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Show the schematic.
Yeah i used an oscilloscope to look at the output at different frequencies this leads to another question i have.I tried to plot a graph of gain(dB) against frequency and we are given a graph to use as an indication however my graph turned out nothing like itJust to expand on what Mat has just said,
the minus sign indicates that the amplifier is inverting.
If you are using a sine wave to measure the gain rather than a DC signal, "reversing the leads" will not make much difference.
If you are using an oscilloscope to look at the input and output signal, you will see that they are out of phase with each other.
JimB
And...we are given a graph to use as an indication however my graph turned out nothing like it
At the following frequencies I got 1.93V for 1Hz,3Hz,10Hz,30Hz,100Hz,300Hz,1kHz,10kHz. and for 30kHz i got 1.85V 1.33V for 100kHz ,300kHz i got 560mV 60mV for 1MhzYeah i used an oscilloscope to look at the output at different frequencies this leads to another question i have.I tried to plot a graph of gain(dB) against frequency and we are given a graph to use as an indication however my graph turned out nothing like it
And...
What graph were you given as an example, and what did your results show?
JimB
posted nowYou could suspect that to discuss your graph it would be good to have it posted here.
One can only assume so.Also my lecturer told me to put a negative sign in front of the output figures i got even though they weren't negative on the oscilloscope is that because its an inverting amplifier?
Correct, you cannot have logs for a negative number.then it says to convert the calculated gains into decibels(dB) by using the following formula 20log(Av) but you cant log negative number so I am quite confused
AG, please read what the OP ACTUALLY wrote, it was VOLTAGE, not GAIN.But you show a gain of less than 2 at 1Hz and less gain at higher frequencies.
However, I have just plotted your data and it is fine, within certain limitations.
He wrote that the gain at 1Hz was 5.711146dB and his graph showed it. A voltage gain of 2 is 6dB so that is why I said his gain is less than 2.AG, please read what the OP ACTUALLY wrote, it was VOLTAGE, not GAIN.
Also consider the numbers presented before launching off into a tirade about solderless breadboards, deficient signal generators and shonky old 741 op-amps.
JimB
At the following frequencies I got 1.93V for 1Hz,3Hz,10Hz,30Hz,100Hz,300Hz,1kHz,10kHz. and for 30kHz i got 1.85V 1.33V for 100kHz ,300kHz i got 560mV 60mV for 1Mhz