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  1. A

    fm transmitter scematic required

    The Micromitter has flea power. Only -10dBm out of the chip. To get 1W you will need to amplify at least 40dB and deal with the resulting harmonics! :)
  2. A

    Got a couple questions regarding this fm transmitter

    RF feedback is known to cause "hum". This is normally not a problem when the transmitter is mounted in a metal box and screened audio cables are used. Kits that comes with plastic boxes may have this problem.
  3. A

    NEED HELP IN A BAD WAY.... LED PROJECT

    Also there will be a problem to turn off the scr's when the count restarts.
  4. A

    NEED HELP IN A BAD WAY.... LED PROJECT

    I don't know about a single chip apart from a micro. Discrete it could be done with a row of D-type flip-flops wired as serial-in-serial-out (SISO) shift register and clocked by the 555. You may also use 2X 8bit shift register chips with the proper feedback after 10 stages.
  5. A

    Cross

    Looks possible to do with only 1 comp and 1 opamp
  6. A

    3 Legged 5600uf cap

    Extra leg may also be for mechanical strength when mounted in a pcb and not connected to anything internally. Few simple measurements will be all that is needed to solve the mystery.
  7. A

    3 Legged 5600uf cap

    You used to get split capacitors (2 caps with one common neg terminal) used in older TV applications, although I have not seen them for quite some time.
  8. A

    Inductor in LC filter

    Maybe we should define "very high frequency"
  9. A

    Automatic Light System

    Here in the US it is quite common. You buy these inserts and install them into a normal light switch box. It has 3 positions; off-auto-on. The circuit has a sensor to sense movement inside the room and the whole thing costs about $6 and takes about 3 minutes to install.
  10. A

    Inductor in LC filter

    There's LC filters of all kinds, low/high frequency and of various power levels. For example, you won't use toroid at very high frequencies because of the losses. Each applicarion will require its own selection.
  11. A

    Cross

    Are the waves separate like on 2 inputs or combined at some point?
  12. A

    Cross

    Will the phase shift always be the same or variable?
  13. A

    electronic stesthoscope

    Souns like a easy task for a PIC micro. Look on the microchip website for typical counting applications and code to drive the displays. You will also find a lot on Google.
  14. A

    Spilled beer on roland vs-1680, any suggestions??

    What I have done in the past is to wash equipment that had coffee, coke
  15. A

    please help me .

    http://www.anatekcorp.com/qdmmvom.htm
  16. A

    LG TV not powering on

    Often these TV's have a switching type PSU. They use a high value start-up resistor to get the PSU control circuit going. After that DC gets fed back through a diode blocking circuit to supply the control part of the PSU. Over time these resistors increase in value and have problems supplying...
  17. A

    RC phase shift

    The document also states that the lowest fundamental crystal available is about 1kHz!
  18. A

    RC phase shift

    Low frequency crystals do exist and are used as shown in the table
  19. A

    Highside mosfet gate spike

    Introduce some dead-time in your switching
  20. A

    transmission lines

    That you can calculate from the well known formula wl=speed of wave/frequency wl = full wavelength in m speed = 3 X 10 ^8 m/s frequency of operation in Hz
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