T
Tim Shoppa
- Jan 1, 1970
- 0
Is there a general theory of locking simple (two-transistor or two-
tube or two-whatever) RC multivibrators to a sine wave or square wave
reference? Especially when frequency multiplication or division is
done in the process?
What I'm thinking, is that someone must've worked out some theory that
says if you have a multivibrator of a certain natural frequency, and
that if you inject a sine wave of a given amplitude at a base or a
cathode or whatever with a slightly different frequency, that you will
be able to lock if the natural frequency is 10% high or 5% or low or
whatever, and if the amplitude injected is bigger, then the lock range
is bigger, etc.
I'm using some very vague terms above. I've explored the topic using
Spice and clearly there's some more general math rather than "run a
metric buttload of Spice simulations" because there are obvious
patterns in the regions of stability. The patterns are kind of pretty
when you are locking to a harmonic or subharmonic.
But rather than running a metric buttload of Spice simulations, I
believe there must be a more general theory about amplitude of
injected reference and range of lock.
Maybe this is some class of PLL with very broad/nonexistent loop
filter.
My old-fashioned references that talk about phase locking
multivibrators, or phantastatrons, like the MIT Radiation Lab books,
give some general guidance but not really the formulas I believe must
exist.
Any clues for me?
Tim.
tube or two-whatever) RC multivibrators to a sine wave or square wave
reference? Especially when frequency multiplication or division is
done in the process?
What I'm thinking, is that someone must've worked out some theory that
says if you have a multivibrator of a certain natural frequency, and
that if you inject a sine wave of a given amplitude at a base or a
cathode or whatever with a slightly different frequency, that you will
be able to lock if the natural frequency is 10% high or 5% or low or
whatever, and if the amplitude injected is bigger, then the lock range
is bigger, etc.
I'm using some very vague terms above. I've explored the topic using
Spice and clearly there's some more general math rather than "run a
metric buttload of Spice simulations" because there are obvious
patterns in the regions of stability. The patterns are kind of pretty
when you are locking to a harmonic or subharmonic.
But rather than running a metric buttload of Spice simulations, I
believe there must be a more general theory about amplitude of
injected reference and range of lock.
Maybe this is some class of PLL with very broad/nonexistent loop
filter.
My old-fashioned references that talk about phase locking
multivibrators, or phantastatrons, like the MIT Radiation Lab books,
give some general guidance but not really the formulas I believe must
exist.
Any clues for me?
Tim.