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Projects => General Questions => Topic started by: TwistdDeth on August 03, 2013, 03:07:50 AM

Title: diy dc power brick
Post by: TwistdDeth on August 03, 2013, 03:07:50 AM
Anyone know of a good schematic for a power brick. I am thinking of at least six to eight output. My input voltage would be 12vDC at 1 amp and my output would be a single 12vdc and the rest regulated 9vdc.
Title: Re: diy dc power brick
Post by: davent on August 03, 2013, 04:22:54 AM
Lots of good info here. http://www.geofex.com/article_folders/spyder/spyder.htm
Title: Re: diy dc power brick
Post by: jimilee on August 03, 2013, 04:29:25 AM
I haven't seen the actual board,but didn't someone post one in the osh park thread?
Title: Re: diy dc power brick
Post by: RobA on August 03, 2013, 06:04:22 AM
Quote from: TwistdDeth on August 03, 2013, 03:07:50 AM
Anyone know of a good schematic for a power brick. I am thinking of at least six to eight output. My input voltage would be 12vDC at 1 amp and my output would be a single 12vdc and the rest regulated 9vdc.

Is there a reason you want to use a DC input? It should be easier to do a clean power supply using an AC transformer of some sort. It's pretty simple to put together a power supply based on an AC output wall wart.
Title: Re: Re: diy dc power brick
Post by: stevie1556 on August 03, 2013, 08:37:15 AM
There is a good one on SmallBear somewhere, and I believe he also seels the parts for it.

Sent from my thumbs using Tapatalk!
Title: Re: diy dc power brick
Post by: TwistdDeth on August 03, 2013, 01:34:56 PM
I have a few 120vAC to 12vDC wall warts, was thinking of using instead of buying transformers and hoping I get the primary and secondary's wired correctly. This way the pcb will only have to step down from 12 to 9vDC. I was thinking a common ground wired to the tip at each output and for the positive side would be the capacitors & regulator, of coarse going to the shield. (LOL, this is funny to me because I design substations that are energized from 12.5kV to 500kV AC, and am having trouble with a 9v distribution brick.)
Title: Re: diy dc power brick
Post by: RobA on August 03, 2013, 02:29:03 PM
Quote from: TwistdDeth on August 03, 2013, 01:34:56 PM
...(LOL, this is funny to me because I design substations that are energized from 12.5kV to 500kV AC, and am having trouble with a 9v distribution brick.)
:D That is a good one. I think it happens to everyone when you start something new and is probably worst when that new thing is closer to something you already know -- any small thing is magnified by how much you do already know. The good thing is that you'll have it faster and better than anyone else. And tube amp's would be nothing for you. I really want to build one, but that high voltage (tiny for you) has me totally freaked.

I think the main reason for using the AC power sources is that you get away from the noise that's inherent in switching power supplies and the like. I'm working on a bench power supply because I blew up my cheap power brick. (I swear I'm going to get this soldered this weekend ;D.)

I didn't want a very big thing on my desk, so I didn't want internal transformers. So, I went with an external AC-AC transformer and just followed the basic prescription for one that uses internal transformers like the Spyder linked above.

I wanted 15V, 9V,  and  5V, so I went with this AC-AC transformer from Mouser http://www.mouser.com/ProductDetail/Triad-Magnetics/WAU12-1500/?qs=%2fha2pyFadujrNpP0fcluI%2fuJv9p%252bKBVvHFrb66Ji5ZPI12Kfr%2fwBvA%3d%3d (http://www.mouser.com/ProductDetail/Triad-Magnetics/WAU12-1500/?qs=%2fha2pyFadujrNpP0fcluI%2fuJv9p%252bKBVvHFrb66Ji5ZPI12Kfr%2fwBvA%3d%3d). Then combined a couple of the ideas (regulated, ultra-clean, and four output) from here http://www.generalguitargadgets.com/projects/24-power-supplies (http://www.generalguitargadgets.com/projects/24-power-supplies) to get one that does what I want.
Title: Re: diy dc power brick
Post by: RobA on August 03, 2013, 02:40:02 PM
If you do want to stick with the DC transformers, then I think what you described will work fine. You can pretty much do the distribution portion of the GGG multi-tap one and ignore the transform section.

The two power bricks I have are 18V and 9V which is convenient to have and they use an 18V DC input and then use buck converters to drop it down to 9V. I guess they do this because it's more efficient than using a regulator. But, that's what blew in the power supply that went bad on me.
Title: Re: diy dc power brick
Post by: Willybomb on August 04, 2013, 02:10:57 PM
They're probably the easiest project to build, as long as you're careful with your 240v wiring.  Here's mine:

http://www.madbeanpedals.com/forum/index.php?topic=9871.0

I used this schematic, omitting the 12v and 5v regulators and power LED, and replacing C3 with a 220uf as per the Spyder basic schematic:

http://www.instructables.com/files/deriv/FZG/YM90/G5703OX4/FZGYM90G5703OX4.LARGE.jpg

Looking at the GGG schematic here: http://www.generalguitargadgets.com/pdf/ggg_ps_rps_sc.pdf
is a pretty good representation.  I just have a couple of 10uf between the regulator and the 220uf..

Willy.