Claimed OU circuit of Rosemary Ainslie

[fuzzytomcat]

Glen.

May I ask where your scope probe that's monitoring the battery voltage is located exactly?

i.e. is the scope probe clipped on to the resistor or is it clipped on to the battery + terminal?

Where are the probe grounds connected?

.99

Hi .99,

Here is a photo for you showing the Tektronix TDS 3054C probe locations .... the 24 Volt battery bank probe (blue band) is 6" from the "red" connector, the red and white AWG 14 wire go directly to the battery's.

Fuzzy   

[Rosemary Ainslie]

.99:

I am going to briefly try to finish off the ringdown if you and others will indulge me.

Referencing the third graph in the original post:
http://www.energeticforum.com/69850-post2875.html

And the first graph in this post:
http://www.energeticforum.com/70025-post2893.html

Whatever is going on, it looks like once the MOSFET switched off completely there is already high potential associated with the LCR circuit ready to push current in a counterclockwise direction and it is directly proportional to the potential of the drain node.  If I put an imaginary "phantom (freewheeling?) diode" across the coil, then indeed there is a parallel path for the capacitance to start pumping current in a counterclockwise direction.

MileHiigh

Hello MileHigh.  This is the only part of the anlaysis that I like.  BUT WHAT FUN.  Have just woken up and am still hopelessly up there.  In fact I think I see you at eye level.  Quite rare for me especially this early into the day.

EDIT.  Sorry.  This was another 'barometer'.  I promise.  Never again - if I can help it.

[Hoppy]

.99:

I am going to briefly try to finish off the ringdown if you and others will indulge me.

Referencing the third graph in the original post:
http://www.energeticforum.com/69850-post2875.html

And the first graph in this post:
http://www.energeticforum.com/70025-post2893.html

Do you notice how the big drain spike actually has two parts?   The first part being a sinusoidal stray capacitance charging phase, and then a regular RC exponential decay curve through the 10-ohm resistor and the body diode for the second phase.

There is a glitch during the discharge and I assume that is the body diode shutting off then the inductor spikes some current through it again.

I am not sure what you guys/gals mean by a "freewheeling diode?"  I am trying to pin down the mechanism for initiating the reverse current flow.  Certainly you can see that when the current is at zero, the fight with the switching off MOSFET has already pumped the potential to 100 volts.

It looks to me that at that point in time, you have a cap charged to 100 volts that is capable of discharging through the coil + 10-ohm resistor + battery + shunt resistor + body diode.  At the same time the coil has another 100 nanoseconds worth of discharge power charging the capacitance.  The coil has current going through it in two different directions for a certain net current.  Or am I missing something about the "freewheeling diode?"

Whatever is going on, it looks like once the MOSFET switched off completely there is already high potential associated with the LCR circuit ready to push current in a counterclockwise direction and it is directly proportional to the potential of the drain node.  If I put an imaginary "phantom (freewheeling?) diode" across the coil, then indeed there is a parallel path for the capacitance to start pumping current in a counterclockwise direction.

MileHiigh

MH

The condition needed to invoke a reverse discharge current flow through the battery and mosfet body diode is the lack of a diode ('freewheel diode'). across the inductor. If the 555 were to powered from the same supply, then this would clearly present a nice path for the discharging current, very likely resulting in a smoked 555 at some point if the inductance / spike amplitude was high enough, or at least erratic operation as we observe. The higher the coil inductance is, the more likely the 555 will be 'spiked', or at least display erratic operation. The inductor will discharge its stored energy in any which way it can, when its source of power is abruptly disconnected.

The folly of powering the 555 switch from the same supply, or even a seperate supply with a common earth (star earth) is that it makes analysis of the resulting complex waveforms very difficult. It makes much more sense to me if the switching is opto isolated, so that the discharge can be studied without the added complication of the effects that the 555 common power connection present.

Hoppy

[Hoppy]

I see that OU is now being claimed on EF for the Ainslie circuit on the strength of Fuzzy's new data. I'm surprised to see absolutely no mention of energy consumption in his results - Energy= Power (Watts) * Time (seconds). A serious OU claim cannot be made without energy levels being computated.

Hoppy

[poynt99]

I see that OU is now being claimed on EF for the Ainslie circuit on the strength of Fuzzy's new data. I'm surprised to see absolutely no mention of energy consumption in his results - Energy= Power (Watts) * Time (seconds). A serious OU claim cannot be made without energy levels being computated.

Hoppy

I agree and have mentioned it to Rose. Apparently they have done some number crunching, but I have not seen it.

.99