Often small electronics projects don’t need lots of power, they perhaps only need a tiny bit of power infrequently. It can often seem overkill to have a large battery permanently tethered to a project that you might only power on every now and again. We’ve even questioned ourselves about building a charge controller for some simple sensors that only needed an occasional manual check. This Hand Cranked Energy Harvesting Board could be a really useful and sustainable solution to these types of projects.
It combines what looks like one of the N20 style metal geared DC motors set up as a generator to feed into an onboard 7.5V 0.5F supercapacitor. Watching the video on the product page it appears to take around 25 to 30 turns of the small crank handle to fill the supercapacitor if it’s completely discharged. Once charged to 3.3V, the onboard LTC3588-1 IC enables the power output via the Vout pin. The output voltage on the Vout pin is switchable between 4 voltages: 1.8V, 2.5V, 3.3V and 3.6V. This is achieved by setting two pairs of jumper pins accordingly.
Finally, there are 2 M3 mount holes on the PCB which can be used to mount the device to a support structure. We can imagine building this into a nice small case with some kind of barrel connector output for a super portable pocket power supply!