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HelderS

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  1. Hi, Audioguru, Ok, I must wait now, to buy some 44V opamps. And after I change them, wich major changes to other components to make this PS Work ?? If I get an output of 20 V @ 1,5A, I really wouldn't mind... :-) Regards, Helder Silva P.S.: By the way where are you from, Audioguru? I'm from nearby Coimbra, Portugal.
  2. Hi, Audioguru, why do you added de negative supply voltage??? I measured the voltage betweeen pin 4 and 7and it were +/- 40 V, doesn't this volage includes already the negative voltage supply?? Regards, Helder Silva
  3. Hi, Audioguru, so I've to change my Q2 to a TIP31A, and can I use a LM741 ampop instead the OPA445AP, once it may be more difficult to get where I live. If not, can you give other alternatives. And I have to say that ALL my project has been made with the original parts proposed in the website, except my transformer wich have 26.7 VAC @ 2.5 A, for maximum ratings. I'm not at home, so I can not measure now the opamps supply. Regards, Helder Silva
  4. Hi, Audioguru, here it goes my results: 2) Without a load on the project measure the voltage at the slider of P2. It should be about +1.7V. If it isn't, check the vaues of R7, R17, R18 and P2. Here, I measured +1.8V 3) If the values are correct but the measurement is wrong, measure the voltage at pin 6 of U1. It should be about +11.2V. Here, I measured +10.94V , IS IT TOO LOW??? wHAT DO YOU THINK ABOUT THE VALUES i MEASURED, I STILL CAN'T HAVE MORE THAN 50 mA AT THE OUTPUT... R2 BECOMES REALLY HOT AT YOUR POINT 5) CONDITIONS? aNY CLUE? THANKS
  5. Ok, audioguru, I know how to make the claculations, I would like to know why can't I have more than 50 mA??? Regards, Helder Silva
  6. Hi, Audioguru, sorry about the stupid question, but to measure the voltage in R7, I have to short circuit the output, right? That's What I've done, and I measure at R7, a voltage of 0.022 V. wich gives 46.8 mA. What's wrong? Why can't I have more than that measured current (46.8 mA) ?
  7. Ok, my BC557 have already arrive. So, i've put him at his place, and turned on my PS, but I'm having a doubt wich is, how can I measure the output current ?? I've built my PS entirely original, I've done none of the changes proposed in this forum... (I thought the project on the website was CORRECT)
  8. Hi, everyone, I've completed the Power Supply 0-30V @ 0,002 - 3A, but i've done a stupid mistake, i have turned it on before putting the ICs in the respective sockets, sou when I turned it on, the PS made a sound, wich I think, came from a capacitor. I've cut the power off right after, but after inserting the ICs, happened this strange thing, the PS turns on the Led (Current Limit) and never turns off. Maybe I 've burned the transistor Q3??
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