Is joule thief circuit gets overunity?

[poynt99]

poynt99
Supose at a given instant of time the reacitve power is 10 volts and 0 amps while the real power is 1 volt and 1 amp. I think the scope will read 11 volts and 1 amp (11 watts) while the real power is actually only 1 watt. Am I doing this wrong?

Yes you are doing this wrong.

Look at the scope traces in my above post. How can you have more than one value for voltage or current at any particular instant of time?

You can't. There is only one voltage and one current. Their product is the power at that instant of time.

[xee2]

How can you have more than one value for voltage or current at any particular instant of time?

poynt99
In the example there is only one value of current (1 amp) and one value of voltage (11 volts) on the scope. Those values are the total current and total voltage the scope sees across the non-resistive load. For AC circuits, when the load is not a pure resistance the reactive components can add voltage without adding real power. Like I said, I have not thought this all through. But this is one of the things that I think needs more thought.

[poynt99]

poynt99
In the example there is only one value of current (1 amp) and one value of voltage (11 volts) on the scope. Those values are the total current and total voltage the scope sees across the non-resistive load. For AC circuits, when the load is not a pure resistance the reactive components can add voltage without adding real power. Like I said, I have not thought this all through. But this is one of the things that I think needs more thought.

In your example your total voltage and current consisted of two values added together. I am trying to tell you that there is no such thing. The values are simply what they are, nothing more nothing less.

Regardless if the voltage across a load is increased due to its reactance, when that voltage is multiplied against the current at that instant, the p(t) might be quite small, even though the voltage is higher.

Anyway, I have provided all the information you need, in a clear manner. It is up to you to study and try to understand it.

[xee2]

poynt99
Thanks for your help. You seem to be on top of this.  I was always taught to measure real power using a resistor, so I am always suspicious when that is not done. I am sure that if there are any problems you will spot them.

[ltseung888]

Some pleasaant surprise first.  This new batch from Shenzhen used toroids that are machine  wire-wounded.  The COP on board 70 jumped to -27.32.  I shall check on other boards.  With more boards at my disposal, I can try the two or more stage JT.  (Output of one becomes Input to another)  Preliminary tests were encouraging.  More on that later.

Now see the new scope shots - not all JTs are equal even though they all light up the LED!!!

Not all JTs can demonstrate OU - once they can, I call them FLEET...  That is why JT research is interesting...