A little trouble with the LM311 comparator

[strongdrink]

Hello all,

I recently bought a couple of LM311N comparators.. only trouble is, I am a bit confused on what everything does.

To my knowledge...
pin 2 gets compared with pin 3
if pin 3 has a greater voltage pin 2, it will send the voltage of pin 2 to the output pin (7)
from pin 7, you can hook up an LED or something

I am not sure what the "balance" or the "balance strobe" pins do
Do I connect the Vcc and Ground, or Vcc and Vee?

Thanks for any help

 

[alexan_e]

LM311 compares the voltage of pin 2 and 3, when the negative input has a higher voltage then it grounds the output, when the positive input has a higher level it leaves the output floating because it is an open collector output (pin7).
You have to connect a pullup resistor to the output so that you get a positive voltage output (instead of floating).

The output level will be 0 or the pullup voltage, there is no middle value and the "it will send the voltage of pin 2 to the output pin (7)" does not apply

See the datasheet examples
**broken link removed**

Alex

 

[strongdrink]

What do the balance and balance strobe pins do?

 

[strongdrink]

Would you mind posting a very simple schematic for the LM311? Maybe pictures.. I tried building a small circuit using a pot resistor to turn on an LED with the comparator a couple of different ways and I didn't quite get it working..

---------- Post added at 23:05 ---------- Previous post was at 22:18 ----------

Ok, here is my schematic at the moment..
**broken link removed**

 

[alexan_e]

Take a look at **broken link removed**

You should connect the cathode of the led to the output and apply two different voltages to the inputs.
Invert your led.

 

[yura717]

Voltage Comparator Information And Circuits
Electronics 18
Comparator - Wikipedia, the free encyclopedia

 

[strongdrink]

@alexan_e sorry, the LED was the wrong way in the diagram (my circuit had the cathode connected to the output) and both the inputs are different voltages, ~5.1 and ~3.4 (tried swapping with no luck)
Could someone possibly re-draw my diagram please? =]

EDIT:
oh, this site may have answered my questions. just need to try it out
Electronics 18