Do you have a meter in series with the cap to monitor current?it's charging very slow at 0.02 - 0.04 A, why?
Thanks.Boost converters don't normally have a lower output voltage than the input voltage. My guess would be there is unaccounted for resistance. Charging a capacitor always involves an R and a C. That internal resistance is designed to keep it from discharging an enormous amount of energy in a short period of time. That energy is:
\( \frac{1}{2}CV^2\;=\;1823\;\text {Joules} \)
That is the same amount of energy in a 500 Kg. block of steel traveling 2.7 meters/second slamming into a brick wall.
Be careful about connecting the power source directly to the capacitor. Without some device to limit the current an accidental discharge could be painful or perhaps fatal. Don't try to charge it too rapidly either. You want to be deliberate in the way you go about this. Folks will sometime use a light bulb for this purpose.Thanks.
Sorry I made a wrong name of it, it is BUCK step down.
I guess I need make adjustment on the CURRENT pot, which I didn't do.
Thank you.Be careful about connecting the power source directly to the capacitor. Without some device to limit the current an accidental discharge could be painful or perhaps fatal. Don't try to charge it too rapidly either. You want to be deliberate in the way you go about this. Folks will sometime use a light bulb for this purpose.
Any device to limit the current. An appropriately sized resistor is an obvious choice, but a garden variety light bulb is also an alternative.Thank you.
I am first time to deal with this, what device should I add between?
Best
Abd the light bulb has the added side effects of showing the state of charge.Any device to limit the current. An appropriately sized resistor is an obvious choice, but a garden variety light bulb is also an alternative.
It's not the shock, it is the amount of energy released in a short period of time. It is what happens to the package when that energy is released.That 500 Farad capacitor is requiring a whole lot of charge. Consider the time to charge a 500 Microfarad capacitor, (500 mfd=500x 10to the -6power farad. So your new capacitor is about 10,000 times larger. Another factor is that the effective series resistance (ESR) may not be small on your new capacitor.
One other thing is that a maximum voltage of 2.7 volts there is not much of a shock hazard at all. Short circuiting the capacitor is not advised, but that is quite different.
1 million times larger.So your new capacitor is about 10,000 times larger.
We seem to be having "orders of magnitude" problems. What could be the reason?1 million times larger.
Thanks.Do you have a meter in series with the cap to monitor current?
Probably the error was due to not being fully awake yet.We seem to be having "orders of magnitude" problems. What could be the reason?
Thanks.I use a current limited switching supply to charge my 100F capacitors. No, I would not want to slap one across my bench supply -why stress out either the bench supply of the cap?
View attachment 233915
View attachment 233916
This is the voltage across a 100F ultracap in millivolts vs time in seconds -about 700 ma as set by R2.
Thanks.Probably the error was due to not being fully awake yet.