Hi
I am building a simple comparator circuit as a test ground for another project.
The comparator is LM311N.
The LED lights up when the V+ input is above 6.3 volts, but it doesn't go out until the V+ input goes down to around 0.5 volts....shouldn't it turn off as soon as V+ gets under 6.3 volts???
Confused...
I looked at datasheet examples and all, but can't really seem to figure out why it doesn't work as intended.
Pins 5 and 6 are tied together, and pin 4 (V-) I left unconnected, as the circuit wouldn't work at all with it connected to ground.
Also, the datasheet mentions it doesn't need a dual power supply, so what should I do with pin 4 (V-)



Thanks for any input!

 

Pin 4 is Vee should be connected to GND. Also put a 10K resistor from output of LM311 to the Battery positive. The LM311 output is open-collector.

Allen

 

Thanks Allen, that did the trick!