Joule Thief: Less Current with Load Connected than with Disconnected

Here I demonstrate that the JT Testbed, using a PNP transistor configuration, draws LESS, or about the same, current when the 24 LED load is CONNECTED than it does when the load is DISCONNECTED.

The voltmeter is set to the 200 mV range and is monitoring the voltage drop across a 1 Ohm current-viewing resistor in series with the positive battery supply, so the reading of the voltmeter in mV translates directly to mA of current by Ohm’s Law I = V/R. The load bank is an array of white LEDs from a Harbor Freight flashlight, rewired so that instead of all 24 in parallel, it is 12 parallel groups of 2 series LEDs. The AAA battery is fairly depleted, showing less than 1.3 v unloaded and a bit less than 1.2 v while running the JT.

Many people see results like these from various circuits using wound inductors of various configurations, and they think they are seeing something incredible, remarkable, even to the point of claiming “free energy” to the load. But what does it _really_ mean? It means that the circuit is slightly less _inefficient_ when the load is connected, that’s all.

Would an oscilloscope give the same readings? The JT is a pulsed inductor circuit and the accuracy of the meter in this circumstance could, and should, be questioned. Many people, however, use similar DMMs when they are measuring similar circuits and drawing their “OU” conclusions from them.

It is rare to see an oscilloscope, properly used, by someone who then goes on to claim “overunity” from their measured circuit. Quite rare. Even rarer is the use of a proper power analyzer in testing such circuits. Why? I know why… and so do you.

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