Need to build a power supply + - 17.5V , 48V (Newbie)

Hi,
I'm just getting my way into DIY and Electronics.

I need to build a power supply with a Toroidal transformer capable of delivering:

-17,5v
+17,5 v
0 v
48 v

What type of toroidal transformer do I need to buy?

What circuit for the power supply should I use? is there anyone selling pcb that I could use on this power supply?

thanks

You can use the SSL9K power supply. I think you can get them from Gustav. Check the stickies in the black market. Should be cheap.

As for the toroid, get one with dual secondaries. If you're in the states, the cheapest would be from www.antekinc.com.. call them, don't email. Look for something around 18-20V. But, you need to know how much current your circuit needs so you know the VA rating of the trafo.

good luck

I dont know how much current the circuit need to be honest, its a channel strip that im racking:

http://www.groupdiy.com/index.php?topic=27689.0

I think it should be quite low anyway, since its a sinple circuit.
How can I know exactly?

You're better off posting in the original thread, since this is related. You may have gotten a better answer off the bat from someone familiar with the circuit.  I guess it comes down to adding what all the ICs need, so check the respective datasheets.  Add a margin.  I've never had to calculate it for any of my projects, so not entirely sure if there is more to it.

thanks , I didn't post in the project thread, because I have a lot more going on there, and it would be confusing.

how would I make the ssl 9k power supply , to provide 17,5 volts instead of 18v?

You could also go with one of these if you want to get real accurate.

http://www.jlmaudio.com/JLM%20Power%20Supply.htm

The AC/DC ver 2 kit should work well for you.

Casey

Thanks,
I will check that.
I've been to JML site before, and people generally like the products, I just get confused with the website , its all over the place.
Its a good solution probably, don't know how much would be the shipping costs from Australia to Europe.

Still need to find the right toroidal transformer to use....

To remove about a half-volt from the ±18V outputs of the KPS-1, just throw a diode in series with both outputs... instant half-volt drop!

By the way, most circuits will be just as happy with ±17V or ±18V... I don't recall ever seeing anything that would work on ±17.5V which would complain about ±18V.

Keith

SSLtech said:

To remove about a half-volt from the ±18V outputs of the KPS-1, just throw a diode in series with both outputs... instant half-volt drop!

By the way, most circuits will be just as happy with ±17V or ±18V... I don't recall ever seeing anything that would work on ±17.5V which would complain about ±18V.

Keith

Click to expand...

Nice, So I will not even throw a diodes in there, I will just run it at 18 volts.

By the way there any advantage of running it at 18volts ?

I'm asking this because there's equipment that runs at higher voltages to increase gain and signal to noise ratio, but 0.5 volts is not that a big difference.

Neither gain nor signal to noise ratio will be affected by a change in supply voltage.

Only the MAXIMUM output level which can be generated, and therefore the PEAK signal can be affected, which -if the noise remains unchanged- therefore equates to a slightly increased theoretical signal-to-noise ratio, but if you need the extra half-volt to avoid clipping, you're running rather closer to the rails than is realistically comfortable... the electronic equivalent of replacing sleep with coffee... -It might seem appealing, until your nerves register their complaints! 

Keith

Thanks for the explanation Keith.

I will use the SSL psu board from Gustav, it will be cheaper than using the JML psu.


Keith I want to ask you something also relating to my project. This PSU is for a channel strip i'm Racking, the 2nd channel on the strip is the tape/monitor return with EQ. I want to modify it to a Mic Pre channel, my first idea was to copy the mic pre in the 1st channel and connect it to the monitor channel.

But since the idea for using the SSL 9K PSU came I just thought that it would be better to do the SSL 9k pre and just connect it directly to the tape/monitor return EQ section, and from there to a balancing board.

What do you think about this? Can you give a look to the schematic notes I made?

thanks

That looks like it shoudl work just fine.

Keith

Thanks a lot Keith your input and words are always a boost for me.

Just waiting for the SSL 9K boards to arrive , and then I will have an Oxford meets Manchester unit!!!!!!!!!!!!!!!!!!

This project continues on this thread.

http://www.groupdiy.com/index.php?topic=27689.msg377251#msg377251

Thanks for all your help

Coming from some one who's in the same place as you, send an email to JLM explaining what you're up to, he'll totally hook you up.  His stuff is top notch and there's step by step build instructions on his site for the basic power supply which you can fine tune with trimpots to your exact voltage.

Hi,
thanks for your kind help, but I learned a lot since I started this thread. (1 month)

LOLOLOL

I still don't know anything about electronics, but I was abble to build the SSL 9k pre, PSU and balaning board, and I will use those for the project.

the JML it's really nice, but the SSL 9k PSU provides all the voltages I nees, is really simple and much cheaper
(price and shipping)

have a lot at the next steps on this project,here:

http://www.groupdiy.com/index.php?topic=27689.msg377251#msg377251