Mysterious Resonant Circuit

[EMdevices]

A MYSTERIOUS RESONANT CIRCUIT

by EMdevices,  July 23, 2008


   By accident I discovered a very interesting resonating circuit.  All it took was the "small" mistake of reversing the polarity on the transistor trigger coil as I was trying to reconfigure my trusted old Blocking oscillator circuit.

I have explored this circuit some more and found out how to control the resonant frequency, and why it resonates so high.  It seems the breadboard internal capacitance is playing a part, and so I added more capacitance on a spare winding to control the frequency. 

Here's a few pictures and the scope shots:

Figure 1
Image of my breadboard circuit.  Very simple, some of you have seen it before in another thread.

Figure 2
Schematic of the circuit.  All windings are on the toroid core, obviously. Not sure what the capacitor values are.

Figure 3
This is the voltage waveform at the Collector of the NPN.   Notice something strange, which I never seen before.  Notice that the voltage is actually NEGATIVE when the NPN is "triggered" on   (you'll realize this from next figure) Frequency is about 20 MHz.

Figure 4
This is the Base voltage.  Notice the shape of the waveform is similar to the collector but inverted.  This is the mistake I made, but now it seems fortunate I made it. 

Figure 5
This is the output across the 150 ohms resistor.  It heats up pretty fast.   Transistor is cool on the other hand.  These tiny Radio Shack transistors have never controled so much power without frying before.  Waveform is almost sinusoidal but not quite. Different values of capacitance up top, will change it a bit so it's almost sinusoidal.  The output power is almost 1 watt if one does a careful integration of this waveform.

Figure 6
I got the idea to scope the battery to see if there is anything unusual.  WOW !!!!   What the heck?   Now I don't trust my AMPERAGE measurements I did earlier, where it seemed I was drawing so little current  (40 mili Amps or less from the 8.5 Volt battery, so not even 0.4 watts as input, which would give OU performance to this circuit by a wide margin)  I need to work on isolating and filtering the power supply so I can have an accurate current measurement, so I'm not claiming OverUnity performance, just yet, so everybody just relax....

Figure 7
Another image of the breadboard from the other side.

EM

[pauldude000]

Interesting

Paul Andrulis

[EMdevices]

Ladies and Gentilemen,

I now firmly claim  OVERUNITY,  and wish to enter this circuit for the OVERUNITY PRIZE at this website  !!!


I've found an excellent way to smooth battery RF voltage fluctuations to where they are below 0.4 volts,  and the following modified circuit illustrates the modification.    (series L + C, when tuned have inpedance = 0 )

Also, I now have an almost perfect sinewave at the output, of 17.5 Volts Amplitude across the 150 ohm load resistor.

Here's the power calculations:

POWER IN  =  ( 8.2 Volts DC )  x  ( 0.1 Amp DC) = 0.82 watts

POWER OUT = ( 17.5 Volts AC) ^2 / ( 150 ohms)  / 2 = 1.02 watts

EXCESS POWER =  (1.02 - 0.82) / 0.82 = 0.24 = 24 % extra energy

COP = 1.02 / 0.82 = 1.24


At last !!!!!!!

EM

P.S.  I just sent a PM to Stefan to alert him.   The game is on, yepeeeeee !!!!,  I just hope 24 % extra energy is enough of a margin to make such a claim and have it varified.  I'll try to determine the exact capacitor values later tonight, and I'll post the exact waveforms as well.

[fritz]

a) how do you measure input current ?
b) whats mysterious about an oscillator with inductive coupled load and lc tank ?
rgds. !!!???!!!

[EMdevices]

a) how do you measure input current ?
b) whats mysterious about an oscillator with inductive coupled load and lc tank ?
rgds. !!!???!!!

a)   I measure the current with an ampmeter in series with the battery.   Reading is 0.1 amps  (Voltage measured across the battery is 8.2 volts,  both are DC measurements)

b)  The mystery comes about due to the polarity of the windings.  Look for the black dot on the coils, it tells which terminals have the same polarity when the flux is changing through the core.   In normal oscillators (like Armstrong, Blocking, etc..),  the trigger winding should be reversed from what I show, so that when the Base is (+) and current flows, the Collector can pump the resonant tank.  Also, notice the collector voltage waveform, notice it's  NEGATIVE when the NPN is on,  I sure haven't seen that before and I'm not too sure what the transistor is doing.  I'm sure it's internal parasitic capacitance playes a part.  Maybe even negative resistance is at work here, not too sure at this point.

Sincerely,

EM

P.S.   broli,  I see your posting below,  I plan on doing a loop back tonight, but I need to think it through make sure the voltage doesn't increase and burn things out.  In my mind that would be the ultimate proof of overunity.   I have not done any margin of error calculations yet.