Oil Derrick Surges

Truthfully, I'd just use a small transformer for it, it's easier that way.

I tried different things like DC conversion and a capacitor, could not get satisfactory results. I agree with John,run it separately.  Not only that it generates voltage spikes not good for accessories with chips. If you get a solution ,please share it.

Dale H

I'm just not seeing a "perfect" solution to running it with a lot of other stuff in the mix.  A 1033 is only around $20, and it solves the problem completely.

I ended up using an old 4660 transformer. I hooked up the oil derrick to the fixed AC posts and everything works fine.

Sounds like a plan.

Although you have solved the prolem , there is another thought and it is how things are wired.  If all non-operating light only acessories are wired in daisy chain parallel, then you would not notice any light intensity change (unless a light blinks on/off of course).  If you added an operating acessory at the end of the daisy chain then the wiring resistance comes into play so that an operating acessory  high current spike results in a voltage drop and lights flicker for duration. 

In theory if all operating acessories are home run wired back to an adequate or over adequate "stiff voltage/current" power supply,  then lights and other acessories would not flicker preceptiable. 

Same thing as several houses wired to same pole transformer.  When neighbor starts his microwave, big power saw or hair dryer, your lights and appliances don't (or shouldn't) flicker with neighbor's current draw (in theory).  Iam sure joureyman electricans will jump in here.  Just a thought. 

Well, the difference between the house transformer is that the standard one is a 50KVA unit.  The microwave draws maybe 1500 watts maximum, so that's about 3% of the capacity.  Add to that that there's a true home-run from their house and yours directly to the transformer, and there's little chance for a significant change.  I can't comment about higher current draws from the pole transformer, mine is exclusive to my house, I have 400A service here.

Take the transformer in question, the ZW puts out maybe 220-230 watts maximum, the 275W is the input power specification.  If you have an accessory that is drawing several amps, it could easily be using 15% or so of the transformer capacity.  There's a much greater chance that you'd see an effect of the sudden switch on of that kind of current.

I just tested this theory, I connected an 8 ohm resistor and my voltmeter across the KW.  With a 2A load, I had 17.6 volts from the transformer, when I added another 8 ohm resistor, the voltage dropped more than a full volt to 16.5.  I repeated this test with a PowerHouse 135W brick, and the voltage dropped slightly over 2 volts.  Yes, the lamp that I had connected did indeed change intensity, it was clearly visible.

Sam, I am a mechanical engineer but my electrical skills are limited. I understand wiring in parallel and wiring in series but I am not familiar with daisy chain parallel. Perhaps you could splain. All of my switches, lights and oil derrick are wired in parallel. I have (2) 1 foot long terminal strips with jumpers sending wires to every light and accessory. I will stick with the separate transformer but I was hoping for a more impressive solution that I could brag about to my electrical engineer friends.

What I meant was starting with a set of parallel wires from the transformer to first accessory terminals then a wire set from this first accessory to second acessory, from second to third to fourth accessory etc., sort of like a rope draped from place to place to place. 

However it appears you are doing home runs from a central feed via the two terminal strips tied to a properly sized (I assume) transformer.  Given the nature of train layout wiring, there is no really good work around to eliminate light intensity changes, other than having all "static" lighted buildings and lighting going to a dedicated transformer.  And then to a point of absurdity, a dedicated transformer for each operating accessory so its operation never cause other accessories to wink/dim/flicker or slow down.

I suspect that most accessories don't cause the issue.  My guess is there is quite a bit of current draw when the oil derrick solenoid pulses the pump.  Short of a much beefier transformer and #12 wiring to the terminal strip from the transformer, I'm not sure there's a ready solution.

Did you happen to measure (or know) the current profile and voltage requirements for this accessory? Does DC work?  It seems odd a manufacturer would make a layout accessory that de facto needs its own transformer. We all accept/understand the layout lighting flicker on the occasional switch-throw but a continuously operating accessory that pulses the lights every few seconds?

Surely someone has come up with a more impressive solution than the separate transformer. 

Separately, there's the occasional thread musing about the behavior of the bubbling tube in some derricks. Apparently one concept is to run the heater for a few minutes at a higher voltage to get it bubbling, then dropping it a few volts which runs the mechanical part at a more pleasant speed. So perhaps any solution could deal with that too. As to whether the extra cost is worth the bragging rights is a separate matter... 

I don't know, a cheap transformer seemed like a pretty impressive solution.   It's simple, easy to implement, cheap, and it works.

Agreed, can’t argue with keep-it-simple … but where are the bragging rights?

There’s a credit card TV commercial where they go through the prices of things you can buy but the final example suggests it’s all about the non-tangible value which is priceless.  I’m thinking about an ME showing up his EE buddies on their home court – bragging rights, shock-and-awe, or whatever are non-tangibles which can be priceless. 

Life's too short to try to accumulate bragging rights.

Your DC configuration should be a resistor BEFORE the capacitor, and then the shunt capacitor.  The resistor will limit the peak and steady-state currents, and the capacitor will provide the surge current needed to pull the solenoid plunger into place.  The size of the resistor should be such that the solenoid will hold (without the capacitor), but not pull in.  I would guess around 10 ohms +/-50%.  This will need to be much more than a 1/4 watt resistor.

You might also want to wire the heater bulb as a separate direct circuit.

All this to save a small transformer?