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  1. RubicK

    0-30 Vdc Stabilized Power Supply

    Hi again! I have a problem with supply for my digital meters connected to this PSU. I have made a supply circuit for this meters. There is a diode bridge, capacitors (2x 100n + 100uF) and 78L09 stabilizator. This circuit is connected to output pins on transformer, where is 24V AC. Voltage on...
  2. RubicK

    0-30 Vdc Stabilized Power Supply

    Hi audioguru, I tryed it with DC motor and 100n across inputs of voltmeter - when motor is rotating slowly everything is well, but when rotations raise, voltmeter shows absurd numbers (It is a 3V DC motor. Bellow 2V everything is well but then voltmeter starts to show that voltage is about 8V...
  3. RubicK

    0-30 Vdc Stabilized Power Supply

    Thanks for you fast answer, audioguru. I have one more problem with my digital voltmeter. I think it is very sensitive. The range is 200mV and it is increased to 200V by a voltage divider. Sometimes it shows various numbers. For example when i touch with an unconected piece of wire on one output...
  4. RubicK

    0-30 Vdc Stabilized Power Supply

    Sorry, i have made a mistake :-//. This is not valid. Led doesnt light when no load is connected (so thats good).
  5. RubicK

    0-30 Vdc Stabilized Power Supply

    Hi all. I have just made this PSU. Everything works fine, but the current pot is regulating from about 0,02A to about 4,4A, but i want only 3A. Also when no load is connected and current pot is set to minimal current LED lights. I have some modifications on it. There are 2 paraller 2N3055...
  6. RubicK

    0-30V Power Supply - doesn't work

    I cannot download that image, it always downloads a 0 byte file.
  7. RubicK

    0-30V Power Supply - doesn't work

    I founded next 2 errors: R2 must be 82Ohms instead of 82k, and R17 must be 33Ohm instead of 33k!!! I hope that this errors couldn't damage any part on PCB...
  8. RubicK

    0-30V Power Supply - doesn't work

    Oh thats unbelievable! I have been bulding this supply according translated article: http://www.hw.cz/Teorie-a-praxe/Konstrukce/ART1438-Napajeci-zdroj-0-30V-s-regulovatelnym-proudem-2mA--3A.html Author of this text made a mistake in part list, he wrote that R3 is 220kOhm instead of 220 Ohm...
  9. RubicK

    0-30V Power Supply - doesn't work

    I have checked parts you have written, but i have nothing found. I am a beginner in electronics, so it is hard form me to find a mistake. I tryed to disconnect Q1 from the PCB. Voltage on output was about 30V but i couldn't regulate it. Can you also tell me what parts makes that 5,6V negative...
  10. RubicK

    0-30V Power Supply - doesn't work

    Hello, i have made this power supply and it doesn't work. When i turn it on, U2 is heating very much, current is around 100mA, potensiometers doesn't do anything, voltage on output is abou 0,2V. I have checked PCB and connection of each part, but i didn't found a mistake, please help i realy...
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