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Old 08-21-2007, 01:54 PM
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Join Date: Jul 2004
Location: Rancho Sahuarita
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Does it also oscillate in phase if you disturb it slightly? It is possible to have the wrong or right loop gain for either speed or phase or both depending on how your algorithm works. In the circuit for the mechanical TV, a 4044 "type II" phase/frequency detector is used. While the type II 4044 phase detector is very linear for phase, it is nearly "bang-bang" for frequency, resulting in an oscillation when the speed is first pulling in, but then becoming very stable for small phase perturbations.
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