I was motivated with this video and want to add arduino brains to this simple construction.
My plan is to use 500Farad super capacitor like in video and IRLB3034 mosfets in parallel that are controlled by arduino, that can generate sequence of impulses: 1-3 impulse, 50ms-500ms each.
I'm really new in electronics and mosfets, so sorry for any stupid questions.
As far as I understand, I need to open mosfet really fast. LRLD3034 is low power mosfet, and can be controlled directly from arduino, but what about open speed? Do I have to use some special driver or some capacitor for quickly charge/discharge gate?
The ESR(effective serial resistance) of your capacitors will severely limit the discharge rate of the capacitors. Please check the data sheets for your capacitors.
You need a MOSFET driver, and of course MOSFETs capable of handling 5-10X the maximum current expected.
With a 2.7V, 1 milliOhm ESR ultracap, that could be as much as 2700 Amperes. Circuit board traces literally explode at very high currents, so it should be an exciting project.
WAIT! That circuit's completely wrong, the cap and its supply are inverted - the cap +ve needs to go
to the MOSFET drains.
Also the DC-DC convertor is drawn left<->right flipped, the output leads should go the cap.
Also there needs to be a current limiting resistor between the converter and the cap.
This circuit also requires that the DC-DC converter charging the cap is isolated / floating.
Incidentally I'd use gate-driver chip to switch a very high power load with MOSFETs.
A thyristor is traditionally used for such an application, as they are available rated for very high currents
(I have a 9000A pulse-rated hockey-puck for instance).
With a thyristor to switch the cap, you'd need to separately switch the power supply off to allow
the thyristor to reset.
Thyristors have a forward voltage rather than an on-resistance, so dissipation scales with current,
rather than current-squared with MOSFETs.
