JSR06, a complete super regulator

[peranders]

As a future project I'm working on a very small holemounted super regulator with 115/230 volts in and +- 15 volt out. There will be no problem to change the voltage down to 3.3 volts.
If you want to take a peek at the schematics, see below.
http://sjostromaudio.com/hifi_files/jsr/jsr06r0schema_p1.pdf
http://sjostromaudio.com/hifi_files/jsr/jsr06r0schema_p2.pdf
http://sjostromaudio.com/hifi_files/jsr/jsr06r0schema_p3.pdf

The design goal is a ready unit for drivning a preamp or similar, 230 volt in and ultra low noise stabilized voltage out. The power supply will be very easy to build. It's possible that I will be able to offer ready built units but I won't promise anything.

An another goal is to make the unit a small as possible with chosen parts.

Of course will the pcb look like all my other designs, very high industrial quality with thick copper and groundplane.

The schematic is ready but not the pcb layout. When the pcb is made I want one to three beta builders. A good job will be rewarded.

I'll expect that I will have the pcb manufactured sometime in the second half of 2005.

Interesting features:

1 Regulator section identical to my JSR03 and JSR05 but they are snubberized*1) but both the preregulator and the series pass transistor will be on the same heatsink.

2 Option for LM431 or LM385, LM329 or simlilar types of voltage references.

3 Option for DIL08 or SO08 opamps

4 Expected output current max 200 mA (not verified yet how much which is possible).

5 The rectification can be done with an ordinary rectifier bridge or with fast recovery diodes in TO220 package or other types which will fit.

6 The charge currents are limited with a small resistance, reducing harmonics in the rectified DC voltage.

7 The smoothing caps may be ordinary ones or 10 mm snap-in high performance types.

8 The transformer is a 10 VA low profile type with 2 x 115 volt primairies which can be connected for 115 or 230 volts AC

9 The transformer is protected against transients with a varistor VDR.

The PCB will have WAGO connectors and  there will be an option for rather thick wires also soldered directly into the board.

*1) A combination of 100 uF in parallel with 100 nF creates two resonances', one peak and one dip. If you insert a small resistance in this circuit you can remove or at least reduce the peak. The peak occurs at a couple of MHz.

[Sigurd Ruschkowski]

Per-Anders,

this is good news!!!  

Everything on ONE PCB is what I like the best. All those small - but good - PCBs for a +-V creates lots of interconnecting wires.

I volonteer to build some JSR06 - min 2!

I have some ideas:

200 mA would be great as some phono preamps needs this kind of currents.
Maybe this means a higher VA on the transformer?

Use a double bridge rectifier (ie 8 TO220 diodes for +-V) with optional snubbers across each diode as on the RFB02.

Make room for polypropylene caps. Large ones in paralell for smoothing caps,
and smaller ones for the rest of the board.




Sigurd

[Sigurd Ruschkowski]

Some LEDs for the raw PS and for the regulated PS.
Maybe blue SMD LEDs?
4 of them per board.

Fuse holders would be nice to have.




Sigurd

[peranders]

There will be no extra LED's, sorry but you will still have two (any colour you like) and maybe two more if you have a low voltage regulator.

The design is "frozen" at the moment and I have started with the pcb layout. The positive half has all it's parts placed and half of the traces are there. I'd say 30% is ready.

The PCB will have WAGO connectors and  there will be an option for rather thick wires also soldered directly into the board.

Board = 102 x 137 mm, 5.4 x 4 "

[peranders]

The pcb is ready now and look like this:


Other info can be found here:
http://home.swipnet.se/~w-50719/hifi/jsr06/downloads_jsr06.html

The text in the pages isn't fixed yet so download schematics and partslist. There is all basic info but some things need to be explained because all options aren't easy to see, I'll guess. Feel free to ask in the meantime.

[peranders]

The prototype is working now!  

[Sigurd Ruschkowski]

What a beaty she is. She = JSR06  

To see her in reality and not just as a PCB drawing makes her shine!

The mirrored layout is looks wonderful, Per-Anders.
You even made the heights of the transformer, caps, and heat sinks the same.

I look forward to building two units of this design!
Them I will use separate Schottky diodes instead of the rectifier bridge, and it even looks like you have made more space for all the 100nF caps, so I can put in the red WIMAs polypropylenes, or blue RIFA PFRs or 450s    
Maybe a blue LED - if I use blue RIFAs or it will stay red if I use the red WIMAs.

Excellent work!


Regards,
Sigurd

[peranders]

Thank you , Sigge. I'm pretty pleased with the results myself. It is directly from the computer, soldered.... boom it worked right away.

A few things to bear in mind:

The transformer has a bit low voltage for preregulator and 15 volts out. 70-100 mA is possible. You could increase the current by removing the preregulator and R19, E19.

A blue LED will further decrease the possible output voltage at max current.

[Sigurd Ruschkowski]

I have had some problems with the blue LED on my JSR03/05. Especially at higher output currents as you mention.
I am sucking 240 mA out of my JSR03/05 on a long time test as of now. I had to increase the input voltage by changing the transformer. No problems at all after 20h of testing

I now have 33 V input to the ble LED +-24 VDC versions of my JSR03/05s and I have no problems taking out 240 mA (well cooled regulators of course!). 30V input did not work.

The latest and best OPamps today do not work with +-15V. I will be using +-12VDC for some AD8610. and AD825s and AD8065s.



Sigurd

[peranders]

The regulator has a drop-out voltage and it becomes more at higher output current.

[Sigurd Ruschkowski]

My work on the JSR06s has started.

I am useing Schottky diodes instead of diod bridges.





Sigurd

[peranders]

Tested more now.

224 VAC in:

12 V, 240 mA out in both regulators will work with 2 x 15 VAC 10 VA transformer.

It may be an idea to exclude R19, E19. You will win 0.6 volts in raw voltage.

15 V out with 2 x 15 VAC transformer is limited to 50-70 mA

2 x 18 VAC transformer will give you 240 mA +- 15 volts out. This is a bit hard load but 200 mA can be garanteed.

Otherwise, I'm pretty pleased and the design is verified to be 100% error free both in the pcb and in chosen parts.

[Sigurd Ruschkowski]

Excellent specs!
240 mA is more than enough fo my applications!

12V is what I will use for my amps.

On the photos above, you can see that I am using jumpers for R19 and E19 already. I guess that my using Schottky rectfiers will also help in getting a bit more raw voltage.

I got the transformers and heatsinks from ELFA today  



Sigurd

[qusp]

which schottkey diodes should be used? I am not at all familiar with them. I will use fast recovery or schottkey as the rectifying diodes are difficult to find. is better performance gained using the 2200uf rather than 470uf? I was thinking of using 680uf blackgate NX ir 2200 BG type FK.  can you please recommend a transformer with dual 25-30V primaries that will fit? I would like to use this board to act as a main supply/prereg for some SSR01/02 and JSR01 at voltages ranging from 5vdc-18vdc, so it should put out at least 24vdc??

[qusp]

i'm assuming I will have to change opamp to get greater than 18vdc (as well s the feedback/gain of course)?? was going to use LM329 for reference. would LME94710 do OK for opamps? or AD797, but this would need some compensation yes? or have you managed to get past all the issues with stabilty that others have reported with AD797 in the jung type regs? perhaps just OPA134?