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Posts posted by HelderS
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Hi, Audioguru,
If you measure only 40V from pin 4 to pin 7 and your positive supply is 39.7V then your negative supply isn't working. Check the polarity of its diodes.
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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 -
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 -
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 -
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 -
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) ?
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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) -
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??
0-30 Vdc Stabilized Power Supply
in Projects Q/A
Posted
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.