adsl filter with L.E.D indicator

[rnbguy]

Hi All,

I have a question, I am trying to build an adsl filter or passive device, which contains an L.E.D indicator if ADSL frequencies are detected on the line.

The device does not need to handshake or anything, just detect dsl frequencies (not just voltages)?

Am i asking for something from the future or is this possible given what we have today?

 

[Diver300]

I would say that it is possible. However you will need amplifiers and filters, and you will need to get the power for them from the telephone line voltage.

 

[dougy83]

maybe a simple charge-pump driving a fet (which controls the LED). The fet gate should have a capacitor and resistor such that the gate voltage slowly (dis)charges and the ADSL data signal is not affected. A charge-pump with suitably small pass capacitor will also filter out the low frequencies