AC/DC & POWERSTATION KIT BUILD THREAD

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Re: AC/DC & POWERSTATION KIT BUILD THREAD

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matthewsawicki wrote:Hey!

I've been wanting to purchase a couple of these kits to retrofit into an older mixer that I have as well as to replace the PSU of ADA8000's. I was just hoping to hear that this would be a good idea or not.

The mixer is 16 channel inline console with mic pres and phantom power requiring ±15v rails, +5v rail, and +48 phantom. From what I've seen, 300ma should be plenty for the phantom, and I was planning on getting the 6amp mod.

ADA8000's need ±15v, +5v, and +48v as well. I was thinking the 6amp mod could power 2 or possibly 3 of the units. Any advice on this?

I was planning on matching them to your World Transformer kits as well.

Many thanks!
Sound fine as most 16 channel console do not draw 1.5A for +/-15v but would have to check what the 5v rail runs to make sure it is within the 1.5A. Do you have a schematic or any info on the desk?

For the ADA8000 3 units will be fine on 1 powerstation.
Joe :-)
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tonefreq
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by tonefreq »

Hi Joe,

I've bought about 15 of these AC/DC boards from you, mostly the V3, and had good luck with them. This last one is giving me all sorts of troubles though, it's a V4 board as you can see in the pic. I'm using a Triad VPT18-1390 transformer http://www.mouser.com/ds/2/410/VPT18-1390-224254.pdf wired in parallel on the primary for 115VAC, and Series on the secondary for 18VAC CT I soldered the black and yellow wire to the AC inputs on the board, and the orange and red to the 0V as you can see.

The problem i'm having as that the trimmers will not adjust any of the voltages, they remain +13.5, -13.5 and +42.4. I double checked the parts, and reheated all the solder connections in case I had a cold joint. Nada. Still gives me the same issue. Is this a grounding problem?? I 'm reading 10R between 0V and chassis. I have the IEC Earth tied to Chassis ground as well. Any help would be greatly appreciated, I'm stumped at the moment! Many thanks!
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

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tonefreq wrote:Hi Joe,

I've bought about 15 of these AC/DC boards from you, mostly the V3, and had good luck with them. This last one is giving me all sorts of troubles though, it's a V4 board as you can see in the pic. I'm using a Triad VPT18-1390 transformer http://www.mouser.com/ds/2/410/VPT18-1390-224254.pdf wired in parallel on the primary for 115VAC, and Series on the secondary for 18VAC CT I soldered the black and yellow wire to the AC inputs on the board, and the orange and red to the 0V as you can see.

The problem i'm having as that the trimmers will not adjust any of the voltages, they remain +13.5, -13.5 and +42.4. I double checked the parts, and reheated all the solder connections in case I had a cold joint. Nada. Still gives me the same issue. Is this a grounding problem?? I 'm reading 10R between 0V and chassis. I have the IEC Earth tied to Chassis ground as well. Any help would be greatly appreciated, I'm stumped at the moment! Many thanks!
Power supply is working perfectly as you describe.

I think you are confused by the 18vac ct which is only 9vac per side so gives 9vac x 1.414 + 5 to 10% unloaded = +/-13.5vdc unreg. (3 x 13.5 for the 48v rail in tripler = +42vdc unreg)

I think the transformer you really wanted to buy would have been a 2 x 18vac or 36vac CT which would give you a max dc or 18vac x 1.414 + 5 to 10% unloaded = +/-27.5vdc unreg good for making +/-15 to +/-18vdc regulated rails.

If the power supply is not running at full high load. You can wire the transformer you have as a single 18vac with the centre tap not connected to anything. And wire black to 0v and yellow to one AC in. This will give you the same rails as the 2 x 18vac above but only be running half wave rectification where as the 2 x 18vac would make full wave rectificaion so the unreg dc rails are smoother for the regs to work with.
Joe :-)
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tonefreq
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by tonefreq »

Thanks joe,
But why aren't the trim pots changing the doc voltage at all? Or would I have to adjust them down quite a bit to see a change? Either way, I think I can use it as is, I'm just powering one API type pre and I think phantom should run off of 42v, yes? Thanks for your help!

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Re: AC/DC & POWERSTATION KIT BUILD THREAD

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tonefreq wrote:Thanks joe,
But why aren't the trim pots changing the doc voltage at all? Or would I have to adjust them down quite a bit to see a change? Either way, I think I can use it as is, I'm just powering one API type pre and I think phantom should run off of 42v, yes? Thanks for your help!
The 5k 25 turn trim pot as a range of 50v on the AC/DC & Powerstation kit and comes set new to about half way so about 25v. If your unreg dc voltage is under the set trimpot voltage then nothing will happen until the trim pot value is small enough to pull the regulator output lower and give regulated dc out.

