Rosemary Ainslie circuit demonstration on Saturday March 12th 2011

[Sprocket]

Indeed.  They were donated Sprocket.  We were very glad of the donation.  But they are huge.  Surprisingly there's no wattage rating detailed.  Rather remiss.  We've still have to get that established.

Rosemary

It would have been nice to see the same charging-effect with much smaller batteries.  I had a stab at this when you were posting on EF but couldn't find anything out of the ordinary.  I managed to blow a few mosfets but still have a few unused ones still, might have another go.  I also have loads of Nokia 3.6v NiMH cell-phone batteries, 20-30 of these in series would match your setup, volts-wise anyway.  The 5-in-parallel thing is interesting - does this enhance the effect a lot, 5-fold perhaps?

[Rosemary Ainslie]

It would have been nice to see the same charging-effect with much smaller batteries.  I had a stab at this when you were posting on EF but couldn't find anything out of the ordinary.  I managed to blow a few mosfets but still have a few unused ones still, might have another go.  I also have loads of Nokia 3.6v NiMH cell-phone batteries, 20-30 of these in series would match your setup, volts-wise anyway.  The 5-in-parallel thing is interesting - does this enhance the effect a lot, 5-fold perhaps?

Hi again Sprocket.  It would be good to see your results here.  Everyone's interested in exploring which batteries and what exactly they contribute.  The difference with this and previous tests is only in that negative triggered oscillation.  That's the parasitic oscillation that's normally thrown away.  What we see is that this allows for a hefty current flow and my own take is that - in parallel - they can manage the current potential that one MOSFET by itself - just doesn't.  But there are other things that are strange.  I'll try and get around to this later on tonight. 

Not sure why your previous didn't work.  That early test is actually very easily replicated.  But it probably needs the help of a high level scope - just to tease out the right tuning.  Not the easiest.  And one needs to know what to look for.  Again.  For me this side of the exercise is relatively easy.  I have never been hampered by conventional expectations.  LOL.  I think there may be some advantages to not having a classical training.  Perhaps.  Anyway.  Good luck with your efforts.  I'm sure we'd all like to hear what happens - good or bad.  It's all likely to add to the general pool of knowledge.  Never a bad thing.

Kindest regards,
Rosemary   

[neptune]

I found this video to be clear and informative . Vital info is here for the taking .As I long suspected , the input signal on the mosfet gate toggles between about 5 volts positive and 4 volts negative . This is not a wave form you are going to get with the published 555 timer circuit as it stands . There are people reading here who could overcome this problem of voltage offset . Of course on the video it is overcome using a function generator to do the job . Rosemary , a sudden thought . If it is the Zener diodes that form the path for oscillation , why not just add additional zeners across the drain and source terminals of the fets , in parallel with the internal diodes , and see if the effect is enhanced ? Choose the diodes to have a breakdown voltage just higher than the highest battery voltage .

[Rosemary Ainslie]

I found this video to be clear and informative . Vital info is here for the taking .As I long suspected , the input signal on the mosfet gate toggles between about 5 volts positive and 4 volts negative . This is not a wave form you are going to get with the published 555 timer circuit as it stands . There are people reading here who could overcome this problem of voltage offset . Of course on the video it is overcome using a function generator to do the job . Rosemary , a sudden thought . If it is the Zener diodes that form the path for oscillation , why not just add additional zeners across the drain and source terminals of the fets , in parallel with the internal diodes , and see if the effect is enhanced ? Choose the diodes to have a breakdown voltage just higher than the highest battery voltage .

Hello Neptune.  We've used diodes across the switch - often.  It works.  But I've never seen anything work like this does.  If we need more current drawn then it's possibly for that 'booster' mode.  Then - I'm quite simply more anxious to hold back the potential than otherwise.  It's already spiking at values that are almost too big for our DSO's. 

Kindest regards
Rosemary

[neptune]

Hi Rosemary . Could you please clarify two points from the video . Is the heating element in the canister immersed in water , or just air . Also , the 5 mosfets are mounted on separate heatsinks . Are these heatsinks electrically isolated /insulated from each other? From the experimenters point of view , does the higher efficiency of the present element justify its additional complexity and expense when compared to a simple wire wound element on a ceramic core?