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protofuse

Using 5V and J2 pin

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hello,

I'm using my 5V psu with J2 with a core modified as shown there: http://www.ucapps.de/midibox_lc/midibox_ng_switching_psu.pdf

As I planned to make my own PCBs including core/ain/din/dout inside, I'm finishing my kicad schematics and I'm a little bit stuck by the part that concerns J1 & J2 and all the power supply stuff at the bottom right on this schematic: http://www.ucapps.de/mbhp/mbhp_core_v3.pdf

if I plan to never use J1 (& and >5v psu) should I remove the rectifier, the uln etc ? should I put them however ?

any help would be appreciated :)

all the best,

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fuse link=topic=13944.msg119927#msg119927 date=1250801545]

As I planned to make my own PCBs including core/ain/din/dout inside, I'm finishing my kicad schematics and I'm a little bit stuck by the part that concerns J1 & J2 and all the power supply stuff at the bottom right on this schematic: http://www.ucapps.de/mbhp/mbhp_core_v3.pdf

if I plan to never use J1 (& and >5v psu) should I remove the rectifier, the uln etc ? should I put them however ?

If you now using yours 5V psu with J2 its quite so ,redraw a schem  without   the power supply stuff at the bottom right on this schematic: http://www.ucapps.de/mbhp/mbhp_core_v3.pdf

on a new maded pcb.

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I put the schematic of psu pin J2 part in attachement to this post.

values will be the same as in the original schematic.

I guess, it is the answer :)

(TK, if I found the correct answer, may I win ... a capacitor? or a pretty optocoupler ?  :P)

5589_ddb334961ec329a1014d19160e73c24aa5c

5589_ddb334961ec329a1014d19160e73c24aa5c

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Is a plus sign is near pin 2 ?

Electrolytic capacitor value partly depends on which : external or internal 5 volts PSU will be used.

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not a + sign, it was the cursor I let here (sorry)

5v = +

GNDPWR = Ground

"external or internal 5 volts PSU will be used" what do you mean?

I'll use one ECM40 PSU to drive my 2 cores with 2 separate line (I mean cores take current directly on the psu)

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i say you can drop them. but you know that situation when you are in a hurry or a bit absent minded. it happens sooo easy, that you plug something wrong. with the conventional setup, you might blow up the regulator, in your case you can say good bye to your cores and what else is a bit sensitive. so if you are sure to do that, i would have psu, that is hard wired (psu inside the case) or at least have a very unique plug, so that nothing else fits.

just my two cents :)

cheers,

alex

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hello Alex and thanks a lot for your advice

I plan to have only one plug with only one position that fits.

I'll put a fuse just at the psu output in order to protect my 3 lines (2 pcbs + pots supplies)

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regarding the plug, i think of other equipment, standing near your midibox (keyboards, synths, whatever). so i meant using a plug, that fits in no other equipment at all (maybe mini-din, sub-d,...). just to clarify my thoughts, as i guess, you already got what i mean :)

about the fuse: i dont know what kind of fuse you want to use. i dont know whats available there, but an ordinary melting fuse will certainly be too slow. i guess, even a short voltage spike can burn the pic. according to the pic's datasheet, input voltage is rated at 4,2V up to 5,5V. i didn't find anything about a lethal voltage though :P

just out of curiosity: why don't you want to use the inbuilt power regulation?

bye, Alex

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just out of curiosity: why don't you want to use the inbuilt power regulation?

cause my PSU output is already regulated.

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i meant to use another psu as well, but i just discovered your thread about using a 5v psu http://www.midibox.org/forum/index.php/topic,13749.0.html

that explains, why you want use that psu :) if this is such a big unit, i would put the psu inside the protodeck, if there is the space. so that you plug the mains-cable directly to the unit.

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hehe

yes

I already put it inside the box

I had all in my box already

I also have my frontpanel etc etc

If I didn't have all these problems, I would have my protodeck already functionnal (obvious sentence.. but..)

my blog is here, if you are interested: http://www.julienbayle.net/diy/protodeck/blog/

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ok, thats a fancy one :) looks really nice!

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Regards using fuses to protect core etc: I would suggest you add a diode to each of your boards, so that if you do reverse the connections the fuse will conk out.

Hope this helps

regards

diode_protect.JPG

diode_protect.JPG

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