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Hello Tesla builders,
Here is a design overview for critique... maybe experience in the TC
list will save me a buck or two. Comment on design overview for me
please. . .
The design is intended to drive a dipole loop in two halves such that it
oscillates beginning at the 2nd harmonic (typically --but this case is a
non-harmonic experiment).
I want to buy the new eGaN transistors for a try-out. They are nearly
an ideal transistor, with tremendous slew rates. (About 12 volt skew per
nanosecond.) They conduct hundreds of amps in short bursts, up to 200
Volts. They do not suffer from thermal-runaway, because they conduct
less when warm. This allows them to be ganged with no runaway protection
needed.
Can anyone share any experience with eGaN transistors? Did someone drive
a football coil with these, I think David Thompson shared.
A random ring amp pushed into more randomness with half-switching... is
the goal.
I plan on using a very small breakout board, and soldering the eGaN
surface-mount passivated-die transistor on the breakout board and that
soldered directly to a copper dipole resonator, then bury the transistor
and breakout board under thermal epoxy, so the copper resonator element
becomes also the heat sink.
Mounting directly on the resonator is to reduce impedance for maximum
delta-B possible. Each semicircle loop of the resonator is driven
separately, so the loop is two independently switched halves.
The two halves are switched in a flip-flop circuit. This circuit will
connect with two more flip-flop-driven semicircle pairs to create a
3-phase ring amplifier of power-flip-flops flipping 'n' flopping very
randomly.
The cross-over 'X' of the common flip-flop schematic in the circuit is
occupied by the pair of semicircular loop-halves.
The device is a study in the random profile of the inherently random
ring oscillator gone wild.
I read in recent research on randomly driving transformers that more
wattage can be put through a random pulse drive into a coil, than would
this coil accept if it is pushed into harmonic operation.
What I hope is that there will not be a standing voltage accumulate as
do resonant coils, helping the RF interference stay low <--- I assume!
Comments???
BTW: the transistors are mounted on the semicircles at the ends, so they
operate near what would be a resonant node of the 2nd harmonic. Testing
will validate the design.
Any suggestions before I burn through some money?
Thank you for sharing your hard-earned know-hows.
Don
Quicky: The quantum-enhanced gallium nitride transistor is an FET. It
is enhanced by a crystal layer over the FET gate layer. The added layer
is a dissimilar crystal. Electrons hang out at the discontinuities of
the crystal junction --which is the FET gate. Therefore, population
time of the gate region is non--existent, because the gate is already
populated by electrons at the discontinuities. This transistor was
conceived by a post-grad student in 2010. Early packaged devices sold
to military budgets around 250 USD per package. Passivated die
transistors with solder-bumps ready for reflow-soldering (with hot air)
onto the tiniest circuit landing pads used in the industry. The
passivated-die transistors are five or ten bucks each. The power
conversion efficiencies have been pushed to 99% with these near perfect
transistors. Oh yeah... the on-resistance is around ten milliohms! And
more or less on some models.
FYI: This circuit will be tested for what I'm after only after I build
some analysis circuitry to capture the variation in the edge jitter.
Each cycle period duration is captured as a 16-bit number, for
post-measurement spreadsheet analysis or such.