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LD current bar display

naplam

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I think we can talk about this in a separate thread here.
So, this is my circuit to display the current going through the laser diode in a 10-segment bar display:



The circuit above is the display circuit and the circuit below is a current regulator circuit. By setting up the LM3914 to measure voltage in A in a range between B and B+1.25V we can measure the voltage difference between A and B in a 1.25V scale, which is a 0.25A scale assuming a 5ohm resistor between A and B. So every segment of the bar display is a 25mA step in the 0-250mA scale.
 



o_DEATH_ANG3L_o

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Pretty creative there. I like it. This would be good for a home based laser that would stay in the shop or whatever. :)
 

philguy

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Heck, I'd even put that into a not-so-much portable laser, to drag along! Cool idea, saves you the DMM to drag along!!!
 
H

High_Octane

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LarryQ said:
Kinda neat!!!!!

WHere can one find that IC??


LarryQ
Heres some info from the original Thread.
Good Idea to move it here to keep the original thread on topic.

Well I found that O2 Meter in my tool box in the garage.
Here are a few pics of it and its circuit. Guess I have another container for a box style laser :)






Here is what the chip has printed on it JB112AF & [highlight]LM3914N-1[/highlight]
Heres a link to the Data Sheet http://pdf1.alldatasheet.com/datasheet-pdf/view/8900/NSC/LM3914N-1.html
And where to get it http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=LM3914N-1-ND

For the LED BAR, The Part# [highlight]1001HDA[/highlight]
And where to get it
http://www.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=LM3914N-1-ND

The LED Part# above is for a LED with 10 RED bars, I have another one that is similar, However it has 7 green and 3 red bars. I like it much better. A similar one with 6 green and 4 red can be purchased Here http://www.gatewayelex.com/led.htm

I would like to fine one of these for sale somewhere!

http://news.thomasnet.com/fullstory/7513/589


I'm sure with the proper resister, this circuit could be modified to work the the voltages that DDLs driver uses.
10 Segment red LED bar graph display- 20-pin DIP 20mA, 2VDC per element.

I'll post more information as I progress.
 

Things

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nice work, and very creative! this would be perfect for a labby style laser too! ;)
 

naplam

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LarryQ said:
Kinda neat!!!!!
WHere can one find that IC??
I found it in my usual electronics shop, but you can also buy it online from several providers (check www.findchips.com for example). I wasn't able to find the bar display in a shop though... I'm using several leds for the time being.
 
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SenKat

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awe, MAN ! ANother idea taken, due to shipping times from overseas ! LOL !! I was talking to Merl and Tallaxo about this very thing on a labby :p Except - I was cheating, I opted for the ready made digi-display showing the amperage, rather than a bar graph :) I will post pics once it all arrives !!
 

o_DEATH_ANG3L_o

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That is awesome looking. Post some pics of it working. That looks like a radioshack project box, would be a nice little laser. Good Work man!! ;D
 
H

High_Octane

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Death Angel said:
That is awesome looking. Post some pics of it working. That looks like a radioshack project box, would be a nice little laser. Good Work man!! ;D
Thanks, It is a RS project box ;). The chip must have gotten damaged at some time ::), I have a few on order.
I'll post some pics when I get it setup on the bread board, then move it to the project box.
 




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