LEDs oscillate in stored energy LC circuit.

Stored energy in large coil oscillates; flashes LEDs. The LC(R) Oscillations demonstration uses a 6VDC battery, a large inductor with an iron core (L=390mH) in parallel with a 1000uF capacitor, a 330 ohm resistor and 2 small opposing diodes (total circuit R is roughly 5 ohms). With such small resistance, the oscillation is underdamped and it is possible to see a few flashes as peak currents oscillate through the diodes. To operate: Turn on the 6VDC battery; On the back of the circuit display there is a black box with a momentary switch mounted on top. The switch is wired normally open. Push and hold the button to charge the circuit; one of the diodes will be lit. Release the button; you should expect the diodes to flash, back and forth, for about 1-2 seconds; plenty of flashes to show the effect.
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Demo Diagram: