Discussion in 'General Electronics Chat' started by MusicTech, Jun 7, 2008.

  1. MusicTech

    Thread Starter Active Member

    Apr 4, 2008

    I was just looking at that page and wondering, is it possible to attach a radioshack speaker to that ( and have it play the frequency? So then my other question is, what is the formula for time it takes an inductor to charge. I suppose I would have to find some of my more massive resistors to do this in an audible range, as all of capacitors are in picofarads... very low picofarads
  2. SgtWookie


    Jul 17, 2007
    Well, that's a passive tank circuit; just an inductor and a capacitor. More than that, it's a theoretically ideal tank circuit. The interconnecting wires have a resistance of zero, as does the capacitor and the inductor.

    Real-world components have at least SOME resistance, however small. The resistance causes a dampening effect on the oscillating circuit, and the oscillations become smaller and smaller until there is no signal left.

    Active components, like that 555 timer you have, work with passive components to provide reasonably stable output signal levels.

    Without active components driving them, the passive components won't keep a signal going very long at all.
  3. MusicTech

    Thread Starter Active Member

    Apr 4, 2008
    So the chip will be able to have the active battery in the circuit without having 1 state, correct? Just out of curiosity, how long would it continue to output for? Is it even worth trying, or would it be so quick that you wouldn't have time to see it?
  4. Audioguru

    New Member

    Dec 20, 2007
    The "speaker" is very cheap, small and has low quality. It might last if you limit the power fed to it to almost zero. Its small zize limits its sound to low volume clicks and beeps. Music or voice will sound like low volume only high frequencies.

    A 555 oscillator can feed the speaker if a series resistor is used to limit the power.