Here we use Boost boost circuit, circuit is mainly composed of load R, diode D, switch tube T, inductor L, capacitor C, working principle is: when T conduction, D reverse deviation, solar cell charging for inductor L, when T off, D conduction, and load parallel capacitance C, inductor and solar cells for the load, so the voltage on the load without superposition output voltage, so the circuit boost role.Judging from equation 3-1, the voltage change of the Boost boost circuit is only related to the duty cycle, so the Vi relative to the maximum output power point can be found by adjusting the duty cycle D of the circuit.The schematic diagram is shown in Figure 3-19,