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bugmenot's Achievements


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  1. I'll change the 3 TLE2141, the BD139 and the 3 2N3055 for new ones (and put R17 the original value 33R). I want this PSU to work better than my old (fixed) version (3A). I don't like the way the PSU (Redwire 5A) is working now... the old (fixed) version I build is working better than this one... :-\ I hope with the changes it will work better than my old PSU... :'( And after I change the components
  2. And the PSU don't reach zero volts... Can I make any modifications in R10 or in RV1 to make the 0V adjust reach zero?
  3. Ok, I know. I don't change the opamps. It's the same TLE2141. What about the R17 increase changes? It's ok? When I calibrate the LCD meter it's show the correct current load of the same 120mm PC fan (0,23A), but when the calibration finish the meter shows 0,13A only. :'(
  4. For now I only have 6 OPA445 opamps... No more TLE2141 :'(. (Samples from TI) The film capacitor you are talking are polyester film type? If I increase R17 value I will solve the led on problem in the current pot set to minimum? And the current LCD meter shows less current than the multimeter shows when I power 1 120mm PC Fan 12V 0,33A (The multimeter shows constant 0,23A and the LCD meter shows 0,14A. The R7 is two 0,47R 10W in paralel (0,235R = 0,24R?).
  5. Hi AudioGuru, R17 is 33 ohms and is connected at the lowest voltage pin of the current-setting pot. But I measure the voltages enter -C1 point (0V) and pin 3 of U3 (wiper connection in current POT): 8,3mV (current pot set to minimum and led on); 12mV (current pot set to led off). When the led is off the output is 21,4mV (zero adjust trimpot set to minimum). In this test I used only 2 2N3055, to have access to the PCB and make the measurements.
  6. I use the TLE2141 too. I'll measure the voltage in input of U3. The schematics I have is the november/09 version. I put the parts in the part list. The meters are oscilating I think is because the input voltage for the LCD meter are above 35V, the limit for the 12V regulator. I put a 22R resistor in series and it don't oscilate more. I have the previous version of the PSU (3A) and it adjust the zero and the current pot in the minimum don't light the led.
  7. And the voltage and current in the LCD meter are oscilating... :( :-\ ???
  8. I have problems with my PSU (Redwire 5A version). I used 3 2N3055, two 0,47R 10W (it's the only I got) for R7, two 10.000uF caps for C1. The voltage pot works good, but the current pot in the minimum setting, without load, lights the led. And the zero volt regulation trimpot don't adjust to zero. Can anyone help me? Regards.
  9. Hehehe, I had the same pot problem... :) usually I put the wiper in the center in the PCB, but I build the PSU and it don't work, then I change the pots wiper position and it's seemingly looks ok now... I'll test a little bit more... :) Thanks notedly to AudioGuru and Redwire for the support. Thanks to all who comment in my previous posts: hero999, erivanst, and others. I'll post some pictures soon.
  10. AudioGuru, I'm building the 5A version. therefore is the reason I want to put 3 or up to 4x 2N3055. The measurements of Hfe of the four 2N3055 with the results of 159-180 Hfe where got under 2,5mA of current in the Hfe test. Under 1,5A of course the Hfe will be lower. But I don't know to make this conversion to have the results for the Hfe (159-180 Hfe - 2,5mA) under 1,5A. I attached the SC Analyser 2005 project for information only. SC_Analyser_2005.pdf
  11. Hi AudioGuru, I see the datasheet values for the transistores. With the "SC Analyser 2005", a Elektor Project, I read the Hfe of my 4 2N3055 and they are in the range of 159-180 Hfe under 2,5mA current test. It's right? Can you guide me to the right results to know if the redwire circuit will support 4x2N3055? Thanks for your support too. Erivanst, do you find the Atmega8 smd version for the LCD Multimeter?
  12. Ok, so we can safety have a max 5A continuous current draw output (6A intermitent)? Still I can use 4 2N3055 (5-6A output)?
  13. So how much is the max output Amps with the components i told? Without damage the BD139 or U2? Still i can use 4x2N3055? I have to regulate the max current safety to how much amps? Regards Audioguru. please guide me to get the best of the PSU with the parts I have.
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