Jump to content
Electronics-Lab.com Community

wuemura

Members
  • Content Count

    151
  • Joined

  • Last visited

    Never
  1. Hi audioguru, I've checked and re-checked the new connections but some how made the opamp's to oscilate, pins 5, 6, 9, 10, 12, 13 has a clear beep on it and the output also. The power amp blocks had a small "buzz", removing the supply jumper away from the input pins solve this issue. No problem, i will rebuild it. Thanks
  2. Hi audioguru, I've changed everything values, tracks etc. When all is ready and i turn it on i could not hear any music at all, but, i could hear a clear, loud, no noise or distortion 1Khz beep ;D ;D ;D I will do this from ground zero all over again in separated boards, one for the main input signals and filters and other just for the TDA2005. Thanks, when is done i come back here to post the schematic.
  3. Hi Audioguru, I did some more tests with only one stage, all other stages are out, injecting signa at R36 with all the changes, the sound is like AM radio with noise and stuff, using a 470K in R68 and injecting sound there still the same, lot of noise with sound. Removing this opamp and injecting signal at the same place (R68) i got a cristal clear sound, changing the TL074 make no difference. Do you think it could be ground?? Or oscilation of the TDA2005??
  4. Something is wrong, i removed all the opamps and the TDA2005 output is quiet, but still if my hand is near the caps it generates alot of noise. If i touch the 2.200 caps i can hear radio.... I will do it all over again. Any sugestions that i should follow to do pcb layout and avoid this noise power amps have this problems?
  5. Hi audioguru, I've done the changes, but the circuit start to make sound like a fart ;D
  6. Hi audioguru! I will try your changes :D Thanks
  7. Hello guys! I want to use a mid-range and tweeter to make a center channel in my car, so i choose to use the TDA2005 plus an active crossover. When i turn the circuit on it has a static noise like, sound like a pink noise to me. So i remove R66/67/68/69 to isolate both circuits, analysing the filters all sound OK, conecting the speakers at the output, silence but looks like the circuit is too sensible if my hand is near, injecting RCA audio signal over C21/22/23/24 the speaker plays at full volume and no quality at all, there is this static noise with it, in small proportion but it was there
  8. Just passing by to upload the last changes, board design, if some one decide to build the project.
  9. Hi audioguru, it was a high resistence choke and was the cause of the problem. The LM317 only get burning hot when i set the NET-MD/Walkman to charge the battery because of the current to do it. I did not build this to charge nothing but is working, with a small heatsink it will not shutdown, the circuit can handle it fine, i can full charge the bateries without problems. Just playing MD or cassette it doesn't even get hot. Thank you.
  10. It was Ldanielrosa. Mine some times made the led REG flash like a HDD everytime the MD lenses was moving. I just remove the choque, add jumper and its working fine, the LM317 just get a bit hot, it will get burning hot when is chargin the MD player batteries.
  11. I've found the problem, it was the choke but without the choke i got engine noise, to solve that i add a 1R between the my board and the device. NET-MD and Walkman working fine!
  12. Hi audioguru, The walkman that i use is the old SONY WM-FX822, here there is a nice picture of it: http://www.geocities.jp/sony_transistor_radio/walkman/_index.html It works with one AA battery and gives a nice 8hrs non-stop playback (cassette) and a few days with radio. It uses only about 10ma to operate, about 200ma to work (cassette) and the worst case when you do a reverse is about 368ma. The LM317T is rated to handle 1.5A right?
  13. I never use the LM317 and this was the first time, i have a NET-MD and old Walkman(cassette) that i want to use in my car, the NET-MD uses 3.0V and the walkman 1.5V, they need about 200ma to work. The thing that i've noticed is that the output of the regulator oscilates too much, at first i calculated Vout to be 3.05VDC but the voltage drop at use was 2.98VDC, so i recalculate the values to give a 3.20VDC (3.23VDC). The regulator is a LM317T(1.5A) and dont know why it can't handle this devices, the walkman works fine with radio, but do not work with cassette, when the motor start to run the
  14. I don't think that this sound stupid. It needs AC because is the principle of his work. I think that this solution comes with a complete package, not just the swing motor, if some one get only the swing motor, without the controlers, this sound stupid to me because it's the same if you buy a chevy car engine to adapt in a Volkswagen Beetle without the central unit, electronic sensors etc, and say "it just need fuel to work. I was googling around and have found that this swing motor is used by some car manufactures in a eletric air conditioner, the principle is the same, but you will not conn
  15. At the link they say: Principle When an AC current is applied to a coil placed at right angle to the magnetic field, a thrust occurs according to Fleming's left hand rule. This thrust is directly applied to the piston, which then performs the compression and intake cycles. If this swing motor works with AC, read this at the same page: http://www.sawafuji.co.jp/english/tech/dd.html In DC-DC converter, a DC voltage is first converted to an AC voltage using semiconductors, the resulting AC voltage is changed to a certain AC voltage with a transformer, which is then converted to a required DC
×
  • Create New...