Richard VIALLE's new theory about negative mass and overunity

[verpies]

- I've tried adding small amounts of inductance & or capacitance in series or parallel with the bulb, and have only seen the bulb dim.

That's to be expected.  Inductance in series decreases the average current through the bulb at high frequencies.  That's why I asked you to measure the inductance of the bulb (note that I did not ask you to add inductance to the bulb).  For a bulb to be a good indicator of output power at high frequency it has to have a straight filament (or low pitch helix filament) so its inductance is at the minimum.

- I've tried connecting the GND to one or other of the bars - and that gives a small increase in brightness - when connected to either bar.

That's hard to explain.  For sure such connection shorts out the stray capacitance formed between the device and the ground.

There are 2 reasons why it looks like the effect is due to capacitive coupling:
1) The addition of the ferrite cores makes no difference
2) Placing my hand on the coil makes the bulb go out. If it was magnetic - I don't see how this could happen.

That's logical reasoning.

Relative Power Usage
- The test bulb with 12v DC uses 0.4a, and makes about 40,000 Lux (as tested with a luxmeter at zero distance)
- If powered by the circuit - the bulb needs about 45v and 0.3a to reach the same brightness. (Ignoring the gate driver)

That's a good test of the output power if the luxmeter does not get saturated and the inductive reactance of the bulb is low.  Putting the bulb and the sensor in a dark box would be prudent (see Grumage's Wattbox).
However the bulb is not a good indicator of the input power at all, because a bulb in series with the input measures current, not power and the MPTT rears its ugly head.

- If it is capacitive coupling, I don't understand why it has particular resonance points. I suppose caps do have their own resonances...

Capacitances form frequency-selective LC tanks with delibrate and stray inductances.

Also, don't forget about the formation of standing waves, which are easily disturbed by the change in length of the reflecting medium, speed of propagation (affected by capacitances and inductances) and position of reflection points and impedance mismatches at reflection points (also affected by capacitances and inductances and resistances there).

- I want to try running the coil with the ZVS driver - it's likely much more efficient.

A Mazzilli circuit?
If so, it might be more efficient but also less controlable.  You will not be able to tune its frequency precisely.

[tim123]

That's to be expected.  Inductance in series decreases the average current through the bulb at high frequencies.  That's why I asked you to measure the inductance of the bulb (note that I did not ask you to add inductance to the bulb).

Hi Verpies,
  I did try to measure the inductance using a meter, but it couldn't get a reading - it came up with a negative value.

However the bulb is not a good indicator of the input power at all, because a bulb in series with the input measures current, not power and the MPTT rears its ugly head.

I don't really get that TBH - surely the bulb is showing real power - as it needs both volts & amps in phase etc...?

I do get how there's an 'optimum' load - i.e. resistance - that is apparent in the circuit. It 'feels' like the small bulb isn't too far off ideal. The 60w bulb is terrible - i.e. far too high resistance - virtually no power transfer. The LEDs are good.

If the bulb's resistance was the same as the supply - would it then show real power accurately?

Capacitances form frequency-selective LC tanks with delibrate and stray inductances.
Also, don't forget about the formation of standing waves...

It is interesting that all versions of the Vialle gen. have similar resonant frequencies. I wonder if the U-shaped bar also has a higher resonance at around 7.2 MHz like my small one does...

It's odd that mine works at 3.7MHz - despite only being 1/3 the length of the normal version. I currently have no hypothesis to account for that.

A Mazzilli circuit? If so, it might be more efficient but also less controlable.  You will not be able to tune its frequency precisely.

Yes. Agreed about the frequency being difficult to predict / set - I do have some variable caps though. To get it working at 4 MHz would need a coil with very low inductance and low self-capacitance too. Which might be difficult to acheive.

Unfortunately I have replaced the mosfets, but the driver's still not working... It'll take another leap of understanding for me to fix it.

[verpies]

I don't really get that TBH - surely the bulb is showing real power - as it needs both volts & amps in phase etc...?

