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Water Softener
3.7V to 5V
Solar Charger



Last update 27.11.11
The electronic water descaler is more effective device than powerful magnets placed around the incoming mains water pipe. This device operates by wrapping coil of wire around the incoming water mains to pass a magnetic field through the water. The theory is that it causes the calcium in the water to stay in solution and so inhibit it from adhering to pipes, taps, baths and kettles.
Reading many sources about the way it works I decided to try and make one. A few days after installing it I noticed a difference in the behaviour of the deposit of lime scale in the kettle and around the sink, it was much easier to remove the deposit, also the scale deposit was reduced to about half the amount.
Since it's unknown the true benefits of lime to our health and we also don't know the effect of the residual magnetic in the lime, it is recommended to use the descaler for washing water only.

There are 2 version for the circuit, both have similar characteristics. Select the one that will be easier for you to get the components.
Click Download Software to download circuit diagram.


Circuit 1 Description
See also Technical Tips

  • The +V is 8 to 10VDC. The current at 10V is 50mA. Any 9V universal power supply is powerful enough. Make sure the voltage does not exceeds 15V because it can damage the 555 timer IC.
  • The coil on the water pipe is made of 5 meter long insulated wire of 24 to 20 gage. The wire is turned around the copper or plastic water pipe (it can not be steel pipe) in a single layer. On a pipe of 20mm diameter it will form 55 turns. Since the wire is 5 meter long the number of turns will be different for different pipe diameter.
  • The circuit is a 12KHz oscillator with a coil of 470uH at the output to limit the current through the water pipe coil to 300mA peak.
  • 56K resistor and 1nF (1000pF) capacitor determent the frequency.
  • You can use equivalents for BC337 and BC327.
  • 555 timer has to be bipolar (555N) .
  • 470uH can be any type that can carry 300mA.
  • 1N4148, 680 ohm and LED are optional components to indicate output signal and coil are present.
  • All resistors are 1/4 watt, 5% .



Circuit 2 Description
See also Technical Tips

  • The +V is 8 to 10VDC. The current at 10V is 50mA. Any 9V universal power supply is powerful enough. Make sure the voltage does not exceeds 15V because it can damage the 4049B CMOS.
  • The coil on the water pipe is made of 5 meter long insulated wire of 24 to 20 gage. The wire is turned around the copper or plastic water pipe (it can not be steel pipe) in a single layer. On a pipe of 20mm diameter it will form 55 turns. Since the wire is 5 meter long the number of turns will be different for different pipe diameter.
  • The circuit is a 12KHz oscillator with a coil of 470uH at the output to limit the current through the water pipe coil to 300mA peak.
  • 33K resistor and 1000pF capacitor determent the frequency.
  • 4049B is a 4000 series CMOS. Any make is ok.
  • 47nF cap. and 1K resistor are noise suppression, they can be omitted.
  • You can use equivalents for BC337 and BC327.
  • 470uH can be any type that can carry 300mA.
  • 1N4148, 680 ohm and LED are optional components to indicate output signal and coil are present.
  • All resistors are 1/4 watt, 5% .

There are 2 third party sources of kits to buy on eBay:


Comments, ideas and life threats are welcomed.


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24.06.2014 - 09:26
Name: Ravinder Kumar
Comment: Dear sir Kit is now available at ebay as linked below http://www.ebay.com/itm/Electronic-Water-Descaler-Decalcifier-Limescale-Remover-DIY-KIT-student-project-/271520568678?pt=LH_DefaultDomain_0&hash=item3f37e31566 thanks and regards

13.06.2014 - 17:50
Name: Moty
Comment: Hi Suek. In most browsers you right click the image and select to save it. I attached a copy. The softener gives different results depending on the minerals in the hard water.

13.06.2014 - 08:55
Name: Suek
Comment: I\'m really interested in this as a project. Let me start by saying though that I cannot get the images of the circuit diagram to load properly is there anywhere else i can go to see them. Does this softener reduce the hardness of the water?

