Friday, February 7, 2014

Phase Shift Std.

Unfortunately i can't tell if this feature is applicable in real since i don't have scope nor fq. counter to confirm signals over 48kHz (96ksps sound card) KYORITSU KM 2K (no good for small signal or i'm stupid to Z it up right for)

anyway i'm always interested in various oscillators so at the time i played around with LC loop back 1-s and found the next to be surprisingly effective


What i call a "Phase Shift Std." is the (L-C network) part (your) right of the amplifier stage, the "S" "o" networks at left are also important to fit the supply with desired frequency range (tough -- i have some lesser experience with that part)


as it can be seen it's not fully comprehended nor studied - i always do "heuristic" research or solving rather than analytical - you do calculus , apply result and . . . nothing happens - a complete waste of time if your concept doesn't already "tick" - this resonant network supports even very bad amplifier designs (such that have no power to push the ring oscillator formed of 'em) - the left hand side "S" of "So" may be discarded if the circuit is not to be run on low power or near it's components' transition fq.-s.

here's the ring oscillator v.


i mostly use such "Phase Shift Std." to evaluate the amplifier stage - ? the higgher the fq. it can be pushed at the better the concept for the stage



also related but not strictly under the scope of the title ::

here's a more simple way to link high fq. ring oscillator



such is just a test finds not any theory based - is just what seemed to start up best. At the time i was interested of how fast the transistors might be pushed to go

here's the above it's transition point the 2N3904 circuit



lately revisited 1.2V Quartz Oscillator circuit


the particular X-Tal Rs = 35 kΩ C0 = 2.5pF C1 = 4 fF Ls = 5907.105371 H Q = 3.47E+04 is tricky to get going with any std. circuit at that voltage - i haven't managed to get it going sharp at parallel resonance ... yet - so there's an idea to use whatever the fq. it's willing to go and PLL it up then correct the higher 1 by extracting adding pulses * at first attempts i likely attempted run (deviate) it with too much energy (so it didn't start up)

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