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jon

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Everything posted by jon

  1. And I want to know, does it change something if I connected all the transistors' collectors together and then to +9V and all the three bases together to the 4.7 K connected to the ground and a wire going to pin 7 of the dual opamp? J.
  2. Without the mic connected, voltage of pin 5 varies between 0 V and 5 V and there's no current on pin 6. But everything is connected well. I just don't get it... J.
  3. I did the circuit again, but now all the LEDs are working together and when I tap on the electret mic, the LEDs seem to react inversely, meaning that the LEDs turn off when I tap on the mic. (And it's really not as sensitive as it was when it was working well...) I verified the circuit three times and I found no problems, but I don't know why it isn't working. J.
  4. OK but the datasheet shows how to cascade two LM3915 in Dot Mode, does that mean the I can't change the mode to bar after? And if I cascade two LM3915, can I still use the 9V battery or should I change it with something with a higher value? I think I'll just keep it like it is for now... J.
  5. And I want to know, if I add one or two other LM3915, how would I connected them to let them work properly and extend the range? And should I not include the AGC-based dual range (and where is it?) if I decide to add more LM3915? J.
  6. Yes I did all those things, but I think the problem is on my weldings, maybe I connected some wires not correct or I connected some wires that should not be connected together, I don't know. I'll check them... J.
  7. I don't know, that's the problem... There's too many weldings... J.
  8. Do you think there might be any problem on your Veroboard schematic? Because it doesn't work... J.
  9. Why is there an arrow-like thing on the (9,17) point? And what does it mean? J.
  10. Ah ok! Now I understand why LEDs connected to pin 1 were always lighting... Thanks, J.
  11. Where is R18 on the Veroboard circuit? J.
  12. Thanks for everything! Everything is working fine till now! (and I hope not to have any more problems, and if I do I'll need more of your help...) But now I just have to understand your Veroboard drawing so I can reproduce it and finalize it all... Thanks again AudioGuru! J.
  13. Ok, but I think the range of this Sound Level Indicator is between 15 dB and 45 dB because a pin dropped at one meter is 15 dB and the LEDs react to it. It even detects someone walking five meters away in another room, with the door of my room closed! And yes, all the LEDs light and turn off when the battery is week, I verified it. I think I can change the amplification by reducing the value of R5 or R8. J.
  14. The Sound Level Meter works! The only problem is that it's too sensible, I don't think it's range is 45 dB to 95 dB, all the LEDs are reacting for all and every sound. Is there a way to reduce the amplification? And the other little problem is that LEDs connected to pin 1, 2 and sometimes 3 and 4 on the LM3915 are working all the time, even when there's no signal... Oh and the voltage of pin 5 when there's no signal is 0.04V and pin 6 is 0.5V. J.
  15. Ok, I just completed the circuit another time. Now the LEDs seems to be reacting to the electret mic, but in another hand it works even when I remove the mic... The LEDs are lighting all at once and then they gradually stop and then gradually works, and it does that all time, none stop... I just don't understand what might be the problem... I'll continue checking it. J. (And I'll soon have the voltages...)
  16. Ok. What's shielded audio cable? And what's the use of it? J.
  17. Yes I used those things but I think the current is not passing through them, that's why maybe all the LEDs are working at the same time. J.
  18. I replaced the dual opamp but it didn't change a thing, one the LEDs works all at once or nothing works and the battery gets hot. I'm still trying to get the voltages... J.
  19. Ok, but I can't measure the voltages now, I'll give them when I'll have them. And the R15 is connected to the +5V but nothing happens. J.
  20. Ok now, does that mean that R1, R2, R15 and C3 are connected on the line of the LM2931's output (so the +5V)? If yes then I tried it but it does not work... J.
  21. OK thanks! I'm going to reverify it all! And I'll come back if necessary... J.
  22. Ok I'll check the voltage for the pins. And maybe the problem is in the transistors' connection. Where do I connect the + of Q1 and Q3, on the +9V or the +5V? And another thing, I connected the LM2931AZ-5.0 on the same line as the LEDs, so do I have to supply it with current with the +9V? The same thing with the 10/1W resistor. I'm going to check it... (Another question, what does all the red X's on your Veroboard layout means?) J.
  23. I don't think I substituted any parts. When I plug the battery to the circuit every LED works (even when there's no signal...) except the ones connected to the 10th pin on the LM3915. I looked around and I think it's maybe because of the 3rd pin of the LM3915 connected directly to the +9V, because when I take it off no LED works. The brightness pot and the mode switch works fine, but when I turn the brightness pot to the max some LEDs stop working (even when there's no signal...) I think that there's no current passing after the LEDs and I don't know why... Thanks, J. (Is there any e-mail to contact you, because I have to finish this project fast and you only seems to check this forum twice a day and I really need your help)
  24. Thanks for the image, it's a bit better, and now I'm done with the circuit but when I supply it with current every LED lights and there's no sound around! What might be the problem? (And what's the order for the LEDs, is it 10 to 18 on the LM2915 or is it 18 to 10?) J.
  25. Thanks for the answer, but do you have a bigger and cleaner image of the circuit you used? Because I can't see well on the image you provide on the site. J.
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