I have an energy harvester that generates impulses at frequency as low as 25Hz. Each impulse has a positive and negative parts. The width of each impulse is ~8ms (positive+negative). The PTP amplitude is ~5V. I can use a bridge rectifier but in order to fully rectify the signal I'll need a very large capacitor, something I would like to avoid because of size and weight.
Is there a suitable PM that can handle such an input?
After the bridge rectifier, you may want to consider the buck-boost solutions that we have. Please try to check this link: https://www.analog.com/en/parametricsearch/11503#/p5362=Buck-Boost
If the link won't work, please search in ADI website these generics: LTC3119, LTC3106, LTC3331, LT8490, LTC3129.
I assume you mean just rectifying bridge, without a capacitor. My concern is that the energy is in a form of impulse with relative large time in-between. Can the buck-boost solution handle such large time between impulses?
I assume you refer to a bridge without smoothing capacitor. Can these buck-boost solutions handle the large time between impulses?
I think that you will still need bit of capacitance after the bridge rectifier.
Thank you Fil,
If the frequency is 25Hz and the matched resistance is say ~20 ohm then for 10% ripple the capacitor is ~20mF. These are typically super-capacitor. Do they behave the same as standard capacitors?
If I understand what you are saying, we don't need a 10% smoothness at the input to the PM in order to get stable voltage at the output of the PM. Maybe 30% ripple is still good enough. Is this what you have in mind?
The ripple should be able to go by how much the buck-boost can take as low voltage as possible. You have to check that when the voltage goes to minimum, the current goes high & rating of the parts are still ok.