I need help with simple circuit ???!!!

[Amy 212]

I need help to do this circuit


- I need some help to designing circuit that accept 5Vpp input sinusoid of variable frequency. The input signal is assumed to originate from source with 50 Ohm impedance .

- The circuit to indicate when the input signal id < =5 KHz by turning off an LED when the input frequency Exceeds the specify value. In another words, The LED is to be on when frequency <= 5Khz ( +25%) or (-25%).

-Circuit to consist of only Resisters, Capacitor and LED.


Thanks a lot

 

[kchriste]

Google for highpass RC filter.