Low Pass Filter Example No1

Leikrod

Joined Oct 10, 2017
16
A Low Pass Filter circuit consisting of a resistor of 4k7Ω in series with a capacitor of 47nF i,s connected across a 10v sinusoidal supply. Calculate the output voltage ( VOUT ) at a frequency of 100Hz and again at frequency of 10,000Hz or 10kHz.

https://www.electronics-tutorials.ws/filter/filter_2.html

I'm confused when they talk about the 10v sinusoidal supply.
20Vpp?
5Vpp?
Vrms?

ericgibbs

Joined Jan 29, 2010
11,095
hi,
I always assume if the value stated is 10V sinusoidal it is 10v rms

eg: UK mains supply 230Vac 50Hz is RMS
E

Ian0

Joined Aug 7, 2020
726
Doesn't matter. If the input was rms, your calculated output will be rms. If the input is peak-to-peak, then your calculated output will be peak-to-peak.

Leikrod

Joined Oct 10, 2017
16
Doesn't matter. If the input was rms, your calculated output will be rms. If the input is peak-to-peak, then your calculated output will be peak-to-peak.
I'm building the circuit on an app, and I cant seem to get the calculated value to match with the measure.

crutschow

Joined Mar 14, 2008
25,641
I'm building the circuit on an app, and I cant seem to get the calculated value to match with the measure.
How are you measuring the voltage?
Generally a standard multimeter will not measure accurately above a few hundred Hz.

Ramussons

Joined May 3, 2013
889
How are you measuring the voltage?
Generally a standard multimeter will not measure accurately above a few hundred Hz.
What if the same multimeter is used to measure the Input and Output of the filter ?

Ian0

Joined Aug 7, 2020
726
Depends on the frequency content of the waveform.