Embedded programs engineer Juan Flores has constructed a compact little board designed to make it simpler so as to add solar energy to your subsequent construct: the Photo voltaic Buck-Increase module.
“This challenge is a module that permits charging a Li-Po [Lithium Polymer] battery from two completely different power sources and gives a continuing output voltage impartial of the battery voltage, with minimal losses to make sure long-lasting operation in low-power purposes,” Flores explains. “It really works accurately with a photo voltaic panel, therefore its title.”
The compact board, which has a USB Sort-C connector at one finish, a battery connector on the prime, voltage output pins on the different finish, and a screw terminal for a photo voltaic panel on the backside, is constructed round two core units: the Consonance Electronics CN3063 lithium-polymer charging chip and a Texas Devices TPS63020 for dealing with voltage regulation on the output.
“This element could be very attention-grabbing,” Flores writes of the TPS63020, “because it permits configuring the output voltage based mostly on the voltage divider related to the suggestions pin (pin 3). The datasheet already offers some values for a 3.3V output, which is what I used to be initially in search of, however we may principally depart the 180k resistor and alter the 1M resistor to acquire completely different voltages, equivalent to changing the 1M resistor (R4) with a 1.6M one for a 5V output.”
The charging circuit acts as an N-type MOSFET with the drain related to the photo voltaic panel and the gate to the USB enter: if energy is current on the USB connector it’s robotically used to cost the battery, and if not the photo voltaic panel is used as an alternative.
Flores has launched KiCad challenge information for others to construct their very own photo voltaic modules. (📷: Juan Flores)
“It might work with photo voltaic panels from 4.5V to 6V, however ideally, a most of 5V must be used,” Flores writes, for the straightforward purpose {that a} photo voltaic output larger than 5V would take precedence over the USB connection.
“Additionally, the charging velocity is dependent upon the panel’s energy. The one I exploit is 0.2W at 5V, that means it generates 40mAh at full efficiency, so it might take 10 hours in full solar to cost a battery just like the one in [my] video (500mAh).”
The complete challenge write-up is accessible on Hackaday.io, with KiCad challenge information and schematics obtainable on GitHub underneath an unspecified license.