LM3914 resistor values for 4.2V to 3V Li-Ion battery

bertus

Joined Apr 5, 2008
20,650
Hello,

Did you connect all points with V+ together to the + of the battery.
Also all points with a ground symbol must be connected together to the - of the battery.

Bertus
 

Thread Starter

gauravkothari23

Joined Nov 13, 2015
14
yes i have done so..... tried doing it twice.... but the result in improper....
i have 2 battries... one is 3.95v and other is 2.70v....
both shows the same status.....
 

Dodgydave

Joined Jun 22, 2012
9,306
yes i have done so..... tried doing it twice.... but the result in improper....
i have 2 battries... one is 3.95v and other is 2.70v....
both shows the same status.....
Do you mean 2 " Batteries" and the result "is" improper, think you need to go back to school...

If you bothered to read the datasheet, you would know how the chip works and be able to set the upper and lower limits..
 

Thread Starter

gauravkothari23

Joined Nov 13, 2015
14
yes two battries.... i think you have not read my post properly....
i dont connect my both the battries together.... i connect my 3.90v battery and set the upper limit and attach the load to it untill and unless the battery does not reach 3.10v and then to cross check it i remove the load and also the battery and then attach the other 3.10v battery.
so it would be better if you stop finding faults in me just to underestimate rather than giving me ideas... if it is soo.... you better stay out of it...
 

eetech00

Joined Jun 8, 2013
1,969
Hi

Try this one. You'll need a voltmeter to adjust it.
Set P1 and P2 to middle of range.
Set supply to 4.2 volts. Adjust P1 so all leds just turn on..
Set supply to 3.0 volts. Adjust P2 so all leds just turn off.

that's it.

eT
 

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Good night. First please excuse raising an old topic.

Reading this topic I saw that the battery being tested is at the same time the one that powers the LM3914. However I would like to power the IC, through pin 3, with fixed 5v, until the test routine does not use the battery charge.

My doubts are: in this case, the scheme below would be right? Would it be fair to keep the values of resistors, capacitors and trimpots? As for the LEDs, would not they glow too much? Would there be a way to regulate their brilliance through a trimpot? Lastly, would it be okay to connect the negative of the battery to the negative of the 5v source?
 

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Wendy

Joined Mar 24, 2008
22,155
Please don't post to long dead threads(called necroposting) I have approved your post this time but future necroposts by you will simply be deleted.

It is far better to start a new thread and if appropriate, post a link to this thread in your post. If you need help in navigating this forum software just type @Wendy in your post with your question and I will be tagged to come view it.
 

eetech00

Joined Jun 8, 2013
1,969
Good night. First please excuse raising an old topic.

Reading this topic I saw that the battery being tested is at the same time the one that powers the LM3914. However I would like to power the IC, through pin 3, with fixed 5v, until the test routine does not use the battery charge.

My doubts are: in this case, the scheme below would be right? Would it be fair to keep the values of resistors, capacitors and trimpots? As for the LEDs, would not they glow too much? Would there be a way to regulate their brilliance through a trimpot? Lastly, would it be okay to connect the negative of the battery to the negative of the 5v source?
Hi

I'm sorry...but I don't understand what you are asking.

You want to power this circuit with a fixed 5v supply.
What type of voltage source will you monitor?
What voltage range did you want to monitor?

eT
 
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