Circuit : Andy Collinson
This simple circuit uses an oscillator to create a magnetic field around a water pipe. The idea goes back to a theory from 1930 which claims that a magnetic field
in water causes calcium carbonate crystals to clump together and form larger crystals. This reduces the chances of smaller deposits from clinging to the inside of pipes.
Does it work? I'm not sure but the circuit as inexpensive as possible.
Water Conditioning Theory
The idea of water conditioning is not new, and goes back to the 1930's. Hard water has a high concentration of minerals, the most abundant being the calcium particle.
For illustration only, imagine the white dots in the copper pipe are mineral deposits. The makeup of deposits leads to the term "Hard water" and reduces the effects
of soaps and detergents. Overtime these small deposits stick to the inside of pipes and can block filters, taps, shower heads and leave residue in kettles. Water can
be treated chemically, but this is expensive.
The illustration below shows two coils wound around a copper water pipe. I suggest leaving a gap of about 1 inch between the coils. The idea behind this circuit
is that a magnetic field around the pipe causes calcium particles to clump together. Copper wire with plastic or PVC insulation should be used and note that the coils
do not make electrical contact with the pipe.In doing so, larger particles are formed which pass through the pipe and do not cling to the inside. Does the idea work?
I'm not sure but the circuit is cheap enough.
A standard NE555 timer is used to form an astable oscillator. Its free running frequency is about 15kHz with component values shown. Power supply can be from 9 to 15 Volts,
the output voltage at Pin3 will swing to the full supply voltage. The diagram below shows a typical transient waveform in LTspice
The yellow numbers 1 and 2 are just the cursors, and reciprocal of the time difference indicates the frequency. Although no switch is shown current drain is about 5mA.
This is a little high for batteries so could be run from a small power supply. Please note, that in some countries
and here in the UK copper water pipes are often connected to the electrical earth, so make sure your coil leads do not make electrical contact with the pipe.