I'm relatively new to electronics and recently purchased an LM324N quad op-amp to fool around with after learning about op-amps in my ciruits class. I built a simple non-inverting amplifier and after taking some measurments with a voltmeter I am quite confused. I connected pin 4 (VCC) to a 10.4 Volt power supply. I grounded pin 11 (GND). Before adding the feedback network (nothing else connected to any of the pins) I measured the voltage at pin 1 (output 1), pin 2 (input 1-), and pin 3 (input 1+). I expected them all to be 0. Instead, the voltage at pins 1,2,3 were all around 9.47 and the voltage at the GND pin was 9.88? I then set up the op-amp in a noninverting configuration (see my crappy drawing attached). After hooking up the feedback network and before I applied any input (just the feedback network) the voltage at pins 1 (output 1) dropped to 9 V. The Voltage at pin 2 (input 1-) dropped to 8.38 V. And the voltage at pin 3 (input 1+) dropped to 8.59 V. What is the reason for this voltage drop??? Then after connecting the input from the voltage divider (roughly 1 V open circuit) to pin 3 (input 1 +), the voltage at the that pin read 7.9 V and the output was 8.88 V. NOT A SINGLE READING MADE SENSE TO ME BASED ON WHAT I LEARNED AND ITS DRIVING ME CRAZY. I expected a gain of around 2 based on the feedback network (1+r1/r2). Seeing as how the input from the voltage divider circuit was around 1 volt, I expected to see 2 Volts at the output.
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