Rosemary Ainslie circuit demonstration on Saturday March 12th 2011

[TheCell]

IMO when a negative voltage is measured across the shunt (as a mean average), which clearly indicates that power is transfered to the batteries and heat is dissipated from the load , that would be enough proof for that this is a heater in self run mode.

@p99 : If the mosfets are not in parallel ; I don't see a circuit providing them with a individual gate voltages.

@RA : Are still mosfets with the flyback zehner diode in use, or without.
I think that the form of the signal supplied to the gate , its offset ect. are crucial for getting this ringing mode .Is there a adjustment procedure that must be carried out ? Thank you.

[Rosemary Ainslie]

IMO when a negative voltage is measured across the shunt (as a mean average), which clearly indicates that power is transfered to the batteries and heat is dissipated from the load , that would be enough proof for that this is a heater in self run mode.

@p99 : If the mosfets are not in parallel ; I don't see a circuit providing them with a individual gate voltages.

@RA : Are still mosfets with the flyback zehner diode in use, or without.
I think that the form of the signal supplied to the gate , its offset ect. are crucial for getting this ringing mode .Is there a adjustment procedure that must be carried out ? Thank you.

I am not sure of your question.  Yes we're using IRFPG50's and yes, they've got that zener body diode.  The adjustments are only applied as required.  It depends on the 'output' you're looking to.  Then we adjust the 'off set' and the duty cycle.  Beyond a certain level it exceeds the resistance at the gate of the first MOSFET.  Then it's difficult to hold back that energy.  But the point is this.  The oscillation persists.  There is no resulting 'equilisation' (if that's the word) of that energy.  If you disconnect the batteries then the temperature across the load falls dramatically and quickly.  But that oscillation 'retains' that temperature.  It's still 'working' in the sense that you all think of the word.  It's just that the temperature - that heat dissipation - has NOTHING to do with a loss of charge.  Sorry.  I should have said potential difference.

What we've got on this circuit that is entirely unusual and eccentric is an AMPLE path for the forward and reverse current flow.  There are NO restrictions.  And it appears - that under these cicumstances current just keeps moving.  That should not - in terms of classical requirements - ever occur.  The battery voltage climbs or falls.  The circuit voltages climb or fall.  They NEVER resolve themselves into that 'required' balance. 

I hope that's clearer and I hope more of you readers are looking at the actual question here.  And thanks TC for the question.

Kindest regards,
Rosemary

edited

[neptune]

Hi Rosemary on this beautiful spring day in the UK .I am a little bit confused here due to info overload .
1 . In the photo you show of the custom made element that fits in the canister , there appears to be only one Mosfet .Is this correct and does the circuit show overunity with only one mosfet?
2 Are you saying that the circuit works best with 5 Mosfets in parallel , 4 of which have their source and drain connections reversed , or all 5 have these connections reversed .
       Perhaps when you have time , you could show a revised diagram showing the optimum arrangement .Continue to fight the good fight .All the best Neptune .

[Sprocket]

Rosemary, I'm following along quietly, have some stuff ordered but my main 'must-have' is still a decent function generator.  I really envy those guys States-side as there is tons of kit available on eBay with dirt-cheap shipping.  But it looks like I'm going to have to order one from China, but with a few 100 $ of stuff already in transit from there, I'm waiting to see if Customs here will be out to screw me financially.

Anyway, main purpose of post, a few questions that I am confused over.

1:  If as now seems to be the case the mosfets are not in parallel, how exactly are they configured?  This is kinda important!
2:  When you blew the 2 mosfets, you admitted that you had a problem reproducing the 'effect'.  With some effort you got it going but didn't explain what the difficulty was.  If you have problems getting it to operate, what about the rest of us!
3:  How much heat is generated by the mosfets?  Those are pretty hefty heat-sinks you are using, if you don't have an accurate way of measuring the temperature, could you at least estimate their running-temperature.
4:  Have you since tried adding additional external shunt-diodes to protect the mosfets - presuming it was over-voltage that took out your 2 mosfets?

Thanks.

[poynt99]

For those that are having trouble visualizing the non-parallel mosfets 2-5, here is an edited version of their diagram. It is the Gate and Source that are swapped, not the Drain and Source btw.

.99