Huminator not huminating

DavenPaget · November 28, 2011, 07:38:05 PM

Quote from: chromesphere on November 28, 2011, 07:35:33 PM
Oh right, i though you could use any wire...no problem will do

You could , but rolling your own coils with normal wires just ... doesn't cut it .

DavenPaget · November 28, 2011, 07:39:39 PM

Quote from: chromesphere on November 28, 2011, 07:35:33 PM
Oh right, i though you could use any wire...no problem will do

You could roll your own coils but using normal wire just doesn't ... cut it .

edvard · November 28, 2011, 09:18:32 PM

For my breadboard supply (which is crap), I just tacked an extra rectifier+filter stage on the side, cleared up everything.

My power supply was simply awful, no amount of caps would work.
In my pea-brain I hit upon the conclusion that it was SO noisy, it was still pumping out AC; so I rectified it.

Voilà!

chromesphere · November 28, 2011, 09:25:00 PM

Sounds the same as my problem!!

Excuse my electronic noobrotosity here Edvard, but how do i do this (rectify the output voltage)? Do you have a link to a circuit i could follow?

Edit: Oh i think i just remember...im sure i feel asleep in the rectifier class...its 4 diodes in a sort of diamond shape?

DavenPaget · November 28, 2011, 09:54:02 PM

Quote from: chromesphere on November 28, 2011, 09:25:00 PM
Sounds the same as my problem!!

Excuse my electronic noobrotosity here Edvard, but how do i do this (rectify the output voltage)? Do you have a link to a circuit i could follow?

Edit: Oh i think i just remember...im sure i feel asleep in the rectifier class...its 4 diodes in a sort of diamond shape?

I'll draw up a schem for you .
EDIT:

chromesphere · November 28, 2011, 10:14:06 PM

Cheers Dave!
Heres a noob question, would rectifing the output drop the output voltage below 9v?

DavenPaget · November 28, 2011, 10:15:08 PM

Quote from: chromesphere on November 28, 2011, 10:14:06 PM
Cheers Dave!
Heres a noob question, would rectifing the output drop the output voltage below 9v?

Sure will , have you checked your wallwart's voltage unloaded ?

chromesphere · November 28, 2011, 10:17:47 PM

Ill have to check it tonight, i think it was 9v's though. I might just try to rectify it anyway and see what the resulting output voltage is.

edvard · November 30, 2011, 11:46:55 AM

Nice one, Dave!
The one on my breadboard is a proper 4-diodes-in-a-diamond configuration, followed by a electro-cap to ground, 100-ohm resistor, then another cap to ground.
I'll have to try yours, seems much simpler...

QuoteHeres a noob question, would rectifing the output drop the output voltage below 9v?

Because most any wall transformer is going to put out a bit more than 9 volts (unless it's well-regulated, in which case, if it were, you wouldn't have this problem...), the diode drop is negligible.

Here's my circuit:

EDIT: Figured out how to embed images from the Gallery.

DavenPaget · November 30, 2011, 12:20:11 PM

Quote from: edvard on November 30, 2011, 11:46:55 AM
Nice one, Dave!
The one on my breadboard is a proper 4-diodes-in-a-diamond configuration, followed by a electro-cap to ground, 100-ohm resistor, then another cap to ground.
I'll have to try yours, seems much simpler...

QuoteHeres a noob question, would rectifing the output drop the output voltage below 9v?

Because most any wall transformer is going to put out a bit more than 9 volts (unless it's well-regulated, in which case, if it were, you wouldn't have this problem...), the diode drop is negligible.

Here's my circuit:

Aargh, forgot how to embed images from the gallery...
http://www.aronnelson.com/gallery/main.php/v/edvard/power.gif.html?g2_imageViewsIndex=1

That's ... Full bridge , overkill and unnecessary diode drop , use 1 diode on the ground side if mine isn't of any help .

edvard · November 30, 2011, 12:42:07 PM

Overkill, schmoverkill... I was desperate to stop the hum and this did the trick.

It's not going anywhere but my breadboard anyways, most of the boxes I make get battery power.
I'll try your trick, I like simplicity.

The advantage of full-bridge is that the input is somewhat isolated from the output, so no noise sneaks in via the ground.

arawn · November 30, 2011, 04:11:16 PM

yeah thats a wheatstone bridge and is the only way to get full rectification with individual diodes. Although you can buy rectifier bridges for specific voltages etc. and they are pretty cheap.

wavley · November 30, 2011, 04:35:26 PM

Quote from: arawn on November 30, 2011, 04:11:16 PM
yeah thats a wheatstone bridge and is the only way to get full rectification with individual diodes. Although you can buy rectifier bridges for specific voltages etc. and they are pretty cheap.

