Frequency detector

[ariakovo]

Hi ariakovo,

I understand how datasheets can be confusing, because other applications than the one you want may also be presented. In the case of the 567, go to its page 8.
You will see a circuit called AC test circuit and application information on the right side that gives the formula for calculating the frequency you need. In this case, it is:
1/(1.1*R1*C1)

I have attached a part of a schematic from a circuit I built with actual values. I don't recall at the moment what its frequency was. On that circuit, the components to adjust the frequency are labeled C4, R7, and R8. That is, the RC filter attached to pins CT and RT. YOu will need to calculate appropriate values for the frequency you decide to use. Good luck. John

Thanks for the tips.You said that there is a RC filter.Can i use the lm567 like a filter and like a demodulator?For example if i put one other frequency how will respond.If i can't it's ok.I understant how to calculate the frequency.Thanks

 

[jpanhalt]

It will respond only to the frequency to which it is tuned (don't forget it has a finite bandwidth). A sufficiently different frequency will not cause a change in its output state. In fact, its name "tone decoder" described that function. A series of 567s tuned to the different telephone tone frequencies could tell you which keys had been pressed. John

 

[ariakovo]

It will respond only to the frequency to which it is tuned (don't forget it has a finite bandwidth). A sufficiently different frequency will not cause a change in its output state. In fact, its name "tone decoder" described that function. A series of 567s tuned to the different telephone tone frequencies could tell you which keys had been pressed. John

Thanks a lot!!

 

[Papabravo]

The envelope detector is a good circuit to start with. It will detect the presence or absence of any signal over a wide bandwidth. To be more selective there needs to be something that responds to frequency. Googling "phase locked loop" will also result in numerous hits. Check out the number two hit
**broken link removed**

 

[kiewirevo]

hi there.
i want to make a similair proyect but i dont know how to start... i want to make an RF radar that detects certain frequencys like the ones from cellphones, wireless routers and wireless mouses.... reading through this forum a question popped up to me. how do you recieve de RF?, do you have an antenna or a specific circuit assigned to it... because i want to make an antenna (or circuit) that can vary through various frecuencies detecting diferent kinds of frecuencies... anybody can help me with that? it would be greatly apreciated .