded transformer. I would measure voltages with loads connected. I would remove the warning lamp as well.
(A little terminology: The thing that is being called the "core" is actually the transformer itself. The core is the magnetic circuit, made of iron laminations, and does not include the copper windings. The copper thing that the carbon rollers roll on is part of the secondary winding. The KW, although called loosely a "transformer", is actually a box that contains the real transformer, along with switches and other minor components.)
Bob Nelson
Get your voltmeter and check for AC volts between the core where the 'D' terminal wire is soldered and to the 'U' terminals. If none, check for voltage on the exposed core itself, on the section that the rollers contact. Check near the end, where the wire for the 'D' terminal gets connected. If you get voltage there, but not on the wire terminal itself, then there is probably a bad solder connection on that wire terminal. Unplug the transformer, heat up the joint, apply fresh solder to the joint and try again.
You may first want to check for continuity with the transformer unplugged. Check for continuity between the 'D' wire solder connection on the transformer core, and anywhere on the exposed section of coil. You should get a reading. No reading is a definite bad connection at the solder joint. Reheat, resolder and check again.
Larry
That is what I have done. Asa mentioned, the C post is hot and works, but the D post shows nothing. I also connect the constant voltage plug directly to the core at the D post attachment point and got nothing there, either.
Bob and Earl,
I will take your advice next. There is no logical reason why there shouldn't be constant voltage coming from the core, if, the U-A and U-B terminals are live. And electrical theory is fundamentally logical, at least with these technologies.
I have a very nice voltmeter which I will use to test as you suggest.
If you are able to get voltage between terminals U and A or between U and B, then you should be able to get voltage between U and a point on the exposed transformer winding, since that's what A and B are connected to through the carbon rollers. Are you making all these voltage measurements with or without loads on the transformer? If the circuit breaker is stuck open or disconnected, you will measure voltage with a voltmeter with no load, through the warning lamp, but nothing with the load connected.
Prairietype 0I manually made a jump from voltage plug to the lamination assembly and got nothing (not a spark or a glimmer from the bulb on the switch.
0I manually made a jump from voltage plug to the lamination assembly and got nothing (not a spark or a glimmer from the bulb on the switch.
Are you sure you got a good connection to the coil when you did your test? Coil wires are covered with shellac to insulate them. Even though the wire appears to be bare, they are, in fact, insulated.
That's true about being grateful that it is not one of the variable outputs. As I mentioned we would like to have the full power output, but we have three KW's line up inn a row, and two of these will handle the power output as we have the layout fairly even segmented. And there four additional 1033 transformers and two R's to handle sidings and spurs, etc.
I just like to have everything functional (it's my quirk) and maybe I'm missing something obvious, but overlooked. But to re-emphasize, the binding post is tight and unbroken and the wire connects internally to the primary coil and lanimation assemby at the heavy copper mount.
To Larry: We're using the constant voltage feature provided from the C or D posts to provide voltage to the switches. This is single wire connection. I manually made a jump from voltage plug to the lamination assembly and got nothing (not a spark or a glimmer from the bulb on the switch.
I agree Larry, which is why I said "if you've verified the wire all the way in". Other than one totally smoked KW, I've never seen one with a bad coil. I've seen them with a lot of wear from bad rollers, but I managed to rescue those.
Looking at the diagram, it pretty much goes right to the transformer secondary. If you've verified the wire all the way in, I'm not sure this is something you can fix. OTOH, it could be worse, it could have been one of the variable outputs!
Once again I am working on one of our club transformers. The D post (constant) voltage) is dead.
I took the shell off and checked the connections behind the panel, and the wire is attached as it should be. The other end is well soldered to the coil and laminiation assembly at the core (at the point indicated in the Greenburg repair guide).
I even tried a connecting an accessorry wire (from a voltage plug on a switch) to this point on the core to see if I could get anything directly from there. No luck. So I do not think it is a bad internal wire.
The C post power is fine, albeit lower voltage as per design. In every other respect the transformer operates fine. We would like to have full capability for the mall layout available from this transformer.
If anyone has any ideas about this problem I would surely appreciate hearing what you think,
and thanks in advance.
Prairietype
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