Recent content by Tedyp

  1. Tedyp

    Help: White - Pink Noise Generator

    :D LOL, No Staigen, it's nothing secret here :D , it's just I'm too lazy to turn on my third PC where I have installed the Orcad (yes, legal :) )and begin to "draw". I use it on more complex projects, but this one, just to spite, small and simple, I cannot find the root of the problem ... ...
  2. Tedyp

    Help: White - Pink Noise Generator

    Thank you Staigen, I've changed the coupling caps first to disk caps, and noticed no improvement. I've changed them to Tantalum caps - almost no change. I don't know if there is an acoustic or magnetic feedback (I cannot put a resistor load instead of the speaker, as then I'll put off both...
  3. Tedyp

    Help: White - Pink Noise Generator

    Hi Staigen, All my decoupling caps are NP0 - do you thing that changing them to disk caps may have such an influence on the circuit that it may stop to oscillate ? I'll give it a try, no problem, if you think so. Regards, Tedy
  4. Tedyp

    Need: Ferrite SLUGS - please read

    Thaks for responding rigdoctor99 I live in Israel, but I have friends all over the world, and I'm buying sometimes large (or small) quantities of components from all over the world, including UK and if there is any manufacturer or seller who sells such things, I see no problem for sending by...
  5. Tedyp

    Need: Ferrite SLUGS - please read

    Hi, I've tried for about a month to find ferrite slugs all over the internet - without result. I need about 1000 feritte slugs at 3.5 mm diameter - about 8-10mm length. I gave several from old TOKO coils, but I need to buy them ASAP, - and as I've mentioned - I cannot find any resources. Maybe...
  6. Tedyp

    Help: White - Pink Noise Generator

    I'm ashamed to tell.... :-[ :-[ :-[ At least I found the reason of the oscillations: The LM386 works OK, but as I'm using as a speaker a small tweeter, I haven't noticed that as soon as I put it near the PCB, no matter where – I got some kind of "microphony" feedback. This tweeter is enclosed...
  7. Tedyp

    Project: Voltage tester for BT line

    Usually, at most (99.9) of the  telephone exchanges, the earth (ground) is +. If you try to measure between 2 points with the same potential - the led won't glow. It'll glow only from one leg to earth.
  8. Tedyp

    Help: White - Pink Noise Generator

    I've found that the main problem is that the LM386 oscillates at 9V - no matter which and how many decouping CAPs I put and if there is an input signal or not. Again, it's built on a PCB, not on VERO board. Any idea what to do to stop it oscillating? I'm getting a very nice sinus at output, but...
  9. Tedyp

    Help: White - Pink Noise Generator

    Thank you audioguru, Yes, I've tried Zener diodes from 2.7 to 12V - no noise at all. I've tried it with a very stabilized P.S. Dead as a rock !!! Between 2.7V to 4 V works like a charm. The interesting part is that at 9V, I could hear and see on my ocilloscope the noise the reversed bias...
  10. Tedyp

    Help!!!

    Hi, You can use any type of LED, not only IR but a regular one as well, in case that the device is in dark. You can place ANY led on one side of the "tube" you r ysing for the coins, and a light sensitive cell on the other side, and it'll work ok. A suitable motor: you may buy or get an old...
  11. Tedyp

    Help: White - Pink Noise Generator

    Hello all. I need to build a "pink noise generator" or a "white noise generator", using as final stage an LM386 and a speaker. It has to work from a 9V battery I've tried 2 configurations for the "white": 1. The "open collector transistor" as a noise source (base = gnd, emitter via a 470k to...
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