AC/DC & POWERSTATION KIT BUILD THREAD

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awguitars
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by awguitars »

I've built and tested my power station.

48v reads fine but the other rails wont go above 21v or so and they are not at the end of the trim pot windings (the clicking occurs some time after)

i have used a 20VA 15-0-15 Volt transformer. is this insufficient?

I am using the trippler and i have the transfomer feeding in via two 15V in AC and center tap in 0V.

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Joe Malone
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by Joe Malone »

awguitars wrote:I've built and tested my power station.

48v reads fine but the other rails wont go above 21v or so and they are not at the end of the trim pot windings (the clicking occurs some time after)

i have used a 20VA 15-0-15 Volt transformer. is this insufficient?

I am using the trippler and i have the transfomer feeding in via two 15V in AC and center tap in 0V.
That is all correct 15vac x 1.414 = 21.21vdc unreg. You do not say what voltage you want but the general rule is that you will need the same VAC as you are after for the final +/-Vdc rails.
So if you want say +/-24vdc then you will need a 2 x 22vac to 2 x 25vac or a 2 x 12vac transformer wired as one 24vac.
The 48v will need to be set to doubler and turn the trim pots back until the voltage is about 20v for +/-V before changing the transformer.

You can work all this out in real time with the JLM calculator at the link below

NEW JLM Audio Power transformer VA wattage and Heatsink C/W rating calculator
http://www.jlmaudio.com/ACDC%20Calculator.htm
(Hold down shift and click on link to open in new window)
Joe :-)
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Sammas
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by Sammas »

Hi Joe,

I've just ordered a powerstation kit with the intentions of using to power a 51x rack (basically an 11 space API 500 rack).
I will be using +/-16 volt and 48v with the 6 Amp bridge rectifier. Power tranny is 2x18v 160va. Overkill, but it was cheap ($50aus) and
all they had.

What should I do with the two spare rails? Leave them unstuffed? or can I stuff them, set them to +/- 16volt also and just
let them sit there until they are needed (when I get a second 11 space api rack)?

Also, is it possible to add an inline fuse and LED for each rail to indicate it is operating properly? Say a 1.5amp fuse for each of the
16v rails connected in series, with an LED after it going to ground through the appropriate valued resistor? Perhaps a 315ma fuse for the
48v?

Cheers,

- Nath.

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Joe Malone
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by Joe Malone »

Sammas wrote:Hi Joe,

I've just ordered a powerstation kit with the intentions of using to power a 51x rack (basically an 11 space API 500 rack).
I will be using +/-16 volt and 48v with the 6 Amp bridge rectifier. Power tranny is 2x18v 160va. Overkill, but it was cheap ($50aus) and
all they had.

What should I do with the two spare rails? Leave them unstuffed? or can I stuff them, set them to +/- 16volt also and just
let them sit there until they are needed (when I get a second 11 space api rack)?
Best to fit everything and adjust the spare rails. We use the powerstation kit with both +rails and -rails in parallel with 3A sharing diodes for running our 11 way 500 racks. Adjust the power rails to 16.7v to make up for the diode loss. You can then run 2 x 11 way with most 500 modules.
Also, is it possible to add an inline fuse and LED for each rail to indicate it is operating properly? Say a 1.5amp fuse for each of the
16v rails connected in series, with an LED after it going to ground through the appropriate valued resistor? Perhaps a 315ma fuse for the
48v?
Yes use 3k3 in series with the leds on +/-16v and 10k on the 48v rail. Best to run fuses in the low voltage AC lines going to the powerstation so the power supply output impedance stays low. But you can run fuses on the outputs without a real problem as most 500 modules have local decoupling caps on them.
Joe :-)
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Sammas
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by Sammas »

Thanks for the info, Joe!

Do you mind if I share your post with the chaps on groupdiy? There are a few people intending on using the powerstation to power the 51x rack.

nikonet
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by nikonet »

hello,

I have few questions about ACDC kit, I would like +24V-2A, 0V, and 48V.

Is it possible to change something in order to have 2A?
I dont need -V, what i have to write in calculator, in -v box? 0V,0A?
If I need +24V, do i need 25V or 22V transformer?

Excuse-me for my language, i'm french......

And thanks a lot for all that work!!!!!

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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by Joe Malone »

Sammas wrote:Thanks for the info, Joe!

Do you mind if I share your post with the chaps on groupdiy? There are a few people intending on using the powerstation to power the 51x rack.
Yes that is fine to direct them to the post. I will get a drawing up on this thread of how we make the +/-16v 3A & 48v power supply soon.
Joe :-)
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by Joe Malone »

nikonet wrote:hello,

I have few questions about ACDC kit, I would like +24V-2A, 0V, and 48V.

