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  1. R

    0-30V Stabilized Power Supply

    About a month ago I asked if anyone could explain why my 30V 5A (with 3 x TIP3055 output transistors) suddenly failed at 45V and no current.  Both Audioguru and Redwire (I think) suggested a short in one of the 3055s.  Finally I have isolated the fault to a 'popped' 3055. At the time that the PS...
  2. R

    0-30V Stabilized Power Supply

    Earthing matter sorted thanks. Next question:  our DIYFAN option shows a 24V Zener and resistor across input +ve and -ve to provide a stable 24V supply voltage to pin 7 of U1.  Remove the connection of pin 7 to +ve. Since the +ve input voltage can drop at high loads, what do you think of this idea?
  3. R

    0-30V Stabilized Power Supply

    Thank you for the helpful response. I am not sure what you mean by 'electrical outlets that were wired backwards'.  In Australia mains outlets have three wires - live, neutral and ground/earth (for earth leakage protection).  Would you recommend that I simply do not connect the earth to the...
  4. R

    0-30V Stabilized Power Supply

    I have two questions: 1) can the circuitry associated with RV1 be omitted?  What would be the consequence? 2) when mounting in a metal box with the chassis earthed to mains earth (green/yellow), should the -ve on the electronics also be connected to mains earth?
  5. R

    0-30V Stabilized Power Supply

    Hi liquibyte I have been involved in this project for nearly two years.  I built the Picmaster version from March 09 and it worked fine for a while.  Recently while charging a 34Ah battery the power supply failed - voltage went to 42V and zero current.  What do you suspect has blown?
  6. R

    0-30V Stabilized Power Supply

    Hi mate Thanks for the idea, but already changed to 56ohm with no effect.  I suspect that there is something wrong somewhere but cannot find it.
  7. R

    0-30V Stabilized Power Supply

    Audioguru/Redwire - thank you both for all the input and help.  While trying to make further voltage measurements on the pcb I managed to blow up the regulator circuit, and have now had to replace the 10V zener, Q3, and LED. The PS now operates as before, without the 'dimming' of the LED at high...
  8. R

    0-30V Stabilized Power Supply

    Hi Mendimano It is amazing how closely our projects look in the end.  Thanks for the photos. I have invested too much time (and money) to give up now, so hopefully with the help of others it will get finished and work according to expectations. Regards
  9. R

    0-30V Stabilized Power Supply

    Great help, guys.  I am trying as fast as I can to check your suggestions.  Since the last thread has raised the topic of maximum supply voltages, can you help on this? 1) the supply transformer has input 220V and 240V, and output 0-24V or 0-30V.  a) When I use 220V (and Australia is 240V off...
  10. R

    0-30V Stabilized Power Supply

    Hi Redwire My mistake, the power transisters are TIP3055 in TO-218 configuration. Thank you for the input regarding the input offset question.  For some reason, I have +1.6v wherever others have +1.41V and I wonder whether this could be causing the problem.  I was unable to get R7 at 0.27ohm...
  11. R

    0-30V Stabilized Power Supply

    Thanks Audioguru, I will buy some replacement TLE2141s and see whether this fixes the problem, but I have my doubts, since I have tried moving them around with no change in results.  I have also discovered that the input offset pot RV1 has no impact on any of the readings - does this tell us...
  12. R

    0-30V Stabilized Power Supply

    More pics
  13. R

    0-30V Stabilized Power Supply

    Hi AudioGuru Finally the project is near completion - pics attached.  Thank you for the help getting to this stage. I have two problems: 1) The current limiting circuit does not function correctly and I need some help with trouble shooting.  With P2 turned down to about 1kohm (near minimum) the...
  14. R

    0-30V Stabilized Power Supply

    Hi Audioguru I have had a lot of trouble sourcing the shunt resistor (0R27 ohm) for the 5A version in Australia, nearest is 0R22, 10W, or 0R33 10W. But in the process I think I have ordered the wrong digital voltmeters (0 - 99V 3 wire) for the current display.  Since the volt drop across the...
  15. R

    0-30V Stabilized Power Supply

    Hi guys I have trawled through the 123 pages about this project on the first listed subject, and then the 96 pages in this listed project, and I note some confusion and some frustration, so I have spent time trying to filter out a solution for the newcomers to get started and to have success -...
  16. R

    0-30 Vdc Stabilized Power Supply

    Hi Audioguru Seems like you have been on this project for some time, and getting a bit frustrated that you have to repeat the same information endlessly - I understand, but I am now new to this project and looking forward to constructing the psu according to the latest version. I have your bill...
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