Correct me if I'm wrong but, isn't it a Wheatstone when it's resistors and a Full Wave Bridge when it's diodes? I just always think resistors when I think Wheatstone, not to pick on semantics considering how often I'm wrong.

arawn · November 30, 2011, 04:55:11 PM

I was taught to recognize that as a wheatstone regardless of the components in use, could be wrong tho
whats more important is 1/2 wave or full wave rectification, 1/4 wave doesnt exist and is in essence useless it doesn't alter the waveform enough
1/2 wave will suffice but i always understood full wave to be the very best, most, optimal situation

chromesphere · November 30, 2011, 05:06:43 PM

Hey guys, been away last few days havent had a chance to try it. I'll try the one diode approach first, if that doesnt work ill try the full bridge. How critical is that diode 1n5817-1n5819? I have a heap of 1n4001's would they suffice?

By the way, i measured the output of my powerpack, its 9v's exactly.

Edit: Looking at the datasheets, the 1n5819 looks like its designed for rectifying, ill get some of these.

Paul

DavenPaget · November 30, 2011, 05:33:46 PM

Quote from: chromesphere on November 30, 2011, 05:06:43 PM
Hey guys, been away last few days havent had a chance to try it. I'll try the one diode approach first, if that doesnt work ill try the full bridge. How critical is that diode 1n5817-1n5819? I have a heap of 1n4001's would they suffice?

By the way, i measured the output of my powerpack, its 9v's exactly.

Edit: Looking at the datasheets, the 1n5819 looks like its designed for rectifying, ill get some of these.

Paul

1N4001 ... You're gonna get a much lower voltage out from them .
1N5817 gives you 450mV dropout @ 1A that's why i recommended that one .

chromesphere · November 30, 2011, 06:11:47 PM

I was going to mention that! I noticed in the spec sheet the low voltage drop. I'll try these with both circuits. I have a feeling if the voltage drop for full rectified is 4 x .45v's, its going to be too much of a drop (1.8v). I try the simple circuit first and see how that goes. Thanks again for sharing it Dave!
Paul

chromesphere · November 30, 2011, 09:26:30 PM

So, eager to try this out, i did a quick test and whacked in a 1n4001 (have to buy the 1n5819 on the weekend). I noticed a HUGE improvement in noise with the big muff. But i also noticed the tested output voltage was 8.4v as expected. So i'm wondering whether the noise reduction was a volume drop or a noise drop? If i had to guess id say its noise, the difference was night and day. I'm still getting some noise, but yeah its substantly less then without all this filter stuff.
edit: im going to also get that inductor and put that in the circuit as well. That should cover all bases. This was exactly what i was after, thanks to everyone for the input. That should be it for my instant questions. Maybe

Paul

chromesphere · December 01, 2011, 02:15:43 AM

Ok heres my conclusion on the whole thing, im talking practical experience here, i have no idea whats going on in the electron world.

The inductor made no improvement what so ever for my noise issues.

Infact, i have been mucking around with this circuit quiet a bit now, and for my powersupply (godlyke diasy chain), the only things that make any difference to noise, is a full 4 diode rectifier and 2 x 470uf to ground. This was mentioned sometime back in this thread, but i have only just bought the diodes to test it. I think with some pedals (FSH1 and Flanger 301 for example) the noise is self generated, its not coming from the power supply. But for others like the big muff...example: without the ciruict, amp volume on 5 = VERY loud noise. With the circuit = audible, but just a dull whistling sound.

I'm going to wire it up as it is and call it a day with this one. If anyone wants the final circuit let me know and ill draw it up.

Thanks again for all the help.
Paul

DavenPaget · December 01, 2011, 03:04:25 AM

Quote from: chromesphere on December 01, 2011, 02:15:43 AM
Ok heres my conclusion on the whole thing, im talking practical experience here, i have no idea whats going on in the electron world.

The inductor made no improvement what so ever for my noise issues.

Infact, i have been mucking around with this circuit quiet a bit now, and for my powersupply (godlyke diasy chain), the only things that make any difference to noise, is a full 4 diode rectifier and 2 x 470uf to ground. This was mentioned sometime back in this thread, but i have only just bought the diodes to test it. I think with some pedals (FSH1 and Flanger 301 for example) the noise is self generated, its not coming from the power supply. But for others like the big muff...example: without the ciruict, amp volume on 5 = VERY loud noise. With the circuit = audible, but just a dull whistling sound.

I'm going to wire it up as it is and call it a day with this one. If anyone wants the final circuit let me know and ill draw it up.

Thanks again for all the help.
Paul

Have you tried the single diode ? Save voltage drop and parts in cost .

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Huminator not huminating