Testing the TK Tar Baby

[TinselKoala]

Leon - that's so much better than TK.  Is that your name?  I've always wondered.

(snip irrelevant innuendo)

Rosie Pose

No, Rosie Poser. You can call me Deckard, if you like.

But you won't be any closer to the truth than you usually are.

[TinselKoala]

@PW:
What do you think of these scope traces shown here?

http://newlightondarkenergy.blogspot.com/2011/03/84-10-days-to-go-and-yet-more-surprises.html

And for Poynty et al.  There is no question that - on this new setting - there is absolutely NO energy being passed from the battery to the source rail during the 'on' period of the duty cycle.  I am reasonably satisfied that it's due to the resistance offered at the FET and to that variation that we have on this circuit.

You know... for once I do believe she's right. A blown mosfet offers a pretty high resistance all right, which would account for why it's not turning on and passing current when it receives that positive 12 volt pulse at its gate during the ON period of the duty cycle.

[picowatt]

@PW:
What do you think of these scope traces shown here?

http://newlightondarkenergy.blogspot.com/2011/03/84-10-days-to-go-and-yet-more-surprises.html

You know... for once I do believe she's right. A blown mosfet offers a pretty high resistance all right, which would account for why it's not turning on and passing current when it receives that positive 12 volt pulse at its gate during the ON period of the duty cycle.

TK,

The first and last look like FIG 3 and FIG 4 in the first paper with the same Q1 issue (same date/time stamp as well).  RA's circuit is different than yours.  Her Q1 works in some 'scope captures, and not so much in others.  Yours always works, unless you disconnect or damage your Q1.  I see she continues to cling to the same "Q2 can't pass current therefore its a marvelous mystery" claim. 

PW

[TinselKoala]

@PW: It's the white pegboard, I just know it.

By the way, when you were teaching your kids to solder, did they ever damage any components from overheating them? I know I certainly have, especially when I was using my nice Craftsman soldering gun at 150 Watts.  Bzzzzz!
It's nice to have a modern temperature-regulated soldering iron these days, and clipon heatsinks and all that stuff, especially when soldering directly to the leads of mosfets.  Did you know that mosfets can actually be damaged by static electricity, too? Golly.

Sigh. I sure wish I had a digital oscilloscope, so that I could make screenshots like this one.

[picowatt]

@PW: It's the white pegboard, I just know it.

By the way, when you were teaching your kids to solder, did they ever damage any components from overheating them? I know I certainly have, especially when I was using my nice Craftsman soldering gun at 150 Watts.  Bzzzzz!
It's nice to have a modern temperature-regulated soldering iron these days, and clipon heatsinks and all that stuff, especially when soldering directly to the leads of mosfets.  Did you know that mosfets can actually be damaged by static electricity, too? Golly.

Sigh. I sure wish I had a digital oscilloscope, so that I could make screenshots like this one.

TK,

Believe it or not, no.  But that was using flea clips with thru hole parts, and I always made them wipe on the damp sponge and tin the tip first, trying to instill good habits.  I also used TC202 temp controlled stations (they use Curie point in tip metal with magnetic switch).  Very reliable.  I still have three of those stations and some electronic controlled finer tipped versions for SMT work.

Oh c'mon, you don't need a DSO to duplicate that... well, on second thought, maybe...

(throw that gun aside and break out the torch)

PW