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5 votes

Digital Signal Processing vs. Analog Signal Processing for 100kHz DAQ project

In two pictures (made using octave) a 1 kHz signal sampled at 1100 sps: and at 1200 sps: How could digital processing distinguish those from (respectively) 100 Hz and 200 Hz signals? Aliasing must ...
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4 votes

Digital Signal Processing vs. Analog Signal Processing for 100kHz DAQ project

ADCs usually need an anti-aliasing filter, otherwise frequencies above Fs/2 will alias to frequencies below Fs/2. For example if your sampling frequency is 48kHz and there is no anti-alias filter, a ...
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3 votes
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Making a voltage range filter (or a voltage bandpass filter)

this can't be done with just passive components -- you'll need some transistors and/or comparators. With comparators, set one up to detect if VIN > 1 V, the other if VIN < 2 V. Then AND the 2 ...
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3 votes
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Confusion In RC circuit

I can't say where you went wrong with your math but, in this simple example of an RC network, whenever the voltage source instantly rises to 5 volts from 0 volts or instantly falls to 0 volts from 5 ...
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3 votes
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Power supply overload protection work around

I need to switch on a contactor that uses around 3.2A inrush current for around 20ms... ...the power supply breaks down the output voltage around 3.1A ... at 3.1A, the output voltage of the power ...
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3 votes

Digital Signal Processing vs. Analog Signal Processing for 100kHz DAQ project

Do we really need an analog filter if the signal is to be converted to digital? First thing: you need an aliasing filter before the ADC. This may already be done on the DAQ board, so check that. As ...
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2 votes

Confusion In RC circuit

Were you to solve the differential equations for this circuit, you would find that the voltage across the capacitor always is predicted by this equation: \begin{align} V_C(t) &= V_\mathrm{f} + \...
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2 votes

Digital Signal Processing vs. Analog Signal Processing for 100kHz DAQ project

OVersampling with decimation helps to reduce the order of the "brick wall" filter for Nyquist aliasing noise to be rejected where the dynamic range and ratio of oversampling determine order ...
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1 vote

Electret microphone to speaker noise

Of course you have acoustical feedback howling. The mic can hear the speaker and causes sounds to go around and around. Out the speaker and into the mic, amplified then out the speaker and into the ...
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1 vote
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Help Understanding Opamp Topology (Infinite Gain Multiple feedback with Resistor to Gnd?)

Antonio shows that varying R14 can shift resonant frequency. Look closely, resonant bandwidth changes. As frequency drops with higher values of R14, Q is lower. If you want frequency to remain ...
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1 vote

Help Understanding Opamp Topology (Infinite Gain Multiple feedback with Resistor to Gnd?)

R14 (my R2) is very useful. Displace the center frequency "bandpass" filter. Updated info: One should see "analog filters handbook chapter8" from Analog Devices, page 8.76 fig 8....
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