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| Simple DIY Linear PSU |
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| xavier60:
--- Quote from: panoss on March 07, 2020, 08:32:51 am ---RL=10 Ohm, Q1 Vb= 7.12V Ic=0A RL=5 Ohm, Q1 Vb= 7.60V Ic=0A No current through Q1?? :-// --- End quote --- Q1's Collector current should be the same as the current through R10 witch can be calculated from its voltage drop. I would also expect the op-amps to be allowing Q1's Base voltage to go up much closer to 9V. Check this. Without knowing the current gain of the output transistors, I can't work out the expected maximum output current. You can try lower values for R10 as a temporary fix. Watch for stability problems. |
| kallek:
That .pdf file does not open. At least base current go through because voltage drop. Are you sure you are measuring dc current? |
| panoss:
kallek, the pdf file is not actually a pdf file but a pdsprj file: you have to change the .pdf to .pdsprj. Yes, I'm measuring DC. I changed the Amp Meter and now it shows current flow! (the other amp meter I used has a low resollution!!!): RL=10 Ohm, Q1 Vb= 7.12V Ic=0.00143A Ve=6.45V RL=5 Ohm, Q1 Vb= 7.60V Ic=0.00189A Ve=6.9V |
| panoss:
--- Quote from: xavier60 on March 07, 2020, 08:47:54 am ---Q1's Collector current should be the same as the current through R10 --- End quote --- RL=5 Ohm, Q1: Ic=0A 0.00189A IR10=0.00190A |
| kallek:
No I did not. I assume that then I need Proteus too. Currents looks like ok, the difference is probably base current. Next measure Q2 current to check if pass transistors get enough base current. |
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