Output at Inverting amplifier?

[tpj]

Refering to the circuit diagram attached, I applied an input ac signal of 200 Vrms, 50 Hz. The output received was dc -15 volts.

Can anyone explain this?

I was expecting output of 2 volts as the gain of the amplifier was set at 10 (=10Mohm/1Mohm).

Thank you!

-TPJ

 

[LvW]

Try to decrease both resistors by a factor of 10.

Added after 5 minutes: This will not help too much, because of the large time constant. Remove the capacitor, because you have a low pass with a corner frequency below 1 Hz !!

 

[FvM]

If the schematic is correct, there must be a DC offset at the said 200 mV input, otherwise the output would be 0V DC and about 0.6 mV AC. The resistors have rather high level, but the TL072 input current is in the pA range and can handle it.

As you apparently expected a different result, you should recalculate the amplifier dimensioning.

 

[Audioguru]

The output of a TL072 cannot go to -15V when it has a + and - 15V supply. Its max voltage is + and - 13.8V.

 

[Borber]

Because of 1uF feedback capacitor the circuit acts as LPF or integrator for 50Hz signal. First change capacitor to 10pF.