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noworries2004

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Everything posted by noworries2004

  1. Fantastic news got newmc34071 yesterday and the circuit works perfectly, Found problem in other circuit, pin 4 of U3 was 20V, 187ohms between pin 7 and 4 so chip blown, Working perfectly now, Thanks a million for your help everyone especially Audioguru and Redwire.
  2. Just found the main problem i think, 0.33 ohm resistor were connected to the base, So therefore that would explain the high output all over the circuit.
  3. Ok thanks audioguru for your help yet again, I will try and get the mc34071 opamps, and i will get the r7 resistor will let ye know how i get on
  4. Ok starting again with a fresh PCB. All components have correct value double checked all resistors with ohm meter. How ever i am missing 34071 Opamps. The only available opamps are 741 opamps. Is it ok to use these instead? Also i dont have .47ohm (R7) resistos. Will it be ok to leave this out and forget about the current limiting. Is it ok to put in a piece of wire instead? Also any more suggestions. My problem with the last PCB was that i had it on aero board and when i first plugged it in a couple of components smoked. (R7 and U2). Can i test this circuit with a dc power supply first before i plug in the transformer, bridge rectifier. Thanks for all your help. Regards
  5. This is my power supply connected to the bridge rectifier D4 is connected to the pin opposite the rest which connects to r1 and c1, R1 is correct 2.2K, the rest of the parts im possitive are correct,
  6. Just changed the wiper on the 2 pots, prob still there but U2 not heating up as fast Quick question, Think R7 (0.47ohm ) is blown, disconnected it from the circuit and it is measuring 26Kohms, dont have a replacement, is there any other resistor that i could put in. I am measuring all my voltages with the neg lead of voltmeter at the - sign between r7 and c7 on the schematic is this correct is this ground ? Cheers
  7. \Audioguru following reststances were taken between collector, base emmitter collector - base 0L Base - emmitter 0L Collector - emitter 2.341 M Ohms
  8. Please find the enclosed pics of my project, problem still exists
  9. I have checked the power transistors but i am still getting 41v at the output, I used a single power transistor but still no joy, How can i check if the power transistors are blown?
  10. Thanks audio guru i will recheck the pins of the output transistors, and ill let you know how i got on, yes it is the latest parts list + Schematic Cheers
  11. Current limiting LED is always on, U2 heats up as well ,
  12. Finally connected up m ypower supply unfortunately it is not working, Measuring from Ground, using a 29.4 volt transformer 4 A. I am getting an input to R1 of 41V, how ever i am also getting this 41V at the output, Measuring voltage pot, i am getting a range from 1.1V up to 10.86V. I am reading 1.082 V across R5+R6, 0.541 across R5. Some how the input voltage is going straight through to the output? Has anyone got any ideas or suggestions. Email me back for further information. I am using th PCB recieved from Red wire so that is definetly ok. Cheers Really need some help guys
  13. Thanks Audio guru, With regards Q1 from last comment would this graph be a fair reflection of what happens when current regulation kicks in?
  14. HI I am currently constructing the updated version of this power supply, I have a fwe questions about this power supply. Q1 ; What happens when current limiting kicks in, does the output voltage drop or does it stay steady. If current limiting is then does this mean that the power supply is a constant current source rather than power supply. Q2 ; What is the output regualation of my power supply. Input transformer is 31.6 V AC. Also what is the rated load of this power supply. Thanks for your time especially redwire and audioguru. Cheers
  15. HI Does anyone have a copy of the PCB layout please?
  16. Hi i have setup the up to date circuirt schematic, I am using a 31.61VAc transformer. However my U2 just went up in smoke, I have everything wired correctly as far as i know. Did anyone have similar problem, Also i think my R7 smoked too. Any one got any ideas on what maybe causing the sizzling effect. Cheers
  17. Cheers for that Audio Guru. Also just wondering for C1. I got a 6800uF 63V Cap instead of 12,000 V63V. Would this work as well or will i have to order another cap?
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