i am not seeing a 1.2 rms voltage after the divider and before entering 1IN + . this happens when i plug the opamp in the circuit. while the opamp is not plugged in, the divider shows me the 1.2 rms voltageSo the input voltage is divided by 11 (R2/R3), then divided by 2 (R1/R5), then multiplied by 2 (R7/R6). Why would you expect it to be 1.2V rms?
thanks for reply. i said offset to describe the whole functionality of the circuit. i tried LT spice to verify the concept before implementing but it seems that it is a hardware issue. the problem happens when plugging the opamp in the circuit. other with i can see the division as it should be. the voltage source was from a transformer BV020 with 180 ohm on the outputhi Tarek,
This is what LTSpice shows for your circuit.
[ please check make sure I have read your circuit correctly].
When you say Offset, do you mean you want the Vout signal to swing above 0V .?
E
View attachment 248382
yes, this is true. mu fault i am using the second type with has output of 13.5 so i should have 1.2 rems voltage on the output. the issue i want to ask about is why plunging the opamp in the circuitry cause the voltage to drop after the divider from 1.2 to 0.5hi T,
With that 10k/1k voltage divider you will get 9Vrms * (1/11) = 0.818Vrms and that is what LTS shows, not 1.2Vrms as you have posted.
So, if the Vin is 9Vrms , swinging +/-Vrms about 0V, what signal do you want at Vout.?
Could you post a photo of your OPA layout, we can then check for any errors.
E
View attachment 248387
Hi,i want to ask about is why plunging the opamp in the circuitry cause the voltage to drop after the divider from 1.2 to 0.5