Dear Sir,

i need your support for this op amp circuit. Please refer image attached. I have used dual supply +-5V, IC used LM324SN.

i am suffering with output not getting as per simulation.

circuit has three section. first is wein bridge oscillator. second section is buffer amplifier (1K resistor used in feedback to limit current) and third is inverting amplifier.
when i connect resistor 465E in inverting amp circuit, output after buffer amplifier gets zero and when i remove this resistor i get 300mv.
i am not able to identify the reason. need your support.

 

hi Ravi,
The non inverting Input of the OPA of a real circuit requires a current path to 0V.
That is why the OPA 'works' when you connect a resistor from +In to 0V.
E

 

In general, both inputs of an opamp require a DC (resistive) path to ground for proper operation.

 

thanks for your support. Its now working.