green power supply

hey, i can't seem to find the link to the parts list for the green power supply. i found it once. if i could find the schematic, that would help.
i ordered an extra PS pcb from peter, as i'm going to use it to push 24v for another project(i'm sure i'll post a couple times about it). from what i gather all i'll need to chage is a resistor rating. i can figure that out. what i'm wondering about is the 48v. the green pre design uses 15v and a voltage tripler to garnish the 48v. with 24v, i'll need a voltage doubler. is the curcuit much different?

david

Just drop the last diode and cap in the chain and you are there!

HTH!
Charlie

this is the correct parts list....?
http://recording.org/users/kev/gdiy_ps_2_parts.htm
all i need is the schematic and i'm golden.

david

Hi David

The PSU on my site is not the same as the PCB I sent ya.

Check your email for the schem.

Peter

the regulators lm317 and lm337 on the psu are getting very hot. is that normal ??

i´m using 2 micpres (v14) on one psu

when i power the mic pre my meter shows 40mA on the +15V and 40mA on the -15V. so why are those lm´s are getting so hot ?? :-(

Yes, it is normal for them to get hot, as in don't touch it As to the question why they get hot I guess it is just because they are doing alot of work. Even with no load the temp will rise on them.

You can always add some T0-220 heat sinks to them, which si what I did on my Green PSU over the weekend.

Cheers

Matt

Hi Ingo

Welcome to The Lab...

On my Green pres, when running 4 pres from one PSU, the regs get warm to the touch but not hot enough to be uncomfortable. The transformer secondary was 15-0-15 giving 21v before the regs, so they are dropping 6v.

What is your voltage before the regs?

Peter

hi peter,
that´s the problem. i measured everything except the transformer voltage
i had a 30-0-30. so matta is right, the regs have to work a lot :grin:
thanks for the help ;-)

i had a 30-0-30. so matta is right, the regs have to work a lot

Click to expand...

If that is AC, then I think it would be best to look for a 15-0-15v transformer. However if you cant get one, then some resistors in each side of the supply will help a lot.

30-0-30 will give you about +42v & -42v when rectified. Make sure your smoothing caps are rated for 50v!

You want to drop about 20v per side to save the regs. If you are drawing 40mA per side, the the series resistor would be 20/.04 = 500R, so use a 470R resistor in each side of the supply between the bridge & the regulators inputs.

20v drop will give you (20 x 20)/470 = .85w of heat, I would suggest a 2w reisistor.

So this would give you about 22v at the regulator inputs.

Peter

i already ordered a 15-0-15 transformer. i think it´s the best.

THANX

Hi everyone!

I've been lurking around here for a few months but have only posted once and didn't introduce myself, so a late hello.

I'm currently working on a pair of Green Pres and had a question about the Dagnall trafo. I'm a bit of a newbie and I'm not sure how to wire this thing up to the PSU. I've looked at PeterC's very tidy set up but the pictures don't really show which pins on the transformer are going where. Looks like he made a PCB for it. I would imagine I could do something similar on perf board.

Would someone be kind enough to illuminate this for me or perhaps shove me in the right direction.

Thanks

Kaspar

Can you give us transformer details?

Check this thread as well:

http://www.groupdiy.com/index.php?topic=10005&sid=3e9f662c414603fbad28d70bf780ea77

Peter

Transformer is a Dagnall D2035. I should say that I was expecting (newbie) to see three pins on one end and three on the other. As you I'm sure know, there are two pins at each corner or put another way four pins at each end. Obviously one pin at each end is either ignored or joined with another.

I'm probably missing something really easy

Trying to help here, got a datasheet?

Cant do all the work.....

Hi Peter,

I went to the Dagnall website but they have to email you a datasheet and nothing has arrived yet.

As soon as I get it, I'll pass it on.

Thanks

Kaspar

I'm away for a few days until Sunday, hopefully someone will pick it up.

Regards
Peter :guinness: :guinness: :guinness:

Found the following info ar the Farnell UK website. Maybe this will help me.

TRANSFORMER, 6VA 2X 15V; Power, AC:6VA; Voltages, primary:0-115, 0-115; Voltages, secondary:0-15, 0-15; Regulation:24%; Width, external:44.4mm; Depth, external:22.5mm; Approval Bodies:EN60950, EN60742, VDE0551, CSA; Flam

The Data sheet is here:

http://www.farnell.com/datasheets/15616.pdf

So, If I was looking at the top of the case (the blue part) the pins on the bottom would be:

0V 15V sec 0V 15V


0V 115V pri 0V 115V

Ok, so on the primary side I have two pins that are 0volts, these go to neutral pin of power plug. Then, I have two pins on the primary side that go to the hot pin of the power plug. Now I've got parallel right?

On the secondary side I have two pins that are 0volts and two that are 15volts. Using the post that KingKai wrote, in the thread that you suggested I read, my connections should be as follows.

the first OV pin to one of the psu 15V inputs.

The next two pins (15V and0V) to the psu O input. (same as G?)

The last pin (15V) to the other psu 15V input.

Have I got this right now? Thought I was a bit more knowledgable than I am

Thanks for all the help

Kaspar

Kaspar

It sounds right, but it's worth checking with the datasheet.

If you go ahead, try the connections without the PSU connected first. If something gets HOT, switch off immediately, there is an out of phase connection.

Regards
Peter

i am back with another newbie question. (i swear i am learning, despite how dumb i still appear!)

i am building my own PSU for the green pre (similar to Peters but with a few changes) and most of the parts are locally available, but i need to order the transformer. those dagnall pieces everyone else seems to be using look great but as far as i can tell, they only come from the uk, and i don't want to pay shipping.

so, can someone help me understand transformer specs so i can choose one from mouser, etc? it turns out my old EET text book is pretty lacking in regards to transformer info beyond the basics.

it appears that most are listed by VCT, which i gather from an earlier post to be the center tap voltage, but what does that mean, and how does it relate to anything that i'm interested in here?

I purchased mine from Newark here in the USA.

http://www.newark.com/