How to use LM358N comparator ?

[shan.jey1]

Comparator LM358N

I am using lm358N comparator to compare input signal and the output is the corresponding led depends on the input.

My inputs are varies from 2 -12 volt, they are common inputs.

Ho can I do this?

Thanks for you help

 

[srizbf]

Re: Comparator LM358N

is it like for every volt you have an led to be lit.
i/p:2v-one led,
3v-another led ...

srizbf
17thmay2010

 

[IanP]

Re: Comparator LM358N

It looks like you are tying to build a voltge indicator with some opamps and LEDs ..
Have a look at the attached circuit - details at:

http://ecelab.com/circuit-simple-led-voltmeter.htm

IanP

 

[shan.jey1]

Re: Comparator LM358N

is it like for every volt you have an led to be lit.
i/p:2v-one led,
3v-another led ...

srizbf
17thmay2010

yes you are right.

Added after 4 minutes:

is it like for every volt you have an led to be lit.
i/p:2v-one led,
3v-another led ...

srizbf
17thmay2010

yes you are right.

Different input in different time, Only one output led to lit depends on the input.
Thanks

Added after 4 minutes:

It looks like you are tying to build a voltge indicator with some opamps and LEDs ..
Have a look at the attached circuit - details at:

http://ecelab.com/circuit-simple-led-voltmeter.htm

IanP

Thanks, Basically I need to build a function box to test switch module. It has up to 8 functions. depends on the switch function only corresponding led need to be on.

Thanks for the support.

 

[IanP]

Basically I need to build a function box to test switch module. It has up to 8 functions. depends on the switch function only corresponding led need to be on.

In which case you may consider changing the concept of the whole thing and employ a microcontroller, instead of trying to add some logic to simple comparator(s) ..
Microcontroller such as PICAXE (eg. PICAXE-20: The 20 pin version provides 8 outputs and 8 inputs, 4 of the inputs have analogue capabilities) are programmable in the simplest dialect of BASIC (or just flowchart), have A/D converters build in and easily can drive LED directly from pins ..

All what you need (software, manual, example etc. etc.) can be obtained for free from:
**broken link removed**


IanP

 

[srizbf]

if you use lm358 atleast >10 comparators (3 ics of quad comparators) are reqd .

instead i suggest you to check whether lm3914 from national semiconductor will suit you .

it is one ic with 10 comparators inside and with stable ref etc .
your final design may end with one ic itself.
it has on chip led driving for 10 leds.

3914 was meant for such applications .

but please check the datasheet before you start using.

srizbf
18thmay2010