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Everything posted by Emiliano86

  1. hello...i have read all the comments adn i have some questions: 1- i want to design a pSU with 1.2-30V output at the maximun load possible, so what can i do to improve the ripple rejection?, more filter caps? 2- if the soulutio is to use more filer caps, i must use a bigger bridge, do not I? 3- if i use a 15 + 15 seconadary transformer, i can use only one side of it if i need a voltage in the ouput between 1.2 - 15V, and the two sides of the transformer if i need more than 15V, i think that it can improove the current output, but how can i do a voltage detector or selector or something like that?.... OK Thanks!!!! :)
  2. hi ante, The ripple appeared when I'd connected a load at maximun voltage that it gives (in my case 27V) and at 2.35 Amp, i know that it is very uncommon situation, it was only a test, ofcoures that without load it does'nt gives ripple. The solution is to connect a higer voltage transformer, change the opamp, and improove the filter, like said audiogoru, instead of using a 24VAC trafo, a 30VAC one (or 16 + 16), but in that case the opamp MUST be changed by other with a higer volt range . Good luck!!.. thanks audiogoru for your help!!!!....thank you ;)
  3. Pinky...i am planing to build this project, a regulated PSU with the LM317, i was searching on the net and i found a very similar regualtor the same voltage butinstead of 1.5 A, it can manage 3 A.......but bell I have some questions......for the LM317 PSU: 1 - if Iwant a 30VDC at maximun output, with 1.5A (very demandin), which is the transformer I need, because I have a 12 - 12 V 75VA?, or I have to use a 30 V one?... 2 - I am very intereting on the idea that you told at the beginig of the forum, that we can use a 12+12 transformer and a circuit to conect the 24V when i need more than 12.....but I can't find a circuit.... or something symilar, to have an idea.....Have you got a circuit or soemthing like that, or a croquis...??? 3 - another question I have is about the ripple.....how can I improve the filter section in the ciruit to make better the ripple rejection?.....is a good idea use a choke input filter?......please help me... 4 - may be the LM317 could be replaced by the lm350K....... Thank you very much!!!....and sorry for my bad english.......
  4. yes...but the problem is that it is imposible to find that OA in my country......I don't know what to do!!!!!!!...... I A M F R I E D!!!
  5. hi audiogoru!!......how are you?.....i am fighting with this PSU.....i could repair the current and voltage regualtor, i 've added two more 2n3055 transistors and it works fine.....it gives 3.25487 amps.....but the real bad thing apperared qhen i connected and test it in the osciloscope.........it was a desaster!!!!....the ripple is incredible!!!......and to get the thinsh wors it get to acsilate at maximun power 25VDC x 3.10amp...... I don't know ..... !!!!
  7. Audiogoru, I have a problem, when I turn on the Power Supply the output is constant at 29,8 VDC. My transformer is : 24 VAC - 75W The DC Voltage at the base of 2N3055 is 32 VDC I am using the TL081C OA The voltage at pin 6 of U2 is 27 VDC The voltage at the pin 3 of U2 is 9,3 VDC I don't know what to do. When I disconect the 2N3055 th PSU get normaly..... please help me!!!!! thanks.
  8. gonza.....why don't you try with the pcb pulicated on this web.....i used it and it worked!!!.......i'm doing some adjustments!.....but it works!!..... (i'm from argentina too!!)
  9. audiogoru!!...i need your help....i built this PSU...and he led voltmeter with the 7107.....but when i connect it with that PSU..it turns off.....i think that it could be because : 1- I have a 70 VAC at the output when i have 30 VDC.. to make the dual polariti supply I took 24VAC from the transformer and I rectifier and filtered, and there i connected the two regalutaros with some resistors... thanksss....
  10. hello, my name is Emiliano, and I have a problem with this circuit: "I've built the project -0 to 30 PSU-, and I decided to built this Voltmeter to conect it directly to the output from the PSU, but when i do that the Voltmeter turns off, I test the Voltmeter with another power and i worked.....I think that it could be because in te PSU project I have 70,02 V AC at max power (30,1 V DC)"...I don't know!!!......please if you can help me...... thankssss.........
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