Utilizamos cookies en la web. Estas cookies son esenciales para que la web que funcione correctamente. Si sigue sin cambiar la configuración, vamos a suponer
que usted está dispuesto a recibir todas las cookies de este sitio web.
Para obtener más información acerca de las cookies, por favor haga clic aquí.
Low Pass Filters - Reduce Electrical Noise on an Analog Input Signal.
A low pass filter is placed on the signal wires between a signal and an A/D board. It stops frequencies greater
than the cut off frequency from entering the A/D board's analog or digital inputs.
The key term in a low pass filter circuit is CUT OFF FREQUENCY. The cut off frequency is the frequency above
which no variation of voltage with respect to time may enter the circuit. For example, if a low pass filter had a
cut off frequency of 30 Hz, the type of interference associated with line voltage (60Hz) would be filtered out but
a signal of 25 Hz would be allowed to pass.
Also, in a digital circuit, a low pass filter might be used to de-bounce an input from a momentary contact
button pushed by a person, or even a relay closure connected to a counter-timer input.
A low pass filter may be constructed from on resistor R and one capacitor C. The cut off frequency Fc is
determined according to the formula: