Understanding Amp Inhibit

Amplitude Attenuation (Voltage Boosting)

8XA VIC Chokes inhibit amps and raise voltage with bifilar winding and ferrite core.

Gated Pulse Frequency

Adjustable Duty Cycle Gated Pulse Frequency

One can use a 555 with two 1N4148 diodes to allow independent control of duty cycle ON/OFF times.

Each diode has a 100k 10-turn precision potentiometer placed in series to capacitor as shown below.Rotary switch for selection of different capacitor values can allow frequency range selectivity."RA" below can be a potentiometer to allow for frequency adjustment.

Photo from Electronic Tutorials: Electronic Tutorials (555)

In the build below, pin 3 of 555 was also output to CD4017 decade counter stage to produce a gate. This provided clock synchronization, and only allows 5 pulses per gate ON time.

Otherwise, any independent driver of CD4017 would produce clock drift and not allow a discrete number of pulse per gate ON time. Beauty of shift registers in 4017's is even though a 1mS ON time may be occurring, the whole period will be used to divide by 10.

Thus maintaining a 50% gated pulse time if desired. Both the adjusted pulse train from Pin #3 and output of CD4017 (Pin #12) is put into inputs (Pin #1 and Pin #2) of a 7408 AND logic gate chip. Pin #3 on 7408 is output, which is shown in yellow below on scope. Circuit driver side isolation may be achieved with H11D1 similar to the 9XA.

Gate can be adjusted by RA resistor to produce increase occurrences of pulse train

Pulse duty cycle ON time, down to lowest, measured at 1mS.

This method allows pulse duty cycle control, and synchronized gate to pulse train.

9XA Method

The 9XA was a circuit that Stan used to produce a gated pulse frequency via two H11D1 optocouplers. The optocouplers were driven by two independent stages of 555 timer clock frequency into 3 7490 decade counter ICs. The 7490s provided divisions of 555 frequency, but also produced 50% duty cycle pulses. Below, "A" is one 555/7490 stage and "B" is second 555/7490 stage. The two optocouplers produce an equivalent to AND logic gate.

Figure 1: 9XA schematic

Below is an 9xa scope shot, showing how two independent 9XB style frequency generator's outputs were used to trigger two H11D1 optocouplers to produce a gated pulse train as shown in schematic.

In this setup, I had 555's produce a 100khz output to 4 CD4017 dividers. This allowed a 10khz with 50/50 duty cycle to be achieved. LED is just for visual confirmation. If looking closely, you can see how the gating generator isn't synchronized with frequency generator.

This causes extra pulses to arise during gated ON times, also called "clock drift".

NOTE: CD4017s were used in place of 7490s, they accomplish the same task with less wiring required.

2nd setup had a modification where both signals from 555/CD4017 were fed into an 7408 AND logic gate. This produced the waveform seen below. In this instance, only 1 H11D1 optocoupler was required.

LED providing visual verification of pulse waveform.

9XA does provide a 50% duty cycle pulse frequency with a 50% duty cycle gate frequency. However, clock drifting is an issue if both waveform generators are used independently. If both decade counter stages are driven from same 555, a synchronized clock can be achieved. It is unclear if Stan synchronized with one 555.

Limitations of voltage amplitude for inhibiting electron leakage

Switching Latency

The adverse effects to pulse shape when inhibited by diodes and photo-diodes with nano and micro-second rise and fall times that exponentially induce latency per pulse.

H11D1 Opto-Coupler / Opto-Isolator

Hysteresis in magnetic cores

Magnetic Hysteresis

The lag or delay of a magnetic material known commonly as Magnetic Hysteresis, relates to the magnetisation properties of a material by which it firstly becomes magnetised and then de-magnetised.

We know that the magnetic flux generated by an electromagnetic coil is the amount of magnetic field or lines of force produced within a given area and that it is more commonly called “Flux Density”. Given the symbol B with the unit of flux density being the Tesla, T.

We also know from the previous tutorials that the magnetic strength of an electromagnet depends upon the number of turns of the coil, the current flowing through the coil or the type of core material being used, and if we increase either the current or the number of turns we can increase the magnetic field strength, symbol H.