09.06.2014 - 03:07
Name: Moty
Comment: Hi Girish. The number of turns isn\'t critical. The current through the coil is dictated by the inductor on the PCB. The copper tube reduces the magnetic flux because the circuit sees it as a single turn coil. You will get stronger magnetic flux winding the coil on a plastic tube. There are many reports of researches of softeners on the web. You will find that the results of experiments are inconclusive and vary a lot depending on the minerals in the water. This leaves you with the option that you have already seen, to wait and see the results in your house. I\'ve never tested the kit from Thailand, looking at it made me convinced that it is exactly my circuit. The LED is on the output so if its lit it means that the output is on.

08.06.2014 - 10:48
Name: girish
Comment: Hi Moty Thanks for the instructions for novice DIY enthusiast explaining the science. I have ordered the kit from the supplier, however with a 22mm pipe I achieved more that 60 turns, will this affect the performance of the device. On the kit there is a LED to indicate power supply on, is there any thing else that needs to be noticed for the device to be working. Some of the comments are about frequency counter and oscillations, am I reading too much into it. Should I just wait and see if there is improvement in the water condition and scale formation. Thanks.

26.05.2014 - 14:11
Name: Moty
Comment: Hi Ravinder, Good luck with your business venture. If you wish I can put a link to your shop on my website.

25.05.2014 - 18:13
Name: Ravinder Kumar
Comment: I happy that designer of the kits wants to promote it for the benefit of society: I am collecting the full kit with essential hardware soon it will be available for public at no profit no loss basis enquiries are welcome at RK1049@gmail.com

25.05.2014 - 18:08
Name: Ravinder Kumar
Comment: the circuit option II is tested and tried and works well kit at no profit no loss will soon be available with us

12.02.2014 - 18:52
Name: Moty
Comment: Hi Gulabhai. Use the coil as shown on the project page. You may not get much effect of softening with 50 mm tube.

12.02.2014 - 11:35
Name: gulabhai
Comment: Hello, How do use this circuit with irrigation water 50mm pvc pipe?

28.01.2014 - 01:55
Name: Moty
Comment: Hi Tim. Thank you for noting that out. The eBay seller copied the description from my website, I also had a close look at the PCB, so itís very likely that they used my circuit. Of course everything on the site is totally free to use. Iím also pleased to fine that some more people will be able to DIY soften their water. I will add a link to this kit.

27.01.2014 - 19:19
Name: Tim
Comment: Good day. Is this kit the SAME as your design? THANKS :-) http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=281228582254&fromMakeTrack=true&ssPageName=VIP:watchlink:top:en

01.10.2013 - 11:41
Name: graindorge

24.09.2013 - 10:59
Name: Moty
Comment: Hi Dave. Thank you for the informative and helpful feedback. It is interesting to hear that the softener works well for kettles.

23.09.2013 - 20:33
Name: Dave Williams
Comment: very useful and easy to construct circuit worked first time and been running for month made a great difference to water kettles do no fur up anymore

23.01.2013 - 13:38
Name: Moty
Comment: Hi John It is good that your wife is helping with your research. To my experience the usefulness of the electronic softener is overrated. I recommend not to use the softener on drinking water, they say that it has no effect on human, I'm sure there is an effect that is only unknown. Sorry, since the coil is 470uH you have to increase it to 2.2mH. The coil behaves like a frequency dependent resistor to ac current. It's duty in this circuit is to limit the output current because the coil on the pipe is almost 0 ohm. You can boost the power with LM380, it will work more efficiently with the amplifier before the coil. There is a circuit on the net with two 555 timers generating sweep, try google for it. Have fun.

22.01.2013 - 07:54
Name: John
Comment: Hi Moty - Thanks for the quick reply. Amazingly enough I understand what you talking about. (Literally my first electronics project ever). The coil in the project is already 470uH so I assume it can just stay that way when adding the pot in. If I wanted to get the unit to automatically sweep a full frequency range multiple times a second - is that possible? I did finish building the original circuit (2) last night and had it running on a 1.5inch water pipe. The LED comes on and I hear a high pitched tone - so without a frequency counter can you use a compass or something to tell if its working? The water softening ability appears unchanged (limescale is still sticking like glue) however my wife thinks it made a difference to the shampoo in the shower (if its working correctly). Maybe I should add the LM380 amp after the 470uH coil to boost the power...

