My first simple mains conditioner/surge protection:

[maxlorenz]

Hello everybody:
This is my first post starting a thread
Please dear Moderator, look at this, in order to avoid doing harm to anyone who attempts to build it (including myself).

This is not an original schematic but an adaptation of various ones. I'm not inventing the wheel, I know, but I wanted to post it because it is simple, cheap and it works, IMHO.

An externally hosted image should be here but it was not working when we last tested it.

Parts:

VDR: RS catalog nº 289 7301; use as many as you want. I use 3.

Capacitor X1: 47nF; RS cat nº 240 5334.

Capacitor Y2: 1.0nF; RS cat nº 441 9824.

Double apperture ferrite: 10uH each; RS cat nº 212 0617. I use at least 5 of these.

My AC mains are 220VAC. You should look at adequate parts if your AC mains are different.


Rather easy to build. Now I use them to power my digital front end(s) and my Class A power amps. I do find a positive effect in term of less HF noise but more importantly music is "rounder", less aggressive, with warmer tone and sweeter highs. I don't find any dynamics limitations.

Price, including cords and ac outlet should be around 20-30 UKP, depending on other parts quality.

I hope the diagram shows up

Please be kind with your comments as I'm very sensitive these days...

I hope you like it

Regards
Mauricio

 

[maxlorenz]

Oops!

The diagram doesn't show up.
Moderator: may I send it to you for edition?

Thanks
Mauricio

 

[maxlorenz]

I'm no good at this

The image is hidden on my gmail and a password is needed

Is there a charitative soul that would post it for me if I send it?

(seems that Moderator didn't like my post)

Thanks.
Mauricio

 

[wintermute]

Hi Mauricio,

if the image is no bigger than 100K and less than 900 pixels wide you should be able to upload it using the attach file bit below the input window.

when you have your image open in gmail right click on it (I'm assuming windows, not mac) and choose save image as. save it somewhere on your hard disk (or desktop) then use the browse button next to attach image to upload it

Hope that works for you.

and BTW welcome to the forum

Tony.

 

[Vidalgo]

Or use this fast and free service for image posting.

 

[Tyimo]

Hi Mauricio!

Please don't give up to post the picture! You make me interested for this mains conditioner.

Greets:

Tyimo

 

[maxlorenz]

Hi all!
Thanks for the help!

I hope you won't be dissapointed with this very basic unit
First image is of course the schematic. Second one is how it should look when built (rapid in-job drawing )
The double apperture core ferrite is made of a hi L material and also won't limit I.

An externally hosted image should be here but it was not working when we last tested it.

Thanks Vidalgo for the imageshack service. I hope I can post it.
My 10 year old daughter has a personal photolog and his daddy can't post a simple pick on the forum!
Our age is passed

and BTW welcome to the forum

Hi Wintermute, in fact I'm here two years. Only recently I found the "introductions" forum. I will make my formal intro ASAP

Thanks again and enjoy my first humble contribution


Mauricio

 

[ctviggen]

Are those capacitors really nanofarads? (i.e., 0.047 microfarads) Are those Radio Shack numbers? I can't find them in the US version of the catalog.

 

[claudio]

Should be RS-Components code: www.rs-components.com

Mauricio, why don't you get a ready to use IEC filter like RS FN9222-1/06 or similars?

Regards,
Claudio

 

[Tweeker]

Those are really nF, I see ~22nF capacitors to ground and/or across the mains on the primary side of alot of products. If you make them way too big they will eat some power and become less effective at HF.

 

[maxlorenz]

Hi

Should be RS-Components code: www.rs-components.com

Sorry, I forgot this "RS" could be confounded with Radio Shack It's RS-Components, of course.

Those are really nF, I see ~22nF capacitors to ground and/or across the mains on the primary side of alot of products. If you make them way too big they will eat some power and become less effective at HF.

Cx1 could be 47 to 100nF.
Cy2 could be 1 to 10 nF.
There's only one of each, as you see. How did I obtained these numbers? Easy, I looked what kind of caps used the "pro" conditioners. Not very elegant as explanation, but... hey, I'm only an amateur

Mauricio, why don't you get a ready to use IEC filter like RS FN9222-1/06 or similars?

And the fun of it???
Appart, did you see my double apperture core ferrite? This must be doing something good on both kinds of AC noise.

