Lamp Controller

Hello- I got coerced into creating a 4 digit sign where the digits are

2' square. The numbers won't change often, maybe once a week as it is a "we have raised this much..." thing. What can I use to simply (ie. cheap as I will probably never get paid) display the digits? I am considering using string lights, like XMas lights as the bulbs, so about 24V/ segment.

All help appreciated.

Scott

Reply to
ScottL
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I was looking for a big display like this for an outdoor wind speed indicator at a paraglider flight training area. Never found exactly what I was looking for, but for an outdoor display the best bet seemed to be a flip-dot type display. The dot matrix type are just a bunch of 'dots' that are electromagnetically flipped to show either a reflective side or black side.

Actually, I just found this:

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Which is pretty much what I was looking for and never found. They offer

7-segment displays up to 18". Might not be cheap enough for your application. Mine was to be solar powered, so power consumption was important... these should only draw power when changing.

Of course, if you only need to change the digits every week, what's wrong with flourescent construction paper? =]

Scott

Reply to
Scott Miller

Hi, Scott. If you're looking for minimum cost/high reliability, you might want to consider manufacturing some small flip cards with numerals on them (card stock works well for this), and affix them to some rings mounted on the upper part of the display. If you use a printer to make your numbers, it can look pretty good, and is about as reliable as you can get. Flip cards over to get to the right numbers, and you're there. I've seen it done effectively for church fundraisers.

But, if you've just got to have an electronic display, I'd go with some of the 3" 7-segment LED displays from Jameco, along with a 6VDC 800 mA wall wart, a bag of 220 ohm resistors, and four $0.89 DIP switches to manually set the segments. If you combine that with an 8" wide protoboard, you can do the whole electronics part for about $46 bucks plus shipping. Whoever is changing the numbers will have to use a pencil to manually turn on each segment, but that's doable by a non-technical person, because they can see the segments light up. A small instruction sheet with pictures of the segments and what DIP switches to turn on for which numerals will work OK for minimum cost. Each digit will be wired something like this (view in fixed font or M$ Notepad):

  • o-----o-----o-----o-----o-----o-----o-----o | | | | | | | | | | | | | | | o o o o o o o o '\ '\ '\ '\ '\ '\ '\ '\ \ \ \ \ \ \ \ \ o \ o \ o \ o \ o \ o \ o \ o \ | | | | | | |
6VDC .-. .-. .-. .-. .-. .-. .-. | | | | | | | | | | | | | | 220 ohm| | | | | | | | | | | | | | X 7 '-' '-' '-' '-' '-' '-' '-' | | | | | | | V ~ V ~ V ~ V ~ V ~ V ~ V ~

- ~ - ~ - ~ - ~ - ~ - ~ - ~ |a |b |c |d |e |f |g | | | | | | | o-----o-----o-----o-----o-----o-----o-----'

- created by Andy´s ASCII-Circuit v1.24.140803 Beta

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You'll still need an enclosure, some standoffs to mount the protoboard to the front of the enclosure, and some red plexiglass to put in front of the LEDs to improve contrast and get them their display without seeing the rest. That's your pidgin.

Here's a parts list:

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DISPLAY 3", 7-SEG, C.C.RED, 1 DIGIT Jameco #: 202542 MFG:LIGITEK MFG#:LSD30155-20/A

1+ $5.49 USD

TRANS,WALL,6VDC/800mA,F2

2.1mm X 5.5mm,UL,BLACK Jameco #: 147707 MFG:JAMECO RELIAPRO MFG#:DCU060080C6961 1+ $4.95

SWITCH,DIP,SPST,8SWTH,

16PIN,50VDC/100mA,SKT:37372 Jameco #: 38842 MFG:JAMECO VALUEPRO MFG#:DS-08-G-01-BL 1+ 0.89

@ CARBON FILM RESISTOR, 1/4W 5%, 220 OHM, (SOLD IN BAGS OF 100) Jameco #: 30470 MFG:HONJU MFG#:R220/100

1+ 0.99

PROTOTYPE BUILDER,5.5"X8.0" PCB,PRE-ETCHED,DRILLED, GOLDSUN Jameco #: 206594 MFG:JAMECO VALUEPRO MFG#:PCB-594

1+ 14.99

If you can scrounge the wall wart and the perfboard, the price goes down to $27 plus shipping.

Some times these things happen. I guess it comes from wearing the "nice guy" sandwich sign ("nice guy" on the front -- the back of the sign says "kick me"). Even so, I still wear the sign, too. ;-) Good luck Chris

Reply to
cfoley1064

There's a large 4 digit 7 segment Led display (11" x 5") on ebay. Item: : 3865333472

Reply to
rmigliac

Hi Scott,

Here is another low-tech alternative:

Place numbers on a word processor document. 0 through 9, as many times as you need digits, non-proportional spacing. Now print that out on overhead foil and cut them up.

Make a box with as many square cut-outs as there are digits. Or maybe one more if donations come in more generously than anticipated. An old but not too scratched file card box might do here. Place a light inside (mind its heat dissipation though!) and affix diffuse perspex or something similar behind the row of cut-outs so it disperses light, to create even illumination. Take a piece of wood strip, notch out one side, cut up in a miter box and glue around the cut-outs, in a way that the notched side faces inwards so people can slide in the numbers of the week. If this is for a church and it has a youth group: You've got helpers.

Regards, Joerg

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Reply to
Joerg

The display on eBay is cool as is, it would make a neat clock if I had any spare time.

The general consensus by those that aren't doing the work but feel the need to make demands is that it has to light up actively. This is after the ideas offered here were made. The simplest method I can come up with is to use the xmas lights as segments and power them individually by rocker switches. 24V should do the trick and if anyone complains about the brightness, well...

Thanks for the input.

Scott

snipped-for-privacy@yahoo.com wrote:

Reply to
ScottL

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