22.01.2013 - 07:19
Name: Moty
Comment: Hi John, The output current is determent by the coil in series to the coil on the pipe. If you decrease the frequency then the current will increase. The current limit is the ability of the transistors. The frequency can be changed by a pot and on the fly. f=1 / 2.2*R*C f in c/s, R in ohms and C in farads. If you replace the 33K for 50K pot in series to 4.7K you will be able to get the frequencies you want. To limit the current to 300mA change the coil from 100uH to 500uH.

21.01.2013 - 11:49
Name: John
Comment: Moty - Thank you for all your great free circuit designs. Superb. Re: Softer circuit 2 (4049b). I am completely new to electronics so I need the ABC explained. If I wanted to change the frequency of the circuit (33k and 1000pF cap) how would I change these exactly. One at a time? To what value? Could I adjust it on the fly with a variable resistor? How does the capacitor value change in relation to resistor (and if it was variable then what)? ABC Plaese - And finally what if I wanted the unit to create a sweeping frequency range like some commercial units do. Eg: "ScaleBlasters signal produces a unique square wave current that sweeps all the frequency responses from 2,000 - 24,000 Hz at a rate of 20 times a second." - Is this possible? If so would you have the ABC for that too? Thanks again!

29.08.2012 - 23:13
Name: Moty
Comment: Hi Jay. On 75mm pipe you will get about 15 turns. Keep the supply voltage the same. I can\'t predict how well it will work on high flow of water.

29.08.2012 - 09:51
Name: jay
Comment: for to 75mm di meter pipe how many turns are use &which ammount of voltage provide

02.07.2012 - 23:56
Name: Moty
Comment: Hi Ricardo, Yes there are other ways to construct an oscillator. Thank you for the suggestion. Moty

02.07.2012 - 14:56
Name: Ricardo Marinheiro
Comment: Just to leave a suggestion, that 555 are very cheap but if you have spare transistors and a few resistors and capacitors you can design an astable multivibrator, cheaper but no exact frequency. In any of the previous and this one too, if you wish to change the frequency of the device, just replace the 56k/33k with a 100k/50k trimmer(to allow ajustment) in series with 20k/10k(to limit max frewency), once these determine the charge cycle of the capacitor that provides the timming for the circuit (aprox. dt ~= 5C ). hope it helps :) with some new ideas

25.03.2012 - 12:58
Name: Nilesh
Comment: Hello, How do I use this circuit with Galvanized/Mild Steel Pipe? Regards, Nilesh

04.09.2011 - 20:12
Name: azeem ajmal
Comment: exclent

14.08.2011 - 19:59
Name: Moty
Comment: Hi Jim, Voltmeter or DMM set to DC voltage measuring at the base or emitter of any of the transistors, should read half the supply voltage +/- 20%. And if the transistors are warm as well then it means that you have output ac current.

13.08.2011 - 21:31
Name: Jim
Comment: Moty, I have completed this project and was wondering what is the output I should see with a meter or can I? Thanks

08.08.2011 - 03:00
Name: Jim
Comment: Hello Moty, Is it the 1 ohm or the 1 Kohm resister that is not required?

08.01.2011 - 18:22
Name: Moty
Comment: Hi Davie, The electronic softener does not reduce the amount of lime, it makes the lime less \'sticky\' hence easier to remove from surfaces. The softening is less effective on hot water. I wouldn\'t recommend to use it for drinking water because the effect of the magnetic residue in the water on our health is unknown.

08.01.2011 - 12:26
Name: Davie
Comment: Does this actually soften the water or just stop limescale buildup? Does it reduce the amount of lime in the water.