The only time you do not want to wind the trim pot down is if you know the unreg voltage is high enough and winding the pot doesn't cause a change as this usually means a fault or dead regulator. To keep winding the trim pot down in this case will make the 120R and trim pot burn out.
Joe :-)
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xazrules
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by xazrules »

hi, i need an output V of +/- 15v from my acdc kit.
my secondary windigs of my transformer are 2 x 15v, which component i need to populate the pcb?
can i use your default BOM?
thanks!

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Re: AC/DC & POWERSTATION KIT BUILD THREAD

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xazrules wrote:hi, i need an output V of +/- 15v from my acdc kit.
my secondary windigs of my transformer are 2 x 15v, which component i need to populate the pcb?
can i use your default BOM?
thanks!
See attachment
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xazrules
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by xazrules »

thank you!
so can i leave the 48v part out?

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Re: AC/DC & POWERSTATION KIT BUILD THREAD

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xazrules wrote:thank you!
so can i leave the 48v part out?
Yes if you do NOT need the 48v rail you can leave out all parts in the 2 red boxes in the above post attachment.
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xazrules
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by xazrules »

ok, last thing last i promise :D
where can i solder a led?

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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by Joe Malone »

xazrules wrote:ok, last thing last i promise :D
where can i solder a led?
A power led with series resistor can be wires across the +V and 0v. Usually wire resistor to +V, other end of resistor to LED Anode (long leg), LED cathode (short leg) to 0v.

Formula for resistor for standard 3 & 5mm LED's

V = voltage @ +V
R = V/0.01

Just make R the closest standard value

So for +15v R would be 1500 or 1.5k
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quantyk
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by quantyk »

Hello - just got the AC/DC kit with the world power transformer 2x15 30VA, in hopes of supplying +/- 25V for a Neve amp card (10852) project and put it together last night.

After testing today, but it seems that the trims are only taking the voltage up to 23.7ish volts, everything else seems fine. After re-reading these threads, it seems now that i need at least 25V on the secondaries of the power transformer, for higher unregulated DC, in order to get 25V regulated, so I just wanted to confirm this. I thought perhaps there was a way to connect the World Transformer kit to get +/- 25v from the AC/DC, but perhaps not.

I have 2 surplus transformers that each have 115V primaries and 26V secondaries, rated at 40VA, so I think I'd be in good shape to use these.
i was also wondering about an earlier post where Joe mentioned the benefits of having 2 x 22 coils for wave rectification, and since these 26V transformers are identical, I think I'll figure out how to use them. Since they are both single coil, would it be as simple as connecting their secondaries to the AC/DC inputs for 0 & VAC? Or would it be better to use use one transformer. I might as well use them if they will help matters in terms of stability, lower ripple, etc.

thanks very much for any insights here.

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Re: AC/DC & POWERSTATION KIT BUILD THREAD

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quantyk wrote:Hello - just got the AC/DC kit with the world power transformer 2x15 30VA, in hopes of supplying +/- 25V for a Neve amp card (10852) project and put it together last night.

After testing today, but it seems that the trims are only taking the voltage up to 23.7ish volts, everything else seems fine. After re-reading these threads, it seems now that i need at least 25V on the secondaries of the power transformer, for higher unregulated DC, in order to get 25V regulated, so I just wanted to confirm this. I thought perhaps there was a way to connect the World Transformer kit to get +/- 25v from the AC/DC, but perhaps not.
Yes you have the world power wired to the AC/DC as 15vac - 0v - 15vac so max will be about +/-24vdc unreg. TO get +/-25v regulated you will need to wire the transformer as 1 x 30vac between one of the AC in's and 0v on the AC/DC. So world power kit output wired A to 0v on ac/dc, B connected to C, D to Ac in on ac/dc kit. Set ac/dc to doubler for 48v rail.
I have 2 surplus transformers that each have 115V primaries and 26V secondaries, rated at 40VA, so I think I'd be in good shape to use these.
i was also wondering about an earlier post where Joe mentioned the benefits of having 2 x 22 coils for wave rectification, and since these 26V transformers are identical, I think I'll figure out how to use them. Since they are both single coil, would it be as simple as connecting their secondaries to the AC/DC inputs for 0 & VAC? Or would it be better to use use one transformer. I might as well use them if they will help matters in terms of stability, lower ripple, etc.
That would also work as long as you keep phasing correct but overkill of the Neve card as the rewire mentioned above will make the world power kit work perfectly.
Joe :-)
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quantyk
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by quantyk »

Fantastic! thanks so much for the quick and clear response. the instructions for the AC/DC kit were great and easy to follow - did I miss something similar for the world power kit?

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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by quantyk »

And i suppose if i got hasty and didn't change the jumper back to doubler, then the +48V caps would blow? perhaps because now they're getting way more volts than they're rated for? :oops:

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