Ronnie Walker (aka gpssonar) Replication

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Sebosfato, no.

This opamp is acting as a comparator.

Google this "opamp as comparator"

The 5V pullup line forces the opamp to be referenced at this level, and the output will feed the signal back to PLL ONLY WHEN IT RISES ABOVE THIS 5V LEVEL.

Out of resonance condition will cancel the flux of the entire core, and feedback will stay very low until "resonance" is achieved.

Anyone got the PDF patent (canadian) about tube cell resonant cavity? i have some words to quote and i lost my files.

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well basicaly is what i just said... it reduce the sensitivity of the circuit ...

this opamp i used lm 318 is actually 4mv sensitive so in its case is not exactly a comparator because the opapamp has a back to back diode inside look the small words on the datasheet

this made me change the circuit as i described... i use a 1kohm resistors in series with the inputs and i use a coil in series to get 90degrees dephased signal at the back to back diodes in the circuit that goes before the input resistors to get resonance to lock on high voltage  ...the other resistors are 1M feedback and 100k to ground...

the feedback coil and this coil in series form a closed circuit thru the back to back diodes with no resistors therebetween the 5 volt give a reference point so that the inputs wont suffer
the input resistor receives about 300mv from the back to back diodes...

its possible to use a capacitor  too but i have found that because of the reactances a coils is better to keep the resonance out of the feedback circuit


whithout this change it will work but will not lock well on the high voltage point .. will be aways bellow or above.... or not at all

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PLL is just a tool, it locks to the signal that is fed, like you and others know.

The trick is to provide conditions to feed only this signal when this condition occurs.

Sebosfato this is what i am talking about:
(http://www.circuitstoday.com/wp-content/uploads/2009/09/741-IC-Non-Inverting-Comparator-Circuit.jpg)

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right i think of this too

i have found that it locks at certain frequencies of the gate and at certain duty cycle... when gating of course..

the pll can follow a frequency.. .i used it to make a sweep changing a coil parameter... it follows briliantly

it maintain the circuit tuned at the highest possible voltage as you change the coils

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My thoughts is that is inverting instead of non-inverting one on the example.

It work also to "transform" the sine wave or half sine wave from feedback into perfect square wave due to the action of this two diodes,
and gives some gain.

PLL will see always the same signal amplitude, square  wave pulses of good quality.

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Bravo!

exactly that, the point is that one of the diode is constantly reversed biased by the 100kohm and 5v and ground.. this makes the opamp stay shut on low signal....

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here in attachment is one example of it... however instead of capacitors i use coils... the capacitors can be selected thru a switch or a resistor... but in my case coils work better

the capacitors are theoreticaly better at lower frequency... but will unavoidably become part of the resonant circuit,,,

again the 5v impeed anyhigh voltage to influx to the opamp...

you posted a 741 which is very slow for the task...

(http://www.ionizationx.com/index.php?action=dlattach;topic=3096.0;attach=14677)