PLL tracking issues
kiat, Sat Jan 29 2011, 11:04AMhello.
I just built a PLL SSTC driver at
. I tested it out with a 330khz secondary (has small topload attached), and ran it off a fullbridge at 20v, 3a, 10 primary turns. So I set the resistor/ cap values to 330pf, ~17k, ~30k (or around there), for a ~260-~350khz tracking range, and turned the 10k vco pot from 0-10k ohm. The waveform of bridge voltage and sec. base current was in phase when the pot was around the middle. However, if i put my hand near the sec coil to detune it, the antenna does not track the fres and the driving frequency is the same. So the waveform rings and the output spark is gone (barely achieving breakout at 20v). Also, when the antenna is too close to the secondary the same thing happens, and at higher powers the antenna has corona on it and burns the wooden antenna support.
So, what am i doing wrong? I can post scope shots if needed.
kiat
Re: PLL tracking issues
Gregory, Sun Jan 30 2011, 03:24AM
The PLL will track the frequency, but not if this pass the max and min frequency setted in the PLL!
Gregory, Sun Jan 30 2011, 03:24AM
The PLL will track the frequency, but not if this pass the max and min frequency setted in the PLL!
Re: PLL tracking issues
kiat, Sun Jan 30 2011, 04:06AM
it IS in the min - max range, the point is that it doesn't even track the frequency even a little bit. Im nowhere near the ends of the tracking ranges.
kiat, Sun Jan 30 2011, 04:06AM
it IS in the min - max range, the point is that it doesn't even track the frequency even a little bit. Im nowhere near the ends of the tracking ranges.
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