Recent content by kebloks

  1. K

    considerations in replacing transistors???

    what parameters do I need consider in replacing transistors? my idea... please tell me if i'm wrong Vceo must be greater than or equal than the original. Ic must be greater than or equal than the original Power dissipation must be greater than or equal than the original. Frequency range -- no...
  2. K

    Cutoff frequency and 3dB points

    At -3dB the output power is half the midband power output. ( Yes it's noticable )
  3. K

    Quick questions about transformers

    I found a site for calculating filter capacitor values... http://my.integritynet.com.au/purdic/power1.html If we accept the 2.5% ripple as adequate for our purposes then at 13V this becomes 13 * 0.025 = 0.325 Vrms.  The peak to peak value is 2.828 times this value. Vrip = 0.325V X 2.828 = 0.92...
  4. K

    Cutoff frequency and 3dB points

    In the Bode plot: Cutoff frequency ( lower or upper ) are the frequency wherein the midrange gain is 3dB less.
  5. K

    Quick questions about transformers

    I just bought a transformer; multi-tapped 0-6-12-24, 12 Amp. Does it mean it can go up to the max 24 volts rms - 12 Amp ??? What's the min filter capactior value if used as a dc power supply? ( big capactors are expensive >.< ) Some transformers are rated in VA, what does it mean?
  6. K

    Comment about this design...

    Will it work for 3A? and... ( from the site ) "NOTE: &nbspR2 is determined by the voltage across the 220 uF Cap.         (Volts - 1.2) R2 = -------------           .015 Any Resistor close to the calculated value should be fine. Its only purpose is for an approximate 15 mA current...
  7. K

    Comment about this design...

    http://www3.telus.net/chemelec/Projects/Power-Supply/Power-Supply.htm schematics: will it work?
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