The steps to convert a 5V solar panel to 12V are as follows:
1. Find an old cell phone charger (5V1A), simply replace a 12V Zener diode above the 5V output end, and the output will immediately become 12V DC.
2. I didn't have a 12V Zener diode on hand, so I found two 6V Zener diodes and passed them through the transfer switch when connected in parallel, the voltage was 6V, and during the dip. The switch was connected in series, it was 12V.
3. In order to increase the output current and stabilize the voltage, I connected a 400V60uf capacitor in parallel to the rectifier part and a 16V1000uf capacitor in parallel to the output end.