Name: rodolfo cabrera
Comment: Hello Moty, Im chemical enginner but i dont have much experience in electronic circuits. I see that the circuit can provide 12KHz. I read that that some brands offer 50 - 500 KHz. Have you test it with other ocsillator? How can i modify by a microphone the peak porwer (300 mA).there is a way to set the power cicle according the inner pipe noise? Can you provide a transformer circuit for this water softener? What is the value for the 1R resistor. If i want to attached the coil to a 4\" inches pipe what sould i consider? what modification should i do? thanks in advance. my e mail is:rodocabrera@hotmail.com

Name: Moty
Comment: Hi Rodolfo Thank you for your comment. It\'s good to have a chemical engineer onboard, probably you can help in making this black art of water softening more understandable or at least more believable. There are softeners in the market with permanent magnets (0 Hz) and also electronic softeners that use multiple frequencies that claim to work better, as you already said. I\'ve used 12KHz just because it was easy compromise. I tried my circuit at home for several months and it made a difference. I\'ve never tried any other softener, so I can\'t tell how good is my softener. It sounds like a good idea to set the output power by a microphone. Since my circuit consumes only about 0.6 Watt it is not important to add energy saving features to it. If you want to soften the water in a pipe of 100mm (4\") in diameter then you will need about 25 times the power (15 Watts), and in this case regulating the power by a microphone will give an advantage. 1R resistor is 1 ohm resistor. You can use any small power supply that comes on a mains plug and gives 6 to 9 VDC. In Europe they sell them in supermarkets, I guess they also do in Argentina. My guess is that the water flow in 100mm pipe will be too high for this circuit to be effective, you will need more intensive magnetic field. I\'m an electronics engineer so I can design a circuit for more power, but I don\'t have the means to try the effectiveness of it. If you wish to try this circuit use the same 5 metres long wire and wrap it around the 100mm pipe, you will get about 15 turns. Remember that the pipe can not be made of steel or other ferrous materials because it will block the magnetic field getting to the water. The calcium in the water is believed to be beneficial for our health. Also the magnetic residue in the calcium can stay for long periods of time and we don\'t know how it affects our health if we drink it. This are some of the reasons people don\'t feel happy magnetizing drinking water. This softeners are very useful for treating water used for washing. Good luck with your experiments. Don\'t hesitate to ask for more information if you need it, and if you learn something that can be a help for us, please add a comment.

Name: Hesam
Comment: Hello I designed one softener system, I\'ve not installed it yet. I have question, I injected the 220V voltage with only 1mA through the coil(winding on the pipe), I injected this voltage by transformer. is it enough for water softing? More current is better or voltage, here?

Name: Moty
Comment: Hi Hesam For having strong enough magnetic field you need at least 100mW on the coil. When the current through the coil is 1mA then the voltage on it has to be at least 100 volts. If the magnetic field is weaker then the softening is less efficient.

Name: Hesam
Comment: Moty, Thank you for your answer. I designed my circuit with microcontroller and I want to convert its 5V output voltage (contains frequence for softener) to higher voltage and current for injecting to pipe coil.in the other words, I need one voltage converter with enough current (500mA to 1A) for one big pipe. could you help me ?

Name: Moty
Comment: Hi Hesam One way can be to make a coil with resistance of 4 ohm on the water pipe. Connect the output of the microcontroller to the input of an audio amp and connect the coil in place of the speaker. The LM380 is very common IC to buy, and you can get a basic circuit from the data sheet. You can use other available audio amp. Don\'t hesitate to ask more questions.

Name: Hesam
Comment: Hi dear Moty, thank you for your kindly helps. you are great engineer. yes, I\'m agree with you about the Amplifier, but about the coil it is hard to make a pipe coil with 4 Ohm resistance, because we have to choose one thin wire and wraping this wire with regular order one the pipe is little difficult. I want to build a coil with ordinary wire, and with connecting the output of amplifier IC to coil with one matching ferrite core transformer, that it has 4 ohm impedance on its input for amplifier output, because of driving maximum energy to matching transformer from IC, this is the only solution based on my humble idea, Although I don\'t have this ferrite based transformer formulas. do you have any other idea for this purpose ?

Name: Moty
Comment: If you generate one frequency then you can use an inductor in series with the coil on the pipe, like I do in my circuit, otherwise you can use 4 ohm resistor instead. It means wasting about 1w on heat, which isn\'t a big waste.Then you can have an easy to wind coil on the pipe.

