BCD thumbswitch replacement

[ScottI2R]

Hi all,
OK, I got caught doing nothing @ work so it has been suggested (again) that I look into replacing the BCD thumb switches that we have been using (reliably I might add) for 20 years! In short, we gang 3 and 4, 0-9 bcd thumb switches together. Effectively allowing a range from 0-199 on the three switches and 0-9999 on the 4 switch The "hundredth" digit is mechanically blocked from exceeding the "1" value. the whole point of this is to control a pulse generator with variable on and off time as determined by the switch settings.Each switch is read separately and the switches i/f to CMOS ckts.
My question is: Does anyone know where I can find a more "modern" BCD switch, perhaps LED/LCD that would replace this "antique" looking switch? It must i/f to the current circuitry and be as easy to change the values as the flipping of the current switch. The whole point of this is to give a modern appeal to a current product that we sell.
I can understand this when a customer comes in and says,"Jeez! Where are the vacuum tubes!" (Let it be known that the SAME customer later stated that "It's the best running system we have! You know it's good when the operators say it's a joy to run!"

I tried searching the web, but I cannot seem to find what I need.

Any help would be appreciated,
Scott

Oh:"They HAVE digits" is not a good answer to tell the Boss when he says look into making them digital!

In a hundred years, it isn't going to matter anyway.

 

[Skogsgurra]

Does the replacement have to be a drop in part? I mean, no new cut-out, no new nothing.

My feeling is that the whole thing needs not only a face-lift but a total redesign. Circuitry that worked with thumb-wheels used to contain very hard-to-get ICs. What about production of new systems and what about support?



Gunnar Englund

http://www.gke.org

 

[itsmoked]

skogs has the right questions. Now days you stick up/down switches and a display LED/LCD. Look at the switches with a micro, drive the display with same, and if needed, present BCD outputs. Usually you can put the display to all sorts of gee-wiz utility while your at it.

 

[ScottI2R]

Skogsgurra,
It doesnt have to be a "drop in" as far as sizing and cutouts go. There is some room to move things around. Ideally, an electrical drop in would be perfect. Currently, we are not having any trouble obtaining IC's such as: 4002,4522,4082,4077,4518, or 4016's. This is pretty much the IC's these I/F with. I agree with a re-design but that is NOT even going to be considered.
They want limited expendatures on this and are even balking at the panel view costs to replace the PB box.
Actually, a new product is being considered when the R&D budget says so. (Soon as I find the KVA on this one mutant transformer as well.) This wont affect the one I have the question on though. It will be slighly smaller in output.
I think you would call the new one a "middle of the road" unit.

Thanks,
Scott

In a hundred years, it isn't going to matter anyway.

 

[ScottI2R]

Yeah smoked,
That's how we do it with our newer units. This unit has absolutely NO S/W, F/W whatsoever. Just a plain, dumb, self contained EDM generator. All H/W. But really does work great as it is. And it still has it's market niche and customers really love'm. I think we should leave it alone but I'm just the dog and when I'm told to go potty outside, well, I go potty outside.

Thanks,
Scott

Hmmm....maybe a small micro......they wont let me but i'll push!

In a hundred years, it isn't going to matter anyway.

 

[VEBill]

There is a spectrum of options from do nothing to a new uC to replace the whole darn thing. You probably need to do a trade-off study to figure out exactly which option is best overall. Let loko mgt decide which option they like for further study to confirm the budget, risk & schedule.

I doubt you'll find anything truly off-the-shelf.

 

[itsmoked]

hmmmm there's always:

http://www.nkksmartswitch.com/partselector.asp?S2=0

Let us look closer at the micro solution...

(10)pieces mentality

Circuit board $8
2X16 LCD $14
Middle of road PIC (internal osc) $4
Nice up down button x 2 $1
Power supply (freebie) $0
connectors? $2
full front overlay label $4
face plate silkscreen (replaced) $-6
-----
$25
This would *plunge* with quantity.

Now you have to ask yourself, "am I feeling luckXXXXX"
Strike that(wrong venue) "is this on par with the cost of a bunch of antique thumbwheels?"

If you are replacing more than one thumbwheel set, which you can easily do with this scheme, add a "channel" button $0.50 for each.

You can bring the picture(product) up to customer expectations. Probably charge a little more. And, AND! You can use this interface with little change for your future 'modern design'.

 

[Skogsgurra]

Yes, Smoked.

And if you remember to use a micro with nonvolatile memory, you do not have to re-enter information everytime power has been removed.

Gunnar Englund

http://www.gke.org

 

[itsmoked]

Twas ass-oom-dah.

 

[Skogsgurra]

Assumed?

Gunnar Englund

http://www.gke.org

 

[VEBill]

Fully burdened NRE - mid-5-figure range ?

Manuals need updating.
R&O updates
*.*...ilities.
Developement system
Learning curve
Software version 1.0
Software version 1.1
Software version 1.2
Case of beer
Software version 1.3
etc.

 

[itsmoked]

Yes assumed..

VE1BLL.... He needs work! Don't bring up those kinds of concerns!! Besides his time is already burdened.. Solitare, Tetris, Eng-Tips, etc. etc.

 

[Skogsgurra]

Stop hitting my head willya?

Gunnar Englund

http://www.gke.org

 

[itsmoked]

Trying to fix that loose eye..

 

[ScottI2R]

Thanks all,
Just had an amazingly simple idea in the midst of a hugh headache! Momentary pbs to a 4510 (clock input)which in turn drives my cmos bcd inputs on the pulse generator and a 4511 to drive the led display. A toggle to determine count up or down. NOw just have to work on "storing" the values in the event of power down/loss( Could be something HIGHLY desirable to most customers!)
Cheap solution too!

Jeez, why do I over-complicate things...
Oh, smoked, you left out "EBAY"

Thanks,
Scott

In a hundred years, it isn't going to matter anyway.

 

[itsmoked]

DOH!

Sorry to hear of the headache. (they suck)



Look into digital potentiometers ICs. They often remember their settings.

http://www.analog.com/en/subCat/0,2879,761%255F797%255F0%255F%255F0%255F,00.Html

http://www.maxim-ic.com/DigitalPotentiometers.cfm?ref=ms1

http://www.intersil.com/products/deviceresults.asp?i=10763