Joule Thief - What's The Frequency, Kenneth? (4K)

[@gumpster6]

Interesting video - thanks for sharing. Did you have a x10 probe on there? The Vpp was showing around 200-300mV most of the time and the LED shouldn't be lit at that voltage.

[@tsbrownie]

Thank you. Good question. Yes probe was set to 10x.

[@gumpster6]

@@tsbrownie That makes sense - thanks.

[@craignehring]

You always have some interesting videos

[@tsbrownie]

Thank you for that.

[@t1d100]

Yes, a very interesting investigating. Thank you.

[@tsbrownie]

Glad you enjoyed it.

[@andrewel5383]

What happens if you add a ceramic capacitor across the coil connect from power to collector? Would that possibly form an LC resonant tank circuit? If so would that cause said joule thief to oscillate at said frequency?

[@tsbrownie]

Remembering that all components (even a straight wire) has 3 properties: resistance, capacitance and inductance, adding capacitance to the natural capacitance of the inductor would change the frequency at which it resonates, mostly likely lowering it.

[@andrewel5383]

@@tsbrownie thank you! Would it be possible to raise the resonant frequency? Let’s say to 3mhz? Like if a capacitor which was lower than the parasitic capacitance was hooked up

[@tsbrownie]

@@andrewel5383 Yes, lower inductance and capacitance gives you higher frequency. So you need to use a higher frequency toroid coil and fewer turns.

[@andrewel5383]

@@tsbrownie okay thank you!!