10 replies to this topic

[Emax]

Eagle Point:
A recent power surge has disabled two POMA LED / Alphanumeric fault display units - vintage 1985. These are the kind used in conjunction with the VIGI.

Poma has none of these and says they won't. Would like to get this system working while a complete replacement is being considered.

Contact Bud Fischer or PM Emax

[iceberg210]

I don't know if you've tried them or who you would talk to but I know Durango Mountain Resort has those vintage of Poma's and that they pulled out one last year in fact, so they may have some parts laying around. Also it's not too far away from you guys, hope you can find what you need.

[Emax]

iceberg210, on 26 December 2010 - 06:07 PM, said:

I don't know if you've tried them or who you would talk to but I know Durango Mountain Resort has those vintage of Poma's and that they pulled out one last year in fact, so they may have some parts laying around. Also it's not too far away from you guys, hope you can find what you need.

Tried calling, but could not get in touch with an appropriate person. The secretary seems to be in charge of all technical matters there.

[Emax]

Thanks for all the tips, guys. I think this problem may be solved.

[Nate214]

Those damn things are on three of our chairs and I think only one if them displays anything and the other two u have to look at thelight and number on the fault list and the vigis suck too lol

This post has been edited by Nate214: 29 August 2011 - 03:23 PM

[Emax]

I'm no avid fan of the VIGI - never was - but at the same time, I think it's unfair to poke uninformed fun at the serious work of yesteryear engineers - unless you are one and have a better idea of your own to offer.

During the seventies and early eighties, tradition and a lot of pressure from certain European security-circuit Nazis forced us all to dream up clever schemes to find a "hole" in a 2-mile long series circuit. There was to be only one wire into which all towers (and in the case of VIGI, stop buttons, etc.) were connected in a string. The purists insisted that this was the only truly safe circuit - which is probably true... until the thing gets bypassed with a single jumper in a fit of Saturday afternoon frustration. In time, cooler heads prevailed and the far more practical one-circuit-per-function became the norm and built-in bypass was invented (credit YAN for this).

Among the "cute" locator schemes used were several variations on voltage dividers to ground (YAN and others), capacitance between two steel cables spaced 6 ft apart that spanned the lift line (Frey Equipment) and the French VIGI. All of these methods suffered the same fatal flaw: they could present the user with the WRONG information - which is far worse than NO information, if you think about it. An idiot can find a problem in a 20-tower circuit with no more than a volt meter if he's willing to climb five towers - but assure him that the problem is on tower nine, when it's actually on tower fifteen and he'll be there all day or longer.

VIGI, however, was quite clever - borrowing a technique long used by telephone companies to locate faults in their cables: time delay reflectometry. An electronic pulse is sent down the conductor - it reflects off the far (open) end and returns to the testing end. The propagation rate of this pulse is a known quantity in any particular conductor, so by timing the period between the initial pulse and its return to the point of origin (and dividing by 2), we can determine the distance between "home" and the open end of the wire. Each tower and pilot device would be a specific distance from the point of test - these distances would be recorded at the time of installation by actual test. The VIGI panel went a bit further than just offering distances though - it associated each distance with the alphanumeric name of the device located at that point in the circuit, displaying it on a small screen. Pretty neat trick for that period in time - or even for this one. Unfortunately - for POMA and the rest of us - resistances to ground on the safety line could foul the data and send you searching in the wrong place. Further, this neat piece of electronic magic did not care for either lightning strikes or ham-handed pseudo-techs attempting repairs - eventually, they all fail... and lately replacements cost $10k - if you can find one.

So yeah, it was not the best solution for the problem at hand - but it was a product dictated by its time and a damned fine piece of engineering.

This post has been edited by Emax: 31 August 2011 - 08:34 PM

[Lift Dinosaur]

Thanks for your view, experience and evaluation, Bud. I don't think any of us still have our 486Mb computers...or even know what they were.
Dino

[Razvan]

Not sure what the 486Mb computers were, but... ahem... I still have my first computer, a 386SX laptop (Zenith MastersPort, 10/20 MHz, math co-processor socket, 2 MB RAM, grayscale VGA LCD monitor with color external output, integral modem), bought SH (or TrdH, FthH, don't know) in 1997. I start it from time to time, to remember writing my thesis in Word 6.0 - under Windows 3.1. I've even used the thing for my final project presentation - an interface allowing communication between two computers via serial-to-audio to/from two amateur radios (AX.25 protocol). And to be mindblown seeing the ORIGINAL CMOS battery (NiCd) keeping time since 1990 or so.

As recently as two or three years ago I was using it to test my QuickBASIC knowledge with a board of 8 relays driven by a ULN2803, but the project was cancelled by the arrival of a new washing machine.
(Yeah, I've pimped my mom's old lean mean top-loading washer with a parallel port.)

No words from the Smithsonian so far. They're probably still wasting time on that boring shuttle.

[Nate214]

Yes the vigi in it's day was definitely advanced and probably worked well. I'm just being sour as our comlines age the vigi acts up with random indications which sends us up just about every tower. A neat trick with pinpointing the problem area is to install a jumper on the line coming in to the line going down and this will bypass the line above you ( if a bottom drive top drive reverse direction ) if the problem goes sway then the problem is down the line if it stays the same then your to far down the line. Or you can just jump the tower across the resistor to see if it's the tower your on. That's the only way we can troubleshoot these most of the time if we are lucky the vigi will send you to the right place. But so many burnt out resistors over the year hardly ever get a twr number usually will just read open line.

[Emax]

Nate214, on 02 September 2011 - 10:38 AM, said:

Yes the vigi in it's day was definitely advanced and probably worked well. I'm just being sour as our comlines age the vigi acts up with random indications which sends us up just about every tower. A neat trick with pinpointing the problem area is to install a jumper on the line coming in to the line going down and this will bypass the line above you ( if a bottom drive top drive reverse direction ) if the problem goes sway then the problem is down the line if it stays the same then your to far down the line. Or you can just jump the tower across the resistor to see if it's the tower your on. That's the only way we can troubleshoot these most of the time if we are lucky the vigi will send you to the right place. But so many burnt out resistors over the year hardly ever get a twr number usually will just read open line.

I feel your pain. Why not implement something better? It would be worth the trouble.

[Nate214]

We tried to get it done last year but company didn't want to. But sure we will have to eventually. Our Yan that's going up next year will be the most upgraded drive and controls we will have. It will be a sweet new old lift.