Claimed OU circuit of Rosemary Ainslie

[0c]

GAHH!!!
It never stops with this madwoman.
...

I guess there's those who "can't handle the truth"!

And then there's some of us who want "The truth, the whole truth, and nothing but the truth". I currently have 3 suggested original projects here, and one on another forum discovered by someone else, that have not managed to come to a final conclusion. I would sure like to see some final resolution on at least one of them.

0c

[qiman]

Anyone that wants the modified Quantum article that gives the exact ranges needed, use this:

[MileHigh]

Aaron:

For you latest video you indicate that the probe is connected across the gate input, which is the same as the 555 timer output.  The 555 output is 27.6% duty cycle and the frequency is 1.347 KHz.

Then you connect the main battery to power the setup and you say, "now you can see the oscillation."  This is most likely wrong.

I can envision two scenarios:

1.  For whatever reason, when you connected the battery the scope lost trigger.  So what you are describing as "oscillation" is just the 555 timer signal running at the same 27.6% duty cycle at 1.347 KHz but without a locked trigger.  When you saw that happen the first thing that should have run through your mind is that you lost trigger.  If the MOSFET itself was in oscillation, there is no logical reason for it to affect the 555 output signal being read at the MOSFET gate input.

2.  The 555 output really does "go crazy" when you connect up the main battery to the circuit.  That would imply that you have a 555 circuit that is loosing stability and extra sensitive to the external environment.  This should not be happening, the 555 circuit should be very robust and extremely immune to outside influences.  I mentioned another time for one of your 555 circuits that the resistor values may have been too high and your capacitor values may have been too low, which would make the circuit less robust and possibly sensitive to outside influences.  I noticed that one of the caps that you are using is 0.001 uF, or 1000 pico-Farads (thank you Joit).  I am not sure if this particular cap is one of the main timing caps for the "off" or the "on" time constant, but if it is, I would be concerned.  It is a microscopic capacitor value.

Then at 0:59 in your clip you can see that the frequency is 65 KHz.  So the question is, how did you go from 1.347 KHz to 65 KHz?  Also and very importantly, you can see that the duty cycle looks like it is now 98% "on".  It looks like scenario #2 above provides a partial answer.  The 555 output does not "go crazy" because you can see it is very stable at 65 KHz.

So that leads into the next question, how can you explain going from a stable 1.347 KHz 555 output at a 27.6% duty cycle, to what appears to be a stable 65 KHz 555 output with a 98% duty cycle???  I know that the first thing you want to say is "CONFIRMATION OF OSCILLLATION!!!!!" but NO, you have to check if the 555 output itself is running at a stable 65 KHz and check the duty cycle.  If that is the case, then the circuit is not oscillating, it's just running at the higher unexplained 555 clock frequency.

You claim that the shunt waveform never goes to zero, but that is impossible if we are assuming that the MOSFET is switching off.  You can pretty much see the shunt voltage going to zero at 1:15 in your clip.

Then you switch over to looking at the load resistor.  You can see the big negative spikes that are smacking into the switched-off MOSFET.

Now you appear to have a new fixation, "It does NOT settle at zero volts.  This is what you want."   Dare I ask Aaron, can you explain WHY this is what is wanted?  At the same time, can you explain WHY "resonance" or "oscillation" will give you better results?

At a fairly high frequency of 65 KHz and with a 98% "on" duty cycle it is normal and expected that the scope will show you that the voltage across the coil-resistor, a.k.a.; the load resistor, will stay above ground.  The MOSFET is only switching off for a very short time, so the coil may not get to completely discharge and some DC current is running through it all the time.  This fact plus the fact that there  is stray capacitance will give you the waveform you see:  a DC offset voltage with a train of regular negative DC spikes corresponding to the coil partial discharge.  All of these effects do NOT add up to "oscillation."

This is another video of the full blown "parasitic hartley effect".

No it is not, there is no confirmed evidence of any "oscillation" or "resonance" in your clip.  I suggest that you investigate the unexplained frequency and duty cycle change that appears to be happening to the 555 circuit and fix that problem before you do any more testing.

MileHigh

[MileHigh]

News from the "other side of the tin can and waxed string":

About the Michael John Nunnerley TRIAC-based water heater project:

The first thing I think is that the bemf is totally free.

Reduction in power consumption over base line of direct power to inductive element only= 39% over same time period and temp: differencial

Any thoughts anyone?

You may not have caught it, I already mentioned that it appears that you can make your heating element act as a mostly inductive load if you chop off the power early in the cycle with your TRIAC controller.  Did you hack into a TRIAC-based light dimmer?  Then the coil discharges into your secondary heating element and heats the water.  This energy is not "free", it came from your AC mains supply.  The "free" part is that your electrical meter most likely cannot measure any reactive power and your setup basically converts the load as seen by the power company from a normal load into a reactive load.

If you try to develop this as a real product and put it on the market you will be shut down by the EU regulatory agencies in your country.  If you imagine that you did get approval, then the power companies would go after you and take you to court.

And no Aaron, you speculated about some "magic" power savings for your water heater in your home by adding a capacitor in the mix.  Ain't gunna happen.

MileHigh

P.S.:  No disruptions from you Aaron.

[Hoppy]

I've built and run Aaron's latest circuit mod and I have managed to send my mosfet into the 'oscillation' I think Aaron is referring too. I had a glimpse of the spikes on the scope for a short while before the mosfet failed due to a short circuit after overheating! It appears to be a fairly critical adjustment which I was unable to repeat. The mosfet appears to be running into some kind of thermal runaway in this condition. Aaron is probably able to control the onset of this by very careful tuning at around the point it occurs. There is a distinctive change of tone as he has reported. 

The important thing is that Aaron appears not to be monitoring his supply current whilst tuning his circuit, because if he was, he would clearly see that the supply current suddenly increases dramatically in this 'oscillatory' condition. This is probably being masked by high capacity of his battery. I suggest he places a 10Amp analogue ammeter in series with his battery and take note of the current draw as he tunes his circuit to he 'optimum' point.

I'm running on a 24V supply made up of 2 x 12, 2.8A/hr SLA batteries and the drop in terminal voltage in this oscillatory state was considerable. My inductive resistor was 8.9uH for this test run.

I can now see some variation in the spikes when the gate resistor is adjusted but in all cases with my tuning, inreased spikes results in a higher current draw.

I will post some scope shots of the stable waveforms I am getting from this Ainslie circuit mod in the morning.   

Harvey's proposed Ainslie circuit mod just would not work for me.

Now to bed!

Hoppy