Kapanadze Cousin - DALLY FREE ENERGY

[itsu]

@Itsu

With that horizontal scope resolution you are blind to the influence of MOSFET's gate capacitance on the rise time and fall times of the TL494 outputs.

Thanks for the info verpies.

i will start building a toroid using 7 prim. turns each first (easier to remove turns then to add) and do some testing.
Then decide to use drivers (max4420) or not.


I also received my LT1073's and mur diodes, so can start building your nanopulser.

Regards Itsu

[verpies]

I will start building a toroid using 7 prim. turns each first (easier to remove turns then to add) and do some testing.
Then decide to use drivers (max4420) or not.

Yes. I usually wind one full layer of turns, because you can always unwind them later and excessive turns do not affect the current rise-time measurements negatively and the increased inductance always offers more protection to the driving transistors.

[Pinoy_Tech]

 Sir Itsu, I think you have all info’s to build your toroid trafo but to answer & give you also few details on my pre-tested toroid, I just picked it from my old smps (on pfc circuit) with a dimension of about 5 x 3cm od. I just added a few turns to stand as a primary windings with NP of just 4T while I kept the original windings to stand for my secondary having a number of turns of about 43T x 2 @ approx 1mm dia each.  The primary wire is just an ordinary stranded wire taken from the output of an old pc smps. I cut 2 of them and twisted both ends then that end is used as my center tap. The direction is maybe a bit confusing to many diyer’s if we will not mention the right reference. If we will start from center tap, then one side will be CW while the other side will be CCW, but if we will just start from one end towards center tap ‘till another end, then all windings will be in one direction only.  Secondary is either CW or CCW is not a problem because we are dealing with push-pull topology except if we will sync the starting pulse to another circuit... My output reading with 127V/60W lamp load is around 200VAC in my analog meter but of course this is still considered false AC reading for a high frequency like this.     

You plan to remove few parts before the gate. As I know they are not drivers but a clamp circuit to improve the waveform going to the gate. I observed during my waveform measurements, it helps to chop those unwanted impulse that interfering the proper operation of the driven mosfets. So, I kept the circuit as it is and it is the same idea as Mr Dally’s recommended schematic.
Best regards,
576Pinoy_tech   

[itsu]

Pinoy_tech,

Sir Itsu, I think you have all info’s to build your toroid trafo......

Thanks for this data, and good to know this:

As I know they are not drivers but a clamp circuit to improve the waveform going to the gate.

I will find out during my tests.          Regards Itsu 

[verpies]

This is a little bit off-topic but it might help some experimenters who are pulsing inductors.

When a rectangular pulse transitioning abruptly from 0 to some voltage V is applied to an inductor (e.g. coil) and a resistor in series, the following sequence of events happens:
1) At the beginning (point A) no energy and no current is flowing.
2) Shortly after the rising edge of the stimulating pulse, the current increases linearly
3) Some of the energy of the pulse is converted into the magnetic field in the inductor and some energy is dissipated in the resistance as heat. At this point the energy flows into the inductor faster than it is dissipated by the resistor.
4) After the time equal to 0.69 Tau (point B) the energy flow (a.k.a. power) into the inductor reaches its peak and start decreasing afterwards, eventually reaching zero power and magnetic energy equal to 0.5*L*((V/R)^2) at Tau >> 5
5) However the current through the resistor keeps increasing non-linearly but monotonically and asymptotically up to the V/R limit and the energy flow (a.k.a power), dissipated as heat in the resistor, increases similarly up to the (V^2)/R limit.
6) After time equal to 1.15 Tau (point C), the magnetic energy accumulated in the inductor reaches the break even point with the total energy dissipated as heat in the resistor up to that point in time. Continuing beyond point C guarantees that more energy is dissipated as heat in the resistor than stored as the magnetic field of the inductor.
7) After a very long time the current reaches the V/R limit and the magnetic energy stored in the inductor reaches 0.5*L*((V/R)^2) limit but the energy dissipated in the resistor increases ad infinitum at the rate (a.k.a. power) equal to (V^2)/R.

Tau = R/L (a time constant)
V = The high level voltage of the stimulating rectangular pulse.
E_TOT = Total energy delivered by the supply to the series RL circuit.
E_L = Energy stored in the inductor as magnetic field
E_R = Energy dissipated in the resistance as heat
P_L = Instantaneous Power (energy flow) flowing into the inductor
P_R = Instantaneous Power (energy flow) dissipation in the resistance
i_L = The current flowing through the inductor (and resistor)

For transformers, putting a load on the secondary winding (e.g. shorting it) has the same effect as decreasing the inductance of the primary winding (L). As a result of this, the Tau decreases and the current in the primary rises faster with time.