Rosemary Ainslie circuit demonstration on Saturday March 12th 2011

[i_ron]

Actually,

Rose's haphazard use of her loaned function generators is immaterial to the facts.

It is common sense that we should not be driving a high current output INTO our function generators. Perhaps there are those not familiar with how MOSFETs or transistor circuits work in general, and they do not see the MOSFET Source as a high current output, but I assure you, it can be, and in this case it is.

Why is the original circuit (see below) shown with the CSR (current-sensing resistor) located in the MOSFET Source leg? Note also that the function generator is connected to the MOSFET Gate only, not the MOSFET Source.

.99

.99,

I don't see it as a problem, this function generator thing, any FG I have seen has some form of a high current output buffer and as such is a SOURCE, not a SINK. The circuit topology precludes any reverse flow other than the amount designed into the buffer.

BUT, what you guys are missing here is a major major bomb shell. Forget about Rshunt, the circuit is a circle and Rshunt can go anywhere in the circle as long as you use isolated ground measuring techniques.

What everybody has missed is the schematic calls out 6 batteries and only 5 are used in the vid!!! Get it??? 6 on the drawing and only 5 used, wow

And to top it off... nearly dead flat batteries, gosh!  5 fully charged batteries would read 63,5 volts and just look at the voltage in the video.

The duplicity of this must rank up there with the second (or third) killing of osama or at the very least obama's fake birth certificate!!

Geez,  someone needs to start a forum for this!

Ron (tongue in cheek, mostly cheek...)

[Groundloop]

Here is a little circuit I did draw just now. It can be used as a half bridge
switch if one choose to use a double power supply (+V to COM to -V) or
just use the top part as a single switch. In that case the load should be
in series with the plus rail. Analog opto couplers can be ready bought or
home made by using one Light Depended Resistor (LDR) together with
a Ultra Bright Light Emitting Diode (UBLED) inside a light insulated box.

GL.

[poynt99]

I don't see it as a problem, this function generator thing, any FG I have seen has some form of a high current output buffer and as such is a SOURCE, not a SINK. The circuit topology precludes any reverse flow other than the amount designed into the buffer.

Actually, any FG with an output that is capable of swinging both positive and negative is both a SOURCE AND SINK respectively. We know that the FG Rose was/is using is capable of a negative swing. In fact, it is only when the FG output is negative that the oscillation occurs, so we can conclude from this that the FG is providing a path to its internal negative supply rail, most likely through the PNP transistor of a complementary push-pull output stage, or similar.

BUT, what you guys are missing here is a major major bomb shell. Forget about Rshunt, the circuit is a circle and Rshunt can go anywhere in the circle as long as you use isolated ground measuring techniques.

I am aware of where the CSR can go and how to measure across it. However, the problem is that the CSR was not in the proper location to measure battery current, and Rose recently admitted to this fact. Did you not read that?

What everybody has missed is the schematic calls out 6 batteries and only 5 are used in the vid!!! Get it??? 6 on the drawing and only 5 used, wow

Is there a significance to this? I was aware of the differeing battery voltages btw. They actually have used 5 AND 6 batteries in two slightly different tests. Did you watch the demonstration video?

And to top it off... nearly dead flat batteries, gosh!  5 fully charged batteries would read 63,5 volts and just look at the voltage in the video.

60V, indeed. That would equate to about 12V each battery. It would be premature to assume that these batteries are "nearly dead flat" without knowing the particulars of these batteries.

Ron (tongue in cheek, mostly cheek...)

Careful with that cheek; you'll probably still need it for a while.

.99

[i_ron]

Is there a significance to this?
.99

Yes, it is called humor. It points out some of the "how many fairies can dance on the head of a pin" arguments in these threads, but of course one needs a sense of humor to begin with.

Ron

[i_ron]

Possible sources for purchasing the IRFPG50:

http://www.questcomp.com/QuestDetailsAll.aspx?pn=IRFPG50&pnid=91660&stock=YesOnly

http://www.ibselectronics.com/search_r.asp?mfgpn=IRFPG50

http://export.farnell.com/_/dp/1704010

.99

Just a report on the first two links...

Quest have them for $3 each for 3, but they have a $25 dollar minimum charge. In an effort to get the order up to that I looked up some IL710's,
wow, $10 each. and "ships in five days"  Digikey have them for less than $3.
Same with the rest of the things I looked up, way over priced and long delivery times.

Next I tried ibs, $17 something for three but $25 dollar delivery (snail mail) or $61 for bandit delivery.

So ended up with an order to Digikey for the STP16NK60Z and some other supplies.

Ron