Bought a Miller engineering sign today second hand at an antique mall. The chase lights work but there is a dark area that is not lighting up. Any thoughts on what might be causing this.
I had tried that. It is in a desktop mounting so it is a little harder to do. Part of the area is lit but it is spotty kind of an irregularly shaped cresent arc along the side. Do the units normally make a high pitched sound when operating? Noticed that.
The power supplies of the type used for the signs can make a high pitched squal. Not everyone can hear it.
A dark spot with the rest of the same section lit up fine usually means the EL material has been damaged in some way in that area, Probably not fixable. But drive past nearly any strip mall, SOME store will have a burned out section of their sign.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
rrinkerThe power supplies of the type used for the signs can make a high pitched squal.
I have maybe six different Miller signs and the 15-20Khz (or higher) pitch comes from something on the controller board. Some signs are worse than others. I had to make a foam-padded box for the Zippo sign. I could hear it across the room and the pitch would change as the sign stepped through each lighting progression.
I put a tiny dab of DeoxIt on the flex-PC strip before plugging it in. Maybe that will help? Otherwise, as Randy says, maybe the luminescent sheet has been bent or otherwise damaged.
rrinkerBut drive past nearly any strip mall, SOME store will have a burned out section of their sign.
My Miller "Union Station" Travel by Train sign has an option of replicating a flickering neon segment for part of the sign. It really looks realistic
Is there a way to get to the PC board so you can push the sequence button to try different sign functions? Maybe running the sign through it's cycle will show you if it is the EL or another problem. Or email Miller signs and ask.
milleren@microstru.com
Cheers! Ed
The Oscillator is what makes the noise. Oscillators are electronic circuits that generate a continuous periodic waveform at a precise frequency. An Oscillator is basically an amplifier. That said, the larger the sign and the more enclosed the PC board is in a structure the louder the high pitched tone will be. I have 11 of those signs in varying size and only experienced one with a problem. It must have been a poor solder connection to the PC board where all the wires are connected. Found that by shimming the connector with a slice of styrene in the side of the connector and board solved the problem......but it was not an easy find...... Miller may help, worth a call......were it Me.
If You think Yours may be loud.....LOL... Hear this Santa Fe large sign.....I inadvertently made it worse by sticking(the PC board) it in basically a styrene box...it's behind the closed dock door in the building:
Good Luck!
Frank
Yes, it's used as a voltage step-up - EL strips need HIGH voltage (but not really high current - but still not a good idea to touch the connectors). You can;t just step DC up, first you have to make it AC by running an oscillator, then it can be stepped up and converted back to DC. Way back when I had this kit from Radio Shack that had 5 neon bulbs on it, it ran off a 9V battery. Neon tubes need soomething like 80+ volts to work. AC, th flow will be between both terminals you can see inside the lamp, DC, it will surround one or the other. It had a very simple single transistor circuit plus a small transformer to generate high enough voltage, and I could always hear this 'sing' when power was applied. If yoou touched one of the neon bulb leads, you most definitely felt it, but it too was low current and not particularly harmful. The real danger of such things is if the current passes across your body, across the heart, where it can disrupt the signals to the heart. That's why you insulate yourself from the ground and use only one hand - you may badly burn a finger, but a badly burned finger beats a stopped heart any day.
Not that either the Miller signs or the neon circuit I had would actually be capable of burning you. They are quite safe to use. Don't want to scare anyone out of buying Miller signs, they are pretty cool.
Update- I was trying to get a photo to post but could not really get one that showed it well. How does a damaged board react? The chase lights work fine (it is the Dr Pepper one) It seems strange that the middle would be not working with a damaged board- you would think damage would be to the edges. (plus it is one of the types in plexiglass cases- kinda hard for it to hit something) The lighted area is crescent shaped on the edge but a speckled line with some lighted spots- very irregular. How sensitive are these on voltage level? There was some corrosion on the battery springs and the batteries I used were heavy duty rather than alkaline.
Again, I ask if you have tried pressing the sequence button* to see if there is any difference in the animation of the display. There must be some way to access the button to change the animation?
* Shown in the upper-left of the bare-board shown in RR-Mel's photo.
https://lights4models.com/product/2681dtn-model-dr-pepper-animated-lighted-dtn-version-by-miller-signs/
Clean battery contacts are a must. Another good use for the DeoxIt I mentioned (or CRC-26) a tiny dab on battery contacts helps with conductivity.
Good Luck,
Ed
Going to clean contacts and try new alkaline batteries. Hopefully it is simply low voltage sensitive. Sorry I forgot to say on the sequencing button- this doesn't seem to have one. There is a momentary contact one on the front that just lights it up- does not change sequence. (It is a desktop model and done different than the ones they have now it is in a square box with a plexi top on it) I did not see one on the board just an on and off and the momentary contact which is on wires away from the board. Jim
The sign is made up of layers - a phosphor layer sandwiched between two electrode layers. When voltage is applied to the two outer layers, it excites the phosphor layer causing it to glow.
If the phosphor layer becomes damaged - from bending / pinching - the phosphor layer becomes damaged in that area and will no longer glow. Sounds like yours somehow got pinched in that one area.
Mark.
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