Im trying to configure my first (and basic) LM741 op amp inverter. My Vcc is +5V, my input is a 1.5v DC battery, the positive connected to the inverting input pin 2, and the negative connected to non-inverting input pin 3. Rf is 473k, Rin is 220k, so looking for a gain of about 2, and therefore looking for an output of about -3v, or thereabouts. But using my multimeter, +ve lead on output, -ve lead on V-, I measure +2.06V What am I doing wrong? Thanks in advance matthew
What am I doing wrong?
Top of the "reasons for not using the 741" list is the minimum supply voltage being nominally +/- 10V (although it will work down to +/- 5V without any guarantees). Running off a single 5 volt rail is rather a waste of time.
Next on the list is "Input voltage range is typically from -Vs + 2 volt to +Vs - 2 volt" so, even if you ran the 741 from a 20 volt supply, your 1.5 volt input would contravene #2.
looking for an output of about -3v, or thereabouts
7th on the list is "Typical output voltage swing is -Vs + 1 volt to +Vs - 1 volt" - this means the output is restricted to producing voltages that are within 1V above the negative rail and 1 volt below the positive rail so, if you are expecting an output of -3V you are going to be disappointed.
Listen, don't ever think of using this part - get some modern decent op-amps.