Claimed OU circuit of Rosemary Ainslie

[Harvey]

Well I don't visit this side that often - I punched in here on page 142, saw Mile Highs post regarding the 555 back there, (Sorry MH, your wrong about the 555 supply voltage messing with the timing), skimmed a couple of posts and realized I should just skip to the end.

Evidently we do need a current limiter on these timers during this type of testing. I blew out my trusty 30 year old NE555 from 1980 tonight when the circuit went into aperiodic oscillation. The timer section was still clocking, but the output was hosed. It seemed to be tracking the discharge pin, no flipity floppity. This confirms my suspicions that resonant pulses are punching through the drain-gate capacitance at specific frequencies and routing through the output sink of the 555 and also making its way back to the reset transistor internally.

Also, MH - if you read the specs on the 555 you will find that the timing cap energy runs through the discharge pin which is only limited by case dissipation, nothing we are doing is pegging that.

I isolated the 555 from the HEXFET with a 40106BCN and found that the charge requirements are almost starving even with all six gates being used to pump it. There was no self oscillation and no retriggering with that circuit. That's when I pulled my 1.6ohm protection resistor from the gate and smoked the 555.

I am seeing way too many variables associated with this circuit and wonder at this point if anyone will be able to accurately produce with today's parts, the effects Rosemary once experienced 10 years ago. I will continue to try, but so far I am not getting the heating I expected.

Well, didn't mean to blog here - just stopped in briefly -

Cheers,

[Hoppy]

Well I don't visit this side that often - I punched in here on page 142, saw Mile Highs post regarding the 555 back there, (Sorry MH, your wrong about the 555 supply voltage messing with the timing), skimmed a couple of posts and realized I should just skip to the end.

Evidently we do need a current limiter on these timers during this type of testing. I blew out my trusty 30 year old NE555 from 1980 tonight when the circuit went into aperiodic oscillation. The timer section was still clocking, but the output was hosed. It seemed to be tracking the discharge pin, no flipity floppity. This confirms my suspicions that resonant pulses are punching through the drain-gate capacitance at specific frequencies and routing through the output sink of the 555 and also making its way back to the reset transistor internally.

Also, MH - if you read the specs on the 555 you will find that the timing cap energy runs through the discharge pin which is only limited by case dissipation, nothing we are doing is pegging that.

I isolated the 555 from the HEXFET with a 40106BCN and found that the charge requirements are almost starving even with all six gates being used to pump it. There was no self oscillation and no retriggering with that circuit. That's when I pulled my 1.6ohm protection resistor from the gate and smoked the 555.

I am seeing way too many variables associated with this circuit and wonder at this point if anyone will be able to accurately produce with today's parts, the effects Rosemary once experienced 10 years ago. I will continue to try, but so far I am not getting the heating I expected.

Well, didn't mean to blog here - just stopped in briefly -

Cheers,

Hi Harvey,

Great video. We have four pots to play with, so yes lots of variables! I've spent hours twiddling mine and I still cannot get any negative power.


Hoppy

[MileHigh]

Hey Harvey,

Well I don't visit this side that often - I punched in here on page 142, saw Mile Highs post regarding the 555 back there, (Sorry MH, your wrong about the 555 supply voltage messing with the timing), skimmed a couple of posts and realized I should just skip to the end.

Evidently we do need a current limiter on these timers
during this type of testing. I blew out my trusty 30 year old NE555 from 1980 tonight when the circuit went into aperiodic oscillation. The timer section was still clocking, but the output was hosed. It seemed to be tracking the discharge pin, no flipity floppity. This confirms my suspicions that resonant pulses are punching through the drain-gate capacitance at specific frequencies and routing through the output sink of the 555 and also making its way back to the reset transistor internally.

Also, MH - if you read the specs on the 555 you will find that the timing cap energy runs through the discharge pin which is only limited by case dissipation, nothing we are doing is pegging that.

I'll agree to split the difference with you on this one.  I see how the timing cap is discharged through an open-collector transistor inside the 555, so a flaky supply would not really affect that.  On the other hand, the timing cap is typically charged through the external Vcc power supply.  So certainly the timing for the charging portion is affected by the external trimpot, where the trimpot resistance is on the same order of size as the timing resistor itself.

The bottom line is that the external trimpot to the 555 power pin is simply wrong.  There is no logical reason for the trimpot resistor, in fact it is illogical, and I hope that Aaron removes it for future clips and others don't use it in their builds.  If a 555 fails in a circuit, you should look at each pin to see why that's happening.

Since I have your attention, and assuming that we get through this positive vs. negative micro-milliwatt debate, I would encourage all of the builders to build and test the Ainsley circuit in its vanilla configuration, no oscillation, just a regular pulse waveform switching the MOSFET on and off without any spurious oscillation to see if you can find over unity.  It should be easy to do, and easily repeatable.

This spurious oscillation business is almost never going to be the same between two different setups whereas the vanilla setups should be quite similar to one another.

Also Fuzzy, with all due respect, worrying about the ground is yet another Red Herring that is going to sap energy and confuse the builders.  It represents throwing another monkey wrench into the works and is pointless.  The ground for this circuit is the battery ground, plain and simple.  The grounding is a non issue.

Meanwhile, I don't think Aaron has responded to the 555 trimpot issue.

MileHigh  (Join the club! lol)

P.S.:

Cold War US Government instructions on how to build an elephant fallout shelter:

http://www.youtube.com/watch?v=GOcVkofa1AU

[fuzzytomcat]

Also Fuzzy, with all due respect, worrying about the ground is yet another Red Herring that is going to sap energy and confuse the builders.  It represents throwing another monkey wrench into the works and is pointless.  The ground for this circuit is the battery ground, plain and simple.  The grounding is a non issue.


MileHigh  (Join the club! lol)

P.S.:

Hey MH,

I would say anyone trying this type of experiment should have the equipment to check whats coming out the wall your plugging your testing equipment and replication into ..... every instance is different and should never be overlooked especially when data recording is taking place. My option to resolve 99% of my problems is using a UPS or "Uninterruptible power supply"

http://en.wikipedia.org/wiki/Uninterruptible_power_supply

It works very nicely and is inexpensive per say

Fuzzy 

[fuzzytomcat]

The ground for this circuit is the battery ground, plain and simple.  The grounding is a non issue.

This statement is half true .... are not the oscilloscope "probe" grounds internally connected (bonded) inside the oscilloscope to the ground on the oscilloscopes 115 Volt power connector? This connector plugs into a receptacle where the neutral and ground in a United States 115 volt electrical system are bonded together ...... with inductive and resistive loads ..... this is the issue for some

Fuzzy