Mysterious Resonant Circuit

[xee]

@ EMdevices

If the load resistor was 190 ohms instead of 150 ohms due to heating, then you would no longer be over unity:

watts out = (0.707*17.5)^2/190  = 0.80568

[poynt99]

good point xee about th heating and change of resistance.

EMD, suggest using at least a 10W power resistor in there. if  the transistor doesn't get too hot let it run for a bit and  check the load resistance (disconnect it from the circuit) right after you take your voltage measurement.

[willitwork]

Nice work EMD,

To fully confirm OU, I suggest:

First: Put a large electrolytic cap - 10,000 microfarad or so parallel to the battery.
Second: Put a bridge rectifier where the 150 ohm load is, (This will require disconnecting the ground connected side of the coil.
Third: Use the output of the bridge rectifier to charge the electrolytic - essentially powering the device
Fourth: Start the oscillator with the battery then remove the battery.

[aleks]

If the load resistor was 190 ohms instead of 150 ohms due to heating, then you would no longer be over unity:

Just make sure resistance does not drop It may drop with higher temperature as well, depending on resistor's material.

[aleks]

I see my Voltage is a bit smaller more like 7 volts.

Looks like 6.25V, to be more exact.