Purpose for variable choke in VIC

[Login to see usernames]

Presumably, in the VIC the choke is designed in such a way so as to completely limit current only to the point that the current doesn't pass the choke.  However, since the voltage is leading the current by 90*, the voltage still does leave the choke, even though the current does not.  There must be a zone where if the impedance of a choke is too high that the voltage does not pass or too low that current still does.  Is this the probable reason for the choke on the negative side (the current source) being variable?

TS

[Login to see usernames]

well, voltage doesn't really flow, its just the potential for current to flow. I would think that the higher the impedance the better, but i could be wrong.

[Login to see usernames]

I agree with that statement, namely voltage doesn't "flow", however its influence is apparently capable of being limited by resistance. If you put a bunch of lights in series, the first lights up and the rest in series gradually light up less due to voltage resistance.  However, if you string them in parallel, all the lights have equal voltage available to them and they all light up.

In the case of the inductor, the voltage wave advances when the magnetic field restrains the current.  The resistance of the inductor also reduces the available voltage, potentially to an unusable state.  It seems to me that chokes designed specifically to impede the current while permitting voltage is key to the effect (if this is even possible).

Quite frankly,  I'm beginning to wonder if the lower the impedance the better in the VIC.  If the impedance of the water capacitor is less than the impedance of the choke, the choke is going to try to force the current through the water capacitor.  However, if the impedance of the water capacitor is greater than that of the choke, it will resist that current and properly allow it to resonate with voltage.

TS

[Login to see usernames]

Hello TS_

Frankly ohms law is not that mystic. The example you gave about the lamps is not very real, they should all light up with same intensity if in series, the problem is that they are not exactly the same in real world and their resistances can even change with temperature. They all share the same current, the current times the resistance give the voltage across each lamp.

A choke creates what is called impedance. Impedance is the following: when you apply a voltage to a circuit having an inductor and the current start to flow it will develop a contrary voltage that in series with the applied one subtracts thereto the load will receive Vapplied - V across inductor. where the last is given by XL=2*pi*f*L and so V=XL*I.

Chokes are designed to block high frequency while allow low frequency to pass. A capacitor does the contrary it blocks low frequency while allo high frequency to pass. they are kind of filters. A microwave has two chokes between the source of current for the filament and the filament of the magnetron... given the freaking high frequency they are quite small.

A resonant choke blocks frequency only within a range, and its impedance is extremely high for the specific frequency. A resonant choke means a coil with a tuning capacitor in parallel with it.

If the capacitor and inductor has the same reactance, at a given frequency they are in resonance. the impedance of the circuit becomes zero. This mean that if you apply the Vt in series the circuit will behave like a resistor. Take a look at stan equations.  If you apply vt in parallel the impedance seeing by the source is maximum so the current will be minimum, however across the circuit the recirculating current is of greater value.


good luck

hope you understand what i mean

In my opinion the vic are made to drive a kind of parallel resonance... And the second choke migh have another purpose...

Another possibility is that stan used the inter-turn capacitance as resonance which is certainly parallel n regard of the source. once i got an incident where my pll tuned to this resonance in a transformer (was around 200khz) and the thing became light blue like a space ship i played with a bit but when i hit harder the thing blowed into fire. It was a toroidal core and the wire was steel that has a black plastic insulation, i couldn't find this wire anywhere again.

This would explain why he coupled the feedback into the transformer and not in an external coil.

[Login to see usernames]

Frankly ohms law is not that mystic. The example you gave about the lamps is not very real, they should all light up with same intensity if in series, the problem is that they are not exactly the same in real world and their resistances can even change with temperature. They all share the same current, the current times the resistance give the voltage across each lamp.

Quite frankly, put a string of 10  x 9V incandescent lights in series and then hook them up to a 9V battery and then come back and say that.  There is a cumulative resistance for each one in the series and end effect will be the the next in series will be dimmer than the previous until the rest do not light at all.  This was demonstrated to me the first time in grade 4 science class (primary school).    I have proved this with my own experiments.

Chokes are designed to block high frequency while allow low frequency to pass. A capacitor does the contrary it blocks low frequency while allo high frequency to pass. they are kind of filters. A microwave has two chokes between the source of current for the filament and the filament of the magnetron... given the *  high frequency they are quite small.

A resonant choke blocks frequency only within a range, and its impedance is extremely high for the specific frequency. A resonant choke means a coil with a tuning capacitor in parallel with it.

Band pass and band stop filters are designed to do what you have described here and require both a capacitor and an inductor either in series or in parallel depending on the application.


TS

[Login to see usernames]

About the lights string this fact is new to me. I still strongly believe is only about contact resistances and non equal share of temperatures. If it do behave as you described, those close to ground are dimmed? How do you explain that? If you are using a battery to feed them, what happens if you touch the battery positive to earth ground? what if you simply revert the polarity?

The greater the temperature in a filament the greater or lower is its resistance?
 
 

[Login to see usernames]

A capacitor and inductor do have the same reactances at resonance. think about it.

I have already removed that statement.   I misread.  My apologies.

TS
 


sorry i mistakenly edited your post while trying to post.

[Login to see usernames]

Is ok to run into confusion with so many terms.

I'm still curious about the light string stuff. it would be a serious flaw in ohms law. Even resistors won't have the same resistance. they have an acceptable range of precision. I think lamps are much worst precision in resistance.

Once i made a series cell with around 30 plates and connected the battery only to the end plates, the result was that only the end plates generated gas but i attributed this to the fact that they were all sitting in water and that probably the current preferred to leak thru the water than follow the plates route.