Actually the brightness of the bulb depends only on current in any direction ( P=I²R ).

For a bulb measuring the output power, the current depends only on output voltage and bulb's resistance (I=V/R_BULB)
For a bulb measuring the input power, the current depends on power supply's voltage and bulb's resistance and DUT's resistance* ( I=V/(R_BULB + R_DUT)) ).

* actually complex impedance = reactance + resistance. (X+R)

If the bulb's resistance was the same as the supply - would it then show real power accurately?

Only if it was the sole receiver of that power.  If there is another element in series with that bulb (e.g. DUT), then it will not be a good indicator, since the resistance of that additional element will disturb the 50% power sharing ratio between the PS & bulb.

That's why you can trust non-inductive bulbs to accurately indicate output power (because in that case the bulb is the indicator and load in one and the MPTT can be applied only to 2 devices: PS and the bulb).

However, you cannot trust non-inductive bulbs to accurately indicate input power (because in that case the bulb is not the indicator and load in one - it is merely an intermediary between the power supply and a 3rd element in that circuit (e.g. DUT).  Thus the MPTT must be applied to 3 elements: PS, bulb and the DUT.

[Khwartz]

Hi Folks,
  It's all working ok, and I have some results...

1) I'm able to light a small incandescent bulb from the 2 copper tubes in the coil. Picture attached of the setup.
- The resonant frequency for my 2 6" copper tubes is around 3.7MHz.
- It is a sharp resonance being much dimmer at 3.6 or 3.8MHz, an the lamp doesn't light at all past about 3.5/3.9Mhz...

2) Power into the transistor is about 60v, and 0.37a (about 22w)

3) The gate-driver setup has a sweet spot at about 5.7v.
- It keeps the current through the gate & the mosfet reasonably low, but there's a peak of lamp brightness there too.
- Above 5.7v the load current reduces, and the lamp dims, up to about 7v where it reaches it's former brightness again.

4) The scope shot shows:
- Yellow - the Gate voltage
- Blue - the Drain voltage

5) I think my gate driver needs power resistors - the 1/4w ones can't take the current with the full 15v available. They get very hot at 9v.
They're currently at 10 Ohms, I'm tempted to try 5 Ohms to see if I can improve the gate signal.
The UCC211 can handle 0.3a continuous at 18v according to the specs - so a pair of 5 watt resistors maybe?
Maybe I'll just put a load of 1/4w ones together so I don't have to worry about them burning out...

6) In order to measure the input & output HF power, I'd like to build something like Verpies HF wattmeter...
I suppose an off-the-shelf SWR meter would be good enough to make relative measurements though...


Tim

Hi tim.

Nice to see you are in progress

For reducing load for power consumption protection, I understand what you mean, but remember that more the output is (short-circuit and light bulb are powerful), more the negative power has changes to take place at the input. 

For SWR meter, do you mean like a mini NVA or a HF FWard BWard power meter & SWR Meter? If last one, Blue has registered funny behaviours in his last vid.

Cheers
K.

[Khwartz]

I've combined 2 lots of 5, 47 Ohm, 1/4w resistors, to make 9.5 Ohms, 1.25w resistors - for the gate driver. I feel much happier now - though they do still get hot at higher volts.

And some more results:
- I've found a new resonance at 7.3MHz - which lights the bulb more brightly, for less power...
- and a few others too - here's a list:
(apologies for the subjective bulb-brightness-units )

  Frequency         Bulb Brightness            Power Supply
-----------------  ---------------------------  -----------------------
- 1.5 MHz          Weak
- 1.8 MHz          Less Weak
- 2.45 MHz        Strong                           0.61a at 46v
- 3.7 MHz          Stronger                        0.49a at 46v
- 7.3 MHz          Strongest                      0.42a at 46v

Another note:
- The ferrite rod-cores make no difference at all to the operation of the device...!
- I've tried them in and out at the resonance points, and the performance is the same, and the tuning is the same too.


Tim

Nice results and Very Well presented!  Imho