DC jack hum/ battery no hum

[Jdansti]

It sounds like your PS has multiple outputs.  If it has an output of at least 12VDC, then you're set. Just add an LM7809 regulator (with heat sink or attached to metal enclosure), and you're regulated.  No need to mess with mains voltages.  Put this in a small box in line between your wall wart and whatever you're powering.

http://www.researchcell.com/general/7809-pin-and-circuit-diagram/

[Kipper4]

No multiple outputs but a switch to change voltage.
I guees this IC power regulator could be integrated into a circuit for future use yes?

[giappui]

you can try this

[deadastronaut]

you have 3 options:

1: hum along with it .

2: buy a kazzoo 

3: buy a good psu...essential 

though option 1+2 are fun for an approx 17 minutes, i got bored with that and bought a psu from effectspedalpowersupplies.com. never had a problem..(around £25.00)

[J0K3RX]

http://visualsound.net/1-spot-combo-pack/  <---buy it

[Kipper4]

Rich, I would not normally recommend a kit on a diy forum but many years ago I bought a 1.5 amp  power supply board kit from Maplin. It's a Velleman project and has never, ever given me any hum or other artefacts no matter what the mains supply. Its well regulated and incorporates a trim pot for voltage regulation. just add a transformer...Worth a look.

Any ideas where to find the kit or schematic from Maplins / Vellman Please

[Kipper4]

Thanks for the links guys
I love those simple 1 box does it all daisy chain supplies. One has even been reviewed by a Dead Astronaut.

[J0K3RX]

This looks cool although I don't need one... Forget charge pumps... I might make a DIY version of this?
http://www.godlyke.com/power-all/godlyke-power-all-accessories/iso-pump-voltage-converter

This also
http://www.godlyke.com/power-all/godlyke-power-all-accessories/ground-hound-ground-isolator

[stallik]

<Any ideas where to find the kit or schematic from Maplins / Vellman Please>
Velleman kit no P1823
Maplin code VE58N
It's LM317 based
I have an unbuilt kit if you have questions re the layout etc

[stallik]

This looks cool although I don't need one... Forget charge pumps... I might make a DIY version of this?
http://www.godlyke.com/power-all/godlyke-power-all-accessories/iso-pump-voltage-converter

This also
http://www.godlyke.com/power-all/godlyke-power-all-accessories/ground-hound-ground-isolator

Nice. Please share if you do

[Kipper4]

<Any ideas where to find the kit or schematic from Maplins / Vellman Please>
Velleman kit no P1823
Maplin code VE58N
It's LM317 based
I have an unbuilt kit if you have questions re the layout etc

This is the fella

http://www.velleman.co.uk/contents/en-uk/p198.html

sorry if this causes offence to Vellman but heres the pdf

http://www.velleman.co.uk/manuals/k1823.pdf

simple enough to build but at that great price i'd be just as well to buy the kit from them. Rather than source all the parts inc heatsink etc
Having said that i think i'd rather put an external pot in the top of the enclosure.

Thanks for the help stallik

[pinkjimiphoton]

I dont know if the supply is regulated (probably not) but i have it on the 7v setting the reason being it measures 8.85 volts on the DMM. i figured its as near as i'm going to get to 9v from its setting. I'm sure i checked them all before and it was the closest.

I double checked the cap voltage rating one is 25v the other is 50 v across the supply.

The thing i dont get i guess is how come when both supplies are similar voltage (DC jack and Battery) why does it only hum when powered by the dc jack?

And why when i checked to old unboxed build did it not hum?

if it was something on the circuit wouldnt i get the hum no matter what the supply. Although i am aware that battery supplies are inherantly less noisy.

btw my enclosure is powder coated and i scraped that away at the input jack to ensure a good ground connection. but again wouldnt the resulting hum be present what ever the 9v supply?

I'm sorry if this is annoying. I'm sure its been asked a million times already.

rich
make sure whichever cap is across the rails closest to the input of the power supply is higher voltage than the next cap in line, and higher value.

a 50v 220u cap say affter a 25v 100u can be a problem as i discovered when i built a rebote.. the bigger cap could "discharge" thru the smaller cap before it  and make a hell of a hum, and cook the regulator and 2399. i dunno if this applies to you or across the board, but it's just a thought bro.

[Kipper4]

Intresting thanks for the tip off Jimi.
Appreciated. Makes a note in my little book of tricks.

[stallik]

Hey Rich - the Velleman kit does not come with a heat sink! still a good price though, which is why I've never bothered cloning it.
I tend to use 2 of them and a 15-0-15v transformer. That way I get 2 separate supplies, one 12, one 9v. Or whatever you want. Even doing this, I've never had to use anything more than a small sink on each board. My first one was built 10 years or so ago. I put it in a big plastic ps box but recently I've started using standard hammonds and being very carefully with insulation and earth.

The board I still have to populate is intended as a little test supply for my workbench. I was intending to put the trim pot on the outside of the enclosure ( using a standard pot) and installing a meter on the face but I've just not got round to doing it...

[Jdansti]

No multiple outputs but a switch to change voltage.
I guees this IC power regulator could be integrated into a circuit for future use yes?

Sorry-that's what I meant- a switch to change voltages. Does the switch on the wall wart have a 12V setting like this?

[Kipper4]

sure does John

[Jdansti]

Great!  This will get you as regulated as an 80-yr old man who eats prunes twice a day.

Edit:  ...but with less noise!!!   



Be sure to heat sink the regulator.

[Kipper4]

Great stuff thanks John

[mistahead]

TO-220 is very nice good solution to a lot of problems...

Does anyone out there (off the top of their head) want to save me some time and recommend comaparable for 12,18 & 24v? I'm terrible at part suitability hunting, datasheet hunting not so crap.

[Jdansti]

http://www.divilabs.com/2013/04/all-about-voltage-ragulators-lm-78xx-lm.html?m=1

LM7805 +5V
LM7809 +9V
LM7812 +12V
LM7815 +15V
LM79XX -XX
•  Output current in excess of 1A
•  Internal thermal overload protection
•  No external components required
•  Output transistor safe area protection
•  Internal short circuit current limit
http://www.hep.upenn.edu/SNO/daq/parts/lm7815.pdf

LM317
• Output-Current In Excess of 1.5A
• Output-Adjustable Between 1.2V and 37V
• Internal Thermal Overload Protection
• Internal Short-Circuit Current Limiting
• Output-Transistor Safe Operating Area Compensation
http://www.fairchildsemi.com/ds/LM/LM317.pdf