Chipped Water Purifier Cartridge

[p55xp]

Hi everyone,
This time I am seeking your support for an apprently new thing. I am using a drinking water purifier of a top brand in India.They use a chip on the filter cartridge set. This chip has no connectivity with flow of water (any type of rotating part) so that it can count the liters of water. I think it is counting flowing time. I opened the 'chip' and found one small pcb containing a diode, two capacitors, and an IC like something. This small pcb is connected with only two wires (+ and -), no signal of any kind. Four such chips (from four different cartridge) are connected to another small pcb where all '+' and '-' terminal are tied like parellely connected. And one pair of common '+' and '-' from this board connected to the microcontroller board, which controlls the whole management.
Now my question is "How this parallely connected pcbs count the volume of water used, or the time duration of flowing of water?"

Following is a magnified picture of this small pcb. Bigger capacitor is marked 105 i.e. 1uF. WW1 marked component is a schottky diode.

Thanking everyone, P55XP.

 

[KlausST]

Hi,

I can only guess:
maybe U1 is a "One wire EEPROM" like DS28EC20

Klaus

 

[p55xp]

Thanks a lot Klaus, it seems that you throw a light in proper direction. I don't know that in one wire protocol communication is accomplished over power line.
Thanks again,
P55XP

 

[BradtheRad]

Ways the circuit might measure:

* Pressure sensor. Water pressure drops when spigot is opened. Keep a running tally of occurrences and how much.

* Temperature sensor. Unit adopts room temperature during idle periods. Departs from that when water flows. Keep a running tally of occurrences, and how much.

* Make a component from a substance which dissolves in contact with water. Slowly in still water, faster in running water. Circuit detects when substance is gone, triggers an alert.