My trouble with posting the first post attempts to the understanding of the conditioner, perhaps.
May Moderator delete my "useless" posts (safe the first one! ) and transport the image to #1?... if this can be done...

Regards
Mauricio

 

[ctviggen]

Thanks, I bookmarked that page.

 

[peranders]

Price, including cords and ac outlet should be around 20-30 UKP, depending on other parts quality.

Just wondering why you don't buy a ready made filter? Cheaper and with better performance and probably more safe.

In order to get good attenuation the ground connection must be short and also with short leads of the caps which you hardly won't get here. 40, 20, 10 or 5 mm makes a huge difference in performance above 1 MHz.

In Sweden max 4.7nF is allowed as Y cap.

 

[karma]

hmm would it hold up to 30 amps at 220volts? or would it get $

 

[Mike Gergen]

All
Please be careful when doing something like this. The reason for the 4.7 nano limit as PA mentioned is because of leakage current between H and E.

MOVs are great for knocking down spikes. But, they are also great at going up in flames if the spike or surge is larger than it can handle.

Use caution!
Mike

 

[AndrewT]

Hi,
have you any idea why the 4n7F cap H to E limit is so low?

Can I assume that H to E is the same as Live to Earth?

I thought you could go to about 90nF (on 230/240Vac) and stay just below the 7.5mA leakage current allowed in a 30mA RCD (RCBO).

MOVs are great for knocking down spikes. But, they are also great at going up in flames

Does this mean MOVs fail as a short or that you simply have to replace them after they have been overloaded?

Comments from all are welcome.

 

[maxlorenz]

I see some interest

Peranders:

Just wondering why you don't buy a ready made filter? Cheaper and with better performance and probably more safe.

I already answered that. Appart I think the fewer parts, the better. Also, the inductor is made of N30 material wich start to work at "low frequencies" as stated by Epcos and doesn't limit the current. Now I can't find the quote

In order to get good attenuation the ground connection must be short and also with short leads of the caps which you hardly won't get here. 40, 20, 10 or 5 mm makes a huge difference in performance above 1 MHz.

Cap's leads can be made very short here fortunatelly caps width equals "channel" separation on the "crimp connector" (I don't know its exact name). Please refer to the 2º diagram (leads are exagerated)

hmm would it hold up to 30 amps at 220volts? or would it get $

Current is limited by apperture diameter of the inductor core: 3.4mm for wire and insulator More or less 2.5mm copper wire
As I said, I have Class A amps (Mosfet, 100W/8ohm) and I can't detect limited dynamics.

MOVs are great for knocking down spikes. But, they are also great at going up in flames

These are rated at 140 Joule energy absortion. You can put as much as you want. I fear MOV failure without external signs, from repeated insults

OK guys, thanks for the interest. I didn't want to extend on "audiophile" description of supposed sound improvement. This usually is not welcome at DIYaudio
Maybe someone would try it and see (hear)

Ah! and wait until I find a suitable "isolation transformer" to put in series with my baby

Enjoy!
Mauricio

 

[pmkap]

Mauricio,

I like your version of the Gatekeeper very much. The use of 'binocular' cores, rather than beads held together allow better coupling and functioning as a common mode choke. Additionally, it allows one to experiment with cores having different characteristics.
As to those who question why you don't use some XYZ filter, I'd think they haven't done sufficient empirical work to realize that different X caps, (and other components) can have a radically different subjective effects... (are we allowed to say such things on this board?)

 

[sam9]

I gather you are using the ferrites in place of inductors. TRhis may be a reason for DIY vs. buying one ready made. Some ready made ones that use inductors mage an audible noise ("Twannnng") when powered up and sometimes the nise persists as a hum. Depends on ghow "cleanm" the AC is to start with -- a true irony since if it were clean wyou wouldn't need the conditioner.

 

[Mike Gergen]

Each country is different for leakage so the max cap value may be different.

MOVs do fail as a short. When they do they go up in flames. 140 Joules should be plenty big. My concern was someone using a 20-40 Joule device. They aren't big enough. In a former life I worked for a company making power outlet strips with this type of surge protection. We used to place a fuse in series with the MOV. The fuse would blow before the MOV. I can't say why this was done but I will say it was "ugly"