Timeline for Help with analysing OP AMP circuit
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Aug 7, 2017 at 10:08 | comment | added | Dimitri | In your new simulation you simulate the resistor network without the shifitng voltage. If you add that part it will shift it to possitive voltages only. | |
| Aug 7, 2017 at 9:57 | comment | added | Dimitri | As I see it it's a simulation so I "-" of the SINE is the same as GND. If you don't add a GND to "-" it's the same as having a circuit with different returns. If you delete the GND from the circuit your generator doesn't have any return so that's the reason for having different results. | |
| Aug 4, 2017 at 13:45 | comment | added | Prithvi Raj Prakash | The output is across C1. I agree with the loading caused by R20, and one important thing i noticed is the amount of DC shift is assumed to be 2.5V, so i must remove the ground on the VSINE generator, and then you would see the voltage at the + input is exactly 2.4999V (notice how it is 2.21V here because of the ground i believe). Something i am seeing for the first time is that the feedback network is only a single resistor and not a divider(?). And any thoughts on point 4? | |
| Aug 3, 2017 at 13:04 | comment | added | Ian Bland | I might be being stupid here, but where is the output of the circuit meant to be? | |
| Aug 3, 2017 at 12:48 | comment | added | Dimitri | You are right about R20. I forgot about Ground and yes, R2 with R29 work as a divider. In this case the 2nd devider is R1, R21,R2. What I don't understand is why this distribution if it could be done much easier. | |
| Aug 3, 2017 at 12:29 | comment | added | Ian Bland | R20 is just loading the input, it's not reducing the voltage. R1, R21 and R2 are the potential divider which reduce the input to the op amp on which the gain resistor R3 operates. | |
| Aug 3, 2017 at 12:02 | history | answered | Dimitri | CC BY-SA 3.0 |