Previously, the relative permeability, symbol μr was defined as the ratio of the absolute permeability μ and the permeability of free space μo (a vacuum) and this was given as a constant. However, the relationship between the flux density, B and the magnetic field strength, H can be defined by the fact that the relative permeability, μr is not a constant but a function of the magnetic field intensity thereby giving magnetic flux density as: B = μ H.

Then the magnetic flux density in the material will be increased by a larger factor as a result of its relative permeability for the material compared to the magnetic flux density in vacuum, μoH and for an air-cored coil this relationship is given as:

So for ferromagnetic materials the ratio of flux density to field strength ( B/H ) is not constant but varies with flux density. However, for air cored coils or any non-magnetic medium core such as woods or plastics, this ratio can be considered as a constant and this constant is known as μo, the permeability of free space, ( μo = 4.π.10-7 H/m ).

By plotting values of flux density, ( B ) against the field strength, ( H ) we can produce a set of curves called Magnetisation Curves, Magnetic Hysteresis Curves or more commonly B-H Curves for each type of core material used as shown below.

Magnetisation or B-H Curve

The set of magnetisation curves, M above represents an example of the relationship between B and H for soft-iron and steel cores but every type of core material will have its own set of magnetic hysteresis curves.

You may notice that the flux density increases in proportion to the field strength until it reaches a certain value were it can not increase any more becoming almost level and constant as the field strength continues to increase.

This is because there is a limit to the amount of flux density that can be generated by the core as all the domains in the iron are perfectly aligned. Any further increase will have no effect on the value of M, and the point on the graph where the flux density reaches its limit is called Magnetic Saturation also known as Saturation of the Core and in our simple example above the saturation point of the steel curve begins at about 3000 ampere-turns per metre.

Saturation occurs because as we remember from the previous Magnetism tutorial which included Weber’s theory, the random haphazard arrangement of the molecule structure within the core material changes as the tiny molecular magnets within the material become “lined-up”.

As the magnetic field strength, ( H ) increases these molecular magnets become more and more aligned until they reach perfect alignment producing maximum flux density and any increase in the magnetic field strength due to an increase in the electrical current flowing through the coil will have little or no effect.

Retentivity

Lets assume that we have an electromagnetic coil with a high field strength due to the current flowing through it, and that the ferromagnetic core material has reached its saturation point, maximum flux density. If we now open a switch and remove the magnetising current flowing through the coil we would expect the magnetic field around the coil to disappear as the magnetic flux reduced to zero.

However, the magnetic flux does not completely disappear as the electromagnetic core material still retains some of its magnetism even when the current has stopped flowing in the coil.

This ability for a coil to retain some of its magnetism within the core after the magnetisation process has stopped is called Retentivity or remanence, while the amount of flux density still remaining in the core is called Residual Magnetism, BR .

The reason for this that some of the tiny molecular magnets do not return to a completely random pattern and still point in the direction of the original magnetising field giving them a sort of “memory”. Some ferromagnetic materials have a high retentivity (magnetically hard) making them excellent for producing permanent magnets.

While other ferromagnetic materials have low retentivity (magnetically soft) making them ideal for use in electromagnets, solenoids or relays. One way to reduce this residual flux density to zero is by reversing the direction of the current flowing through the coil, thereby making the value of H, the magnetic field strength negative.

This effect is called a Coercive Force, HC .

If this reverse current is increased further the flux density will also increase in the reverse direction until the ferromagnetic core reaches saturation again but in the reverse direction from before. Reducing the magnetising current, i once again to zero will produce a similar amount of residual magnetism but in the reverse direction.

Then by constantly changing the direction of the magnetising current through the coil from a positive direction to a negative direction, as would be the case in an AC supply, a Magnetic Hysteresis loop of the ferromagnetic core can be produced.

Magnetic Hysteresis Loop

The Magnetic Hysteresis loop above, shows the behaviour of a ferromagnetic core graphically as the relationship between B and H is non-linear. Starting with an unmagnetised core both B and H will be at zero, point 0 on the magnetisation curve.

If the magnetisation current, i is increased in a positive direction to some value the magnetic field strength H increases linearly with i and the flux density B will also increase as shown by the curve from point 0 to point a as it heads towards saturation.

