Magnetic Resonance Amplifier 4: Ferrite Core Without Magnets

Please watch the first three videos first. Schematics and further explanations are found in them.

Here I’ve made another transformer using half of a TV CRT horizontal deflection yoke ferrite. I wound it with 98 turns + 98 turns (bifilar, two strands at once) of #27 magnet wire.

Sine wave input from the F43 Function Generator is kept well below 5 volts p-p. The LEDs on the input and output sides are identical, from the same batch of 10,000 mcd, 2.2 v, 20 mA LEDs from SparkFun.

Using the measured values for the inductance of the ferrite-cored primary, and the capacitance of the piezo element used, I calculated the resonant frequency of the series LC tank to be about 22.95 kHz. The measured value in the video turned out to be around 23.9 kHz or so…. a very good agreement with theory. When I make the current measurements of this setup I will probably be able to refine that measurement somewhat.

The last frame of the video shows the screenshot from the calculator at

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