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State of Charge LED indicator

cjdelphi

Oct 26, 2011
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by reducing the input voltage?

the only pattern involved is the lights slowly turning on with voltage, if you want a chase pattern extra circuitry is required. ..
 

swu36

Jul 9, 2015
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by reducing the input voltage?

the only pattern involved is the lights slowly turning on with voltage, if you want a chase pattern extra circuitry is required. ..
Yeah, that's what I thought too...I see that LM3914 could serve the purpose, but am currently having trouble simulating the new circuit I drew - do you by any chance know any simulation software or online app that has this chip? Everycircuit doesn't...
 

cjdelphi

Oct 26, 2011
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the lm3914 is just one ic chip of thousands, it's difficult to find emulators packing all the ic chips!

and once you do find one...

A. does the chip support 40v+
B. does the chip support sinking/sourcing current capable of driving the LED? (If it does not, more circuitry required)

Welcome to the world of electronic Design....
 

swu36

Jul 9, 2015
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Ah, great...

As for the voltage limit, can I use a voltage divider or is that not a practical solution?
 

cjdelphi

Oct 26, 2011
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you could divide the voltage to make it usable with any chip/processor ..

eg a voltage divider reducing each step to a max if 5v (possibly with a zenner) feeding all those inputs into a shift register, then read each state of the led...

there's many ways, just make sure the input matches the voltage specs of the ic or you will see magic smoke :)
 

swu36

Jul 9, 2015
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Haha, would not like to see magic smoke...

I didn't understand the example though...could you elaborate a little bit more on it please?
 

cjdelphi

Oct 26, 2011
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The everycircuit one?

that's purely a voltage status, full battery all led's light, low battery only 1 or 2 LED's will light... i cloned the circuit you already had to show you how it worked...

i've not given you a chaser circuit...
 

swu36

Jul 9, 2015
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Yeah...
eg a voltage divider reducing each step to a max if 5v (possibly with a zenner) feeding all those inputs into a shift register, then read each state of the led...

I meant this part...
 

cjdelphi

Oct 26, 2011
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ah... just 2 resistors to make a voltage divider, a zener can be added to prevent it going over say 5v (depends on the ic...)
 

swu36

Jul 9, 2015
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Ok, so that solves the 48V -> 12V problem...now what is this other problem that I have?
B. does the chip support sinking/sourcing current capable of driving the LED? (If it does not, more circuitry required)

I mean, how do I find out what this current is?
 
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