Rosemary Ainslie Circuit Demonstration, June 1 2013

[TinselKoala]

TK,

Didn't you do a video in the past where only Q2 was installed and oscillating (i.e., with Q1 pulled)?

PW

Several times.
Here's the most recent one, from last week.
http://www.youtube.com/watch?v=nbkpQQvuP2I

[picowatt]

Several times.
Here's the most recent one, from last week.
http://www.youtube.com/watch?v=nbkpQQvuP2I

TK,

So, in your video, even with Q1 removed from the circuit entirely, at around 9:34, one can see that the Q2 portion of the circuit continues to oscillate.  Moreover, the degree of clamping on the positive portion of the oscillation waveform on the CSR trace looks closer to FIG3 than it did when Q1 was installed.

With Q1 installed correctly and functioning properly, your waveforms look very much like FIG 5.

Point being, merely showing that the Q2 portion of the circuit continues oscillating when there is no observed current flow thru Q1 is no proof whatsoever that Q1 is functional or connected properly.

In her upcoming video, she must show that +12 volts is being applied to the gate of Q1 as she now agrees that FIG3 indicates.  She must also show that Q1 is connected properly as per the schematic.  She must also show that during the time that +12volts is being applied to the gate of the properly connected Q1 that there is no current flow observed via the CSR trace.

Short of attempts at trickery such as using AC coupling, use of a faulty MOSFET, or connecting Q1 not as depicted in the schematic (reversing the Q1 source and drain legs, intentionally not connecting a terminal, etc), she cannot duplicate FIG3.   

Applying +12 volts to the gate of a functioning Q1, connected as per the schematic, MUST turn Q1 on and produce a waveform similar to FIG5, wherein current flow is indicated by the CSR trace when a positive voltage is applied to the gate of Q1.

At least, for now, she has finally agreed that we are reading her scope capture correctly and that +12 volts is indeed being applied to the gate of Q1 in FIG3 and that Q1 is not turning on.   



If she believes FIG3 is correct, I wonder how she would then explain the observed current flow thru Q1 in FIG5 when only +6volts or so is applied to the gate of Q1...


PW

[picowatt]

Her latest layout.

.99,

When do you expect to have your replication of her circuit up and runnig?

It would be interesting to see if there is any observed difference in the clamping of the waveform at the CSR when Q1 is/is not in the circuit as in TK's video.  That may offer an additional clue as to whether Q1 is installed properly in her upcoming attempt to duplicate FIG3.

PW

[picowatt]

Hopefully she has changed her mind about doing a "live only" demo this Saturday.  Posting it on YT would allow her "evidence" to reach a much greater audience in differing time zones.

Does anyone know when the show is supposed to begin?

PW

[TinselKoala]

Wouldn't it be hilarious if her heating element, which appears to be something like an RV water heater element, had a thermal limit fuse in it?