lm3919?

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goner19
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lm3919?

Post by goner19 » Thu Feb 11, 2010 10:47 pm

anyone have any idea what makes this thing tick?

it does not seem like a 100$ worth of anything

how hard would it be to make one of these?

is it just an lm3913?

http://cgi.ebay.com/ebaymotors/ws/eBayI ... 1840332496

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jwax
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Re: lm3919?

Post by jwax » Fri Feb 12, 2010 4:16 am

Link doesn't work.

SETEC_Astronomy
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Re: lm3919?

Post by SETEC_Astronomy » Fri Feb 12, 2010 8:19 am

I believe this is the proper link BMW Bar Voltmeter - eBay

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haklesup
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Re: lm3919?

Post by haklesup » Fri Feb 12, 2010 9:47 am

The price accounts for an exact fit in an upscale car. It is not a reflection of the cost of goods.

Couldn't find a datasheet for lm3913 but you're probably right

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CeaSaR
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Re: lm3919?

Post by CeaSaR » Fri Feb 12, 2010 10:44 am

The only reference I was able to find for the LM3919 was a dutch forum (english translation) where the poster listed
the LM "3914/3915/3919" (third post from bottom) for use. I looked up the datasheets for both the '3914 and '3915,
but the '3919 is nowhere to be found. It should be relatively similar, I would think, being so close in series number.

CeaSaR
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goner19
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Re: lm3919?

Post by goner19 » Sat Feb 13, 2010 1:33 am

im sorry the cocktails must have kicked in but the end of my post...lol

i typed lm3919 the lm3913 but the end of the post ...
sorry if that caused confusion.....

i meant lm3914n-1

but id like to figure out how it works with the alternator signal...
i built a bar graph circuit using the 3914 and it worked fine...

i was wondering if this was the similar application...and maybe i could link it to the 02 sensor that works off of a ground signal to build a air fuel mixture monitor...

has anyone out there done anything like this before?

thanks and sorry... =/

goner19
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Re: lm3919?

Post by goner19 » Sat Feb 13, 2010 1:38 am

Posted: Sat Feb 13, 2010 1:33 am Reply with quote

im sorry the cocktails must have kicked in but the end of my post...lol

i typed lm3919 the lm3913 but the end of the post ...


what kind of gammar is that? omg.....

im meant "by the end of my post"
thats it im going to bed =)

thanks again guys for putting up with me...=)

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MrAl
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Re: lm3919?

Post by MrAl » Sat Feb 13, 2010 4:22 am

Hi,


Do you have a schematic for how it is hooked up? We can take a look at it.
LEDs vs Bulbs, LEDs are winning.

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CeaSaR
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Re: lm3919?

Post by CeaSaR » Sat Feb 13, 2010 7:54 am

If you have the September 2009 issue of Nuts-n-Volts, look at page 95 for a schematic of the LM3914
provided by the board's own sghioto. As he explains, it is the standard schematic on the datasheet,
but only slightly modified to fit the criteria of the poster on that page. Do you still need a link to the
datasheet? Try here.This is for the LM3914, National doesn't list the variant you gave.

CeaSaR
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k7elp60
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Re: lm3919?

Post by k7elp60 » Sat Feb 13, 2010 1:06 pm

I have 1982 National data book. It lists the LM3909 and LM3914 thru LM3916 but no 3919, it does list a LM3999, which is a precision Reference. So no help here.

goner19
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Re: lm3919?

Post by goner19 » Sat Feb 13, 2010 8:42 pm

wow ceasar and setec you guys nailed it right on the head

ceasar i built one of the circuits in that data sheet.
it was pretty straigt forward....

setec nailed it for me thats exactly the application i was looking for
i have to spend some more time looking over but i sure want to make one for my car!

i love this site !!!
i always get the help i need !!!
thanks ton guys!!!

i just bought these on ebay...

http://cgi.ebay.com/10-LED-Bargraph-dis ... 8254087261

goner19
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Re: lm3919?

Post by goner19 » Mon Feb 15, 2010 9:07 pm

so i built both the circuit on the data sheet and the one sugested by setec...but have the same problem...

all on or nothing....
im not sure i giving it the right signal...

i tried hooking pin 5 which is the signal pin to a 10k pot
but same result ....when pin 5 hits ground all the leds go on
there is not incremental cascade of leds...

any suggestions?

thanks in advance!

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dacflyer
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Re: lm3919?

Post by dacflyer » Wed Feb 17, 2010 4:19 am

whats the voltage of your input signal ?
whats the result if you turn it on and no input signal ? or short the input to ground.
if you turn it on and the do not light up.,then its a good chance that your input might be out of range..

goner19
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Re: lm3919?

Post by goner19 » Wed Feb 17, 2010 5:17 pm

well thats just it
i dont have the signal(pin5) hooked to any thing
when pin5 is open all leds are on
when i ground it they go out

i have the whole thing running on 5v

i saw the trouble shooting section in the link posted by setec
ill see if i can figure it out
but there really is not much to it i dont know why its giving me touble

something tells me its pin6 and 7 relationship

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