Name: Hesam
Comment: Hi Moty, I have one question, 1W power is enough for one 2 inch pipe? Do you know how much power does we need for every pipe ? (1 inch 2 inch and ....). Another, do you know any other way instead of resistor for my previous question ? (MCU generates variable frequences).

Name: Moty
Comment: Hi Hesam My knowledge of water softening is limited, it is not an established science yet. I know that most softener use about 0.5W for 1\" pipe. I assume that for 2\" pipe you will need 2W. If you find out more during your experiments, please write a comment and we can learn from your experience. For variable frequency output the only way I can think of is a resistor in series with the coil.

Name: Hesam
Comment: Hi Moty, I think ne matching transformer is better than a resistor, because on resistor although we have a same current but it will have voltage drop on coil, but with matching transformer you can transfer the power to other side, we will match the high impedance (4 or 8 ohm) to lower coil impedance (0.5 ohm or less). what\'s your idea ?

Name: Jacques
Comment: Good Morning I came across your site and built the Electronic Water Softner as per the diagram supplied. What is the purpose of the 1R resistor in front of the coil? I\'m busy testing at the moment on 2 water heaters for the past week and is really exited to see the results, will remove the elements tomorrow to to compare and see if there is a difference so far. I believe you\'ve installed this as well and tested. What is your honest opinion: Does it work efficiently? Looking forward to your reply. Regards, Jacques BrŁmmer Technical Foreman Al Maha Desert Resort & Spa Emirates Hotels and Resorts

Name: Hesam
Comment: Hi Moty I installed the system on pipe and I checked the water after 2 days. I check one sample of water on first tap of building that its not far from the coil. it placed in 5 meters aside of the main building pipe, therefore we can say that we checked the water exactly after coil because taps and pipes inside the building have previous scale that can influence the sample. Although I used more power (1W or more for 1-inch pipe), after I boiled the sample water, I can see white scale of the bottom of dish ! . I used matching ferrite transformer and varibale frequency between 800Hz to 15Khz. I checked the output of transformer with frequecny meter and Ampere meter with attached coil. it was OK. but I saw the conclusion that I mentioned above. Do you have any idea? should I change the circuit or check the water again later? Regards

Name: Hesam
Comment: Hi Moty I want to optimize the softener again by changing one part of its circuit. I understood that the amplifier doesn\'t have one amount of amplification for all frequencies, on the other word you may take the 2W amplification for 1KHz and maybe 0.5W amplification for 15KHz. I think this isn\'t \"best\" method for softening purpose, because we should inject all frequencies to water with maximum and same power. I think we can get better results if we could solve this problem. Do you know any other method for amplification ? Another point, did you open one of the commerical softeners box? we I see their boxes in their websites, I think they don\'t use amplifier for amplification because even commerical ones have little box and for one powerful amplifier, we should put one big transformer and big heatsink that take more space. by the way, I checked the hardness of treated water after system, in laboratory we couldn\'t see any improvement in water hardness, maybe this is correct, because the system only changes the shape of minerals.

Name: Moty
Comment: Hi Hesam I\'ve never looked inside a commercial softener and I don\'t know about other circuits. I suspect that even the best softener in the market is less effective than desired. It is also difficult for me to comment on your circuit without seeing it. I don\'t know what frequency is best for softening the water, hence I can\'t recommend a circuit which is better than what I already have on my website. If you will be successful in improving on my circuit and you wish to offer your circuit to other people then you are welcome. If you have any technical questions about my circuit I\'ll be happy to help.

Name: marcelo
Comment: Hi Moty, I would like to ask you if this circuit would help my condensate pump , i seems to creat a lot of calciun buit up so if I put thin in the intake what do you think ? Thanks

Name: Moty
Comment: Hi Marcelo If the condensate contains calcium that came from vapour of hard water then I guess the magnetic softener will help. It is only a guess because I\'ve never come across information about such application. Most condensate of vapour from the air contain dust, microbes and other contaminants.

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