Hello everyone,
Just got my new equipment lately, I was playing around with a simple TL972 opamp (See image : note R1 is 200 ohms, not 1K). So R1 +R2 is 10.2K and R3 +R4 is 14.7K which should give me a gain of 2.4411...
So if Vin is 900 mV, the scope should on CH1 2.197.... while CH2 should read 900 mV. As you can see on the screen caputre of the scope, this is quite close (CH1 = 2.2V and CH2 = 860-870 mV). Since I'm using 5% resistors, no surprise here.
What bugs me, are those spikes in the middle. What the...! I just don't quite get it. The circuit is powered has follow using Rigol's DP-832 PSU (3CH 30V-30V-5V). CH1 is set to 12V, which power the opamp. Opamp's V- is GND on CH1. CH3 is set to 900 mV which is my Vin. CH3's ground is connected to CH1's ground (it has to be connected somewhere, right?). The circuit is built on a standard solderless breadboard. I think its the culprit, but I'm not so sure.
Any ideas?
Thanks