Now if the magnetising current in the coil is reduced to zero, the magnetic field circulating around the core also reduces to zero. However, the coils magnetic flux will not reach zero due to the residual magnetism present within the core and this is shown on the curve from point a to point b.

To reduce the flux density at point b to zero we need to reverse the current flowing through the coil. The magnetising force which must be applied to null the residual flux density is called a “Coercive Force”. This coercive force reverses the magnetic field re-arranging the molecular magnets until the core becomes unmagnetised at point c.

An increase in this reverse current causes the core to be magnetised in the opposite direction and increasing this magnetisation current further will cause the core to reach its saturation point but in the opposite direction, point d on the curve.

This point is symmetrical to point b. If the magnetising current is reduced again to zero the residual magnetism present in the core will be equal to the previous value but in reverse at point e.

Again reversing the magnetising current flowing through the coil this time into a positive direction will cause the magnetic flux to reach zero, point f on the curve and as before increasing the magnetisation current further in a positive direction will cause the core to reach saturation at point a.

Then the B-H curve follows the path of a-b-c-d-e-f-a as the magnetising current flowing through the coil alternates between a positive and negative value such as the cycle of an AC voltage. This path is called a Magnetic Hysteresis Loop.

The effect of magnetic hysteresis shows that the magnetisation process of a ferromagnetic core and therefore the flux density depends on which part of the curve the ferromagnetic core is magnetised on as this depends upon the circuits past history giving the core a form of “memory”. Then ferromagnetic materials have memory because they remain magnetised after the external magnetic field has been removed.

However, soft ferromagnetic materials such as iron or silicon steel have very narrow magnetic hysteresis loops resulting in very small amounts of residual magnetism making them ideal for use in relays, solenoids and transformers as they can be easily magnetised and demagnetised.

Since a coercive force must be applied to overcome this residual magnetism, work must be done in closing the hysteresis loop with the energy being used being dissipated as heat in the magnetic material.

This heat is known as hysteresis loss, the amount of loss depends on the material’s value of coercive force.

By adding additive’s to the iron metal such as silicon, materials with a very small coercive force can be made that have a very narrow hysteresis loop. Materials with narrow hysteresis loops are easily magnetised and demagnetised and known as soft magnetic materials.

Magnetic Hysteresis Loops for Soft and Hard Materials

Magnetic Hysteresis results in the dissipation of wasted energy in the form of heat with the energy wasted being in proportion to the area of the magnetic hysteresis loop.

Hysteresis losses will always be a problem in AC transformers where the current is constantly changing direction and thus the magnetic poles in the core will cause losses because they constantly reverse direction.

Rotating coils in DC machines will also incur hysteresis losses as they are alternately passing north the south magnetic poles.

As said previously, the shape of the hysteresis loop depends upon the nature of the iron or steel used and in the case of iron which is subjected to massive reversals of magnetism, for example transformer cores, it is important that the B-H hysteresis loop is as small as possible.

In the next tutorial about Electromagnetism, we will look at Faraday’s Law of Electromagnetic Induction and see that by moving a wire conductor within a stationary magnetic field it is possible to induce an electric current in the conductor producing a simple generator.

Amp Restriction

10 Stages To Amp Restriction in the VIC

Voltage intensifier Circuits

Variable Pulse Voltage Frequency adjusted to keep amp flow to a minimum
Variable Gated Pulse is adjusted to reduce amp flow still further, while allowing voltage amplitude and pulse frequency to be adjusted to tune into higher gas yields
Resistive Wire 430/FR on Secondary Coil ( used in latter versions 9 to 11)
Weak Air Space between Primary/Secondary coupling is a stop gap method of restricting amps since no electrical connection exists inside said air-gap
Amp restricting functions prior to Transformer Action prevent "Power Drop" during pulsing operations under load
Resistive Wire 430/FR in Resonant Charging Chokes ( used in latter versions 9 to 11)
Natural Water having 20ppm / Chemical Interaction held to a minimum since amps are restricted
Cavity Insulation - Prevent Electrical Leakage and said applied voltage pulses retain much higher voltage potential during gas production. Seals off said voltage gap by preventing electrical leakage to said water supply. Voltage concentration is now accomplished during gas production.
Pulsing Circuit remains the same with more excitor pairs added. Power loss is held to a minimum
Primary / Secondary Weak Coupling