Cheap ADSL Filter dissected.

There are many CHEAPASS ADSL filters available in most of the electronics shops in india. Costs around Rs. 40/- each. The function of this filter is, to make sure that the ADSL Signals don't interfere with the Voice signals and vice versa. Here is a circuit That shows a standard ADSL filter.


And the one Which I bought, Has just 2 inductor coils, value unknown, Wish i had an inductance meter.

Here is how it is wired internally.


Wall o--- IND COIL ---o Phone
Wall o--- IND COIL ---o Phone

There are no capacitors used in this circuit at all. And this method will not give an ideal low pass filter. L2 and L4 are needed since we're dealing with the 'Tip' and 'Ring' of a phone line. So, while it is cheap, be carefull when you buy these filters.

Will add actual photos here soon.

Labels: ADSL, electronics, internet, lowpass filter, telephone