i am new to using comparators and have been trying a simple circuit to understand comparator. I have put the following circuit on a circuit board.
I have a 741 ic 8-pin version which i am using as comparator. I am using 6 volts from 4 AA size battries, with +vcc connected to pin 7, and -Vcc to pin 4. I have connected output pin 6 to +vcc with a 10k resistor. I am measuing the voltage between output and ground ( pin 6 and pin 4 respectively) using voltmeter.
I have shorted the inverting input pin-2 to ground (pin4)
when i measure output it shows 5.4 volts dc.
now i am giving a +3 volt to non-inverting input pin-3. positive lead of two aa size battery to pin -3 and negative lead to ground.
nothing happens.
Now in apply reverse voltage i.e. -3 volts to pin -3, still nothing happens and the output hardly changes by 0.1 or 0.2 volts.
am i going wrong somewhere.
I tried the same thing thing using LM-339 comparator still i get the same results.
I am basically trying to build a circuit which will tell me when a small voltage is generated.
I have a 741 ic 8-pin version which i am using as comparator. I am using 6 volts from 4 AA size battries, with +vcc connected to pin 7, and -Vcc to pin 4. I have connected output pin 6 to +vcc with a 10k resistor. I am measuing the voltage between output and ground ( pin 6 and pin 4 respectively) using voltmeter.
I have shorted the inverting input pin-2 to ground (pin4)
when i measure output it shows 5.4 volts dc.
now i am giving a +3 volt to non-inverting input pin-3. positive lead of two aa size battery to pin -3 and negative lead to ground.
nothing happens.
Now in apply reverse voltage i.e. -3 volts to pin -3, still nothing happens and the output hardly changes by 0.1 or 0.2 volts.
am i going wrong somewhere.
I tried the same thing thing using LM-339 comparator still i get the same results.
I am basically trying to build a circuit which will tell me when a small voltage is generated.