Welcome to my (obviously homemade) site. I am an old electronics buff ever since
I first strung a long wire antenna out my bedroom window as a small boy and hooked it to
the Heathkit crystal radio detector I got for Christmas from my uncle.
I plan to slowly add topics, schematics and discussions of the many interesting projects
since then that have captured my imagination.
An ultrasonic driver.
Lake Tahoe at dawn.
The Olson 40 on San Pablo Bay.
This is my homemade direct conversion Single Sideband receiver, soon to include the
exciter and R.F. Amp, allowing full operation on 40 meters here in the North Tahoe area.
My antenna is a vertically polorized
dipole with the top being 90 feet up a beutiful Lodgepole pine in my backyard.
This photo is the final R.F. power amplifier using gold alloy monster transistors
which, after some custom tuning, should deliver several hundred watts output.
Here is a sonicator, showing 2 transducers facing directly at each other with the small
gap between them filled with water being hammered from both sides, in phase, with significant
cavitation of the water occuring. This particular demonstrator is made of plexiglass, not quartz tubing.
The small hole in the plexiglass sleave is seen near the top to fill and drain the sonicator.
Photons are emitted from that small space which contains the water.
The following circuit schematic is a very efficient and powerful little oscillator that can deliver
significant wattage to a piezoelectric load, in this case 2 such loads are being driven in parallel.
This particular circuit makes use of a complimentary pair of power MOSFET's to switch the 60 volt rail
at a half an ampere of current or so depending on the load impedance of the transducers.
This circuit is of the type of circuit known as a voltage follower, In this case a single stage
complimentary, common drain voltage follower. Although marked with the N.T.E. numbers shown, I
have since found a better pair of MOSFET's, the N.T.E. # 2374 N-channel, and N.T.E # 2371 P-channel
which have greater gain but more input capacitance, which only means that less inductance is required
in the feedback transformer, for a given frequency.
The output point is where
Q1 and Q2's source leads are connected and that point "follows" the input point where
C4 and C5 are connected. This circuit has essentially unity voltage gain but enormous current gain
due to the very high input impedance and small proportion of energy needed to drive this type
of insulated gate FET switch. The voltage signal derived from the current doughnut T1 alternately
drives the 2 gate leads first positive with respect to their sources then negative, thereby bringing
Q1 into conduction when the input point is driven positive with respect to the output point
then switching Q1 off and bringing Q2 into conduction when the input is driven negative.
The voltage divider formed by R1, D3, (a 6.8 volt zener) and R3 keeps about 3.4 volts (half the 6.8)
across each gate source junction, just enough to bias them a tiny bit into conduction setting up
a small zero signal idleing current to get things rolling. Not shown is the power transformer providing
48 volts ac to the bridge rectifier, producing about a 60 volt dc rail. A transformer should be used
for safety and isolation purposes. The filter formed by C 1,2,3 and L1, L2 is a simple low loss
unregulated inductive capacitive variety. The use of quality high permeability ferrite toroids will
provide almost lossless conversion from the ac input to the dc rail.
The current doughnut transformer T1 in this case is a .37 inch diameter toroid made by the Amidon
company. The alloy of this toroid is their "43" material exhibiting good Q from 10khz to 1 mhz
The secondary is 14 turns evenly spaced around the perimeter and the primary is simply a conductor
which goes in one side of the doughnut hole and out the other side.
This current doughnut creates a potential on the secondary winding proportional to the current
passing through the primary on it's way to the load. The ideal load for an oscillator like this is a
pure resistance, then the current to the load is completely in phase with the applied voltage from
the output MOSFET's and reactive energy reflected back from the load is minimal, so heating of the
MOSFETS is minimal and efficiency to the load is very high. However, these piezoelectric transducers
are allways a far cry from pure resistive loads. On the contrary they are highly reactive and
produce significant reflected harmonic energy back into the output MOSFETS creating unwanted heating
and poorer efficiency. That is the reality which must be lived with unfortunately. I hope to experiment
and learn the best way to match output impedances to the load better which may bring the efficiency up considerably.
This site is a work in progress regarding the phenomenon of sonoluminescence.
It is created by Kip Wallace in an effort to explore this
Any response to this site can be sent to Kip Wallace firstname.lastname@example.org
I have set the background color of this start page to the approximate
color of the light of sonoluminescence as revealed by photographic time exposures
made with film of known chromatic spectral response.
Sort of a bluey green.
The following observations and comments regarding sonoluminescence
are mine alone and I make no specific claims or conclusions concerning the subject.
To those who may be visiting this site and have not been introduced to this
subject, here is a brief introduction to sonoluminescence.
My observations are with water only. There are references to sonoluminescence
occuring in other liquids such as acetone or alcohol. This may be true. I have no experience
with substances other than water.
What is sonoluminescence ?
When a container of water of non specific volume is subjected to severe physical stress
on a rythmic basis (typically in the form of ultrasonic bombardment) it causes that water
to cavitate. Cavitation is a commonplace occurance in everyday life. The propeller in a
boat is damaged (pitted) by the violence of the process.
Cavitation can be characterised as a brief, fleeting separation or void created in
a liquid by the application of rythmic stress of a magnitude sufficient to overcome the
force of 1 atmosphere of ambient pressure holding that volume of water in it's
liquid (uncavitated) state, causing many voids or "cavitation bubbles" to form in that water.
Many of these "bubbles" form, grow, then collapse violently with every cycle of the
applied ultrasonic energy (many thousands of times per second).
During the collapse phase of the bubble's life, powerful compressional forces exist.
Powerful enough to cause the emision of photons.
As the bubble is pulled into existance during the low pressure (growth) phase of the acoustic cycle,
water molecules migrate into the volume of the bubble as it expands (accretion phase).
Because this growth phase is occuring against the pressure of 1 atmosphere, the collapse
phase which follows is far more brief and intense because it has been "pre loaded" like a spring, with
all the energy required to pull it into existence.
The ensuing collapse phase, sudden and violent, traps the water molecules in a super compressor which
super heats and dissociates the oxygen from the hydrogen, generating temperatures needed to emit
photons in the green portion of the visible spectrum. (10,000 degrees or so)
The spectrum of these photons is quite narrow and occurs mostly in the green portion of the
visible spectrum. It has been suggested that simply the orbital energy level of the electrons
in one or more of the substances in the sonicator will emit photons as they hop from one energy
level to another as the pressure in the bubble changes rapidly by the applied ultrasonic energy.
My experiments were made with a sonicator of transparent quartz tubing allowing easy viewing
of these photons with the unaided eye, providing that one allows one's eyes to "adjust to the dark"
prior to viewing.
A photomultiplier (or counter) can also be employed, along with various color filters, to determine
the spectrum of the emision.