Is it possible to change something in order to have 2A?
The AC/DC kit can only do 1.5Amp for the +V rail as that is all the reg can do and 4 of the 1N4007 need to be doubled to get past 1Amp. You would need the powerstation kit with both +V rails set to 24.7v and 2 x 3A diodes to share join both to make a +24v 3Amp power supply.
I dont need -V, what i have to write in calculator, in -v box? 0V,0A?
Yes enter 0Amps in any rails not used.
If I need +24V, do i need 25V or 22V transformer?
You can use a 2 x 22vac to 2 x 25vac with the AC/DC kit or Powerstation kit normally
or
1 x 22vac to 1 x 25vac if doing the neve mod shown below which works on AC/DC and Powerstation kits.
1. Short the bottom right hand corner cap with wire link.
2. Feed 22vac to 25vac in both AC in with nothing wired to 0v.
3. Set jumper to Tripler on ver 2 or later PCB's

Image

IGNORE THE WIRE FROM THE 2 DIODES TO THE + CAP IN THE CENTER
this was for old ver 1 PCB's with no doubler/tripler jumper
Joe :-)
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Sammas
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by Sammas »

Ok, I suspect something is seriously wrong with my wiring because I just fired up my powerstation and fried R14 (10R) which according to the schem only connects the star ground with the case.

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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by Joe Malone »

Sammas wrote:Ok, I suspect something is seriously wrong with my wiring because I just fired up my powerstation and fried R14 (10R) which according to the schem only connects the star ground with the case.
This usually means one of the TO220 voltage regulator metal tabs is shorted to the chassis. Always check the TO220 insulator kits are working properly with a ohmmeter between the chassis and the regs metal tab before powering up.
Joe :-)
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Sammas
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by Sammas »

Joe Malone wrote:
Sammas wrote:Ok, I suspect something is seriously wrong with my wiring because I just fired up my powerstation and fried R14 (10R) which according to the schem only connects the star ground with the case.
This usually means one of the TO220 voltage regulator metal tabs is shorted to the chassis. Always check the TO220 insulator kits are working properly with a ohmmeter between the chassis and the regs metal tab before powering up.

That looks to have been the problem. I did check them, but a last minute tighten must have created some continuity to ground.

It killed the 4 bipolar trimmers too (+/- V1 & V2).

It is all together and up and running. the voltages are set and it seems to be fine... generally.

The last powerstation I build was running a pair of 500 series modules so I only used a 500ma mains fuse (probably too much for this purpose). To
test this new supply I've used some of those same 500ma slow blow fuses. Without anything connected to the power supply, it occasionally blows this
500ma fuse when I first turn it on. It seems to happen a little randomly. I've replaced it a few times with another 500ma fuse and seems to work fine
until I turn it off then on (after quite a few hours of being off). I'm outta 500ma fuses now, so it has a 1amp slow blow in it.

This doesn't sound normal to me... but then again, I am no expert. Is the addition of the 5 amp bridge rectifier causing a great start up current? Or
could it be an issue with the switch I am using?

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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by Joe Malone »

Mains power fuses with toroidal transformers are more chosen to survive the toroidal power transformer turn on surge which is way higher than normal EI transformers. Most toroidal transformers manufacturers specify what type and rating this fuse should be on the side of the transformer. If the mains power fuse is to big due to the transformer surge then it is wise to fit smaller fast blow fuses inline with the PowerStation or AC/DC AC in's as well.

Also always make sure the top of the center bolt on the toroid transformer never shorts to the chassis as this will cause a shorted turn of about 300mV and draw several hundred amps causing the transformer to overheat.
Joe :-)
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Mats
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by Mats »

Hi.
I have just got my hand on tvo Amec classic channelstrips and need some advise on what to by.
I need some power to get it to work and I know it will be needing 18v +/- and some 5v and 48 for phantompower.
Is it ok to by 1 JLM AC/DC Ver. 3 and 1JLM TREX to get what I need?
The transformer will I by from a dealer i Sweden. It has the same spec's as the powerstation, but will be a lot cheaper for me. Ca 18euro.
How do I then connect the JLM TREX to the transformer?
I know the rest from this forum.
I'm a happy amatuer, with some wild dreams.

Thanx

Mats.

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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by Joe Malone »

Mats wrote:Hi.
I have just got my hand on tvo Amec classic channel strips and need some advise on what to by.
I need some power to get it to work and I know it will be needing 18v +/- and some 5v and 48 for phantom power.
Is it ok to by 1 JLM AC/DC Ver. 3 and 1JLM TREX to get what I need?
It would be cheaper and better to use the 5 rail Powerstation kit to get +48v +5v +18v -18v plus unused spare -V2 rail. Also on some Amek channels the 5v is not needed when racking out of a console at all or can be made to run on the +18v. If you have a schematic or any info email it to me and I can see if I can simplify the power down to just a AC/DC kit.
The transformer will I by from a dealer i Sweden. It has the same spec's as the powerstation, but will be a lot cheaper for me. Ca 18euro.
You will need a 2 x 18vac toroid usually around the 30VA size but I cannot be sure of the VA size without any schematic or other info on the Amek channels.
How do I then connect the JLM TREX to the transformer?
I know the rest from this forum.
I'm a happy amatuer, with some wild dreams.
Thanx
Mats.
You cannot directly connect a TREX to a AC power transformer as it has no diode rectification.
Joe :-)
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Mats
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Re: AC/DC & POWERSTATION KIT BUILD THREAD

Post by Mats »

Hi Joe.

I have send you a email over the cc1115 Amek channel. If you can calculate the power needed from this I will be glad.
I will order two powerstations as soon as I get some answer. One for this projekt and one for some Tore Seem channels.
I don't now the power needed for the Tore Seem but I will find out.
I sent the email to the sales adress. Coulden't find any better adress.
You can't read the picture if it's smaller. To big to put it out here.
Sorry for my bad Engslish.


Mats.

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