1、Project background
Due to limited capacity, the batteries of portable electronic devices cannot meet long-term electricity needs, leading to the emergence of mobile power sources. Mobile power supply is a portable charger that integrates power supply and charging functions, which can charge or standby power electronic devices such as mobile phones and tablets anytime and anywhere. The battery in a mobile power supply is also limited, and when the battery is depleted and cannot be charged, the mobile power supply cannot function. Emergency electronic devices on the market have shortcomings such as single functionality and slow power generation speed. In response to these shortcomings, I have decided to invent a multifunctional emergency power supply. It has a fast power generation speed and can not only be used for charging and lighting, but also for igniting fires. It can receive information during special periods such as natural disasters.
2、Basic Principles
By turning the handle, the user drives the variable speed generator to generate AC power, which is then stabilized and stored by the rectifier module. It can be used for speakers, LED lights, igniters, and USB ports.
3、Production of works
（1） Prepare accessories
According to the design requirements, I have prepared accessories such as handle, gearbox, three-phase generator, three-phase rectifier bridge stack, DC digital voltmeter, Farad capacitor bank, voltage stabilizing module, sound receiving module, antenna, speaker, lock button, self reset button, screw, insulation column, wire, electrical board, LED light board, heating element, USB2.0 interface, etc.
（2） Production process
1) Cut 6 electric wooden boards using a carving machine as the shell of an emergency multifunctional power supply. The electric wooden boards come in three sizes from small to large. Then cut holes on the electric wood board for installing modules, speakers, buttons, and other accessories.
2) Drill 2 screw holes on each of the 4 sides and the middle of the smallest sized electric wooden board, with the sides being longer
The screw hole on the edge is 2 cm away from the edge, and the screw hole on the short edge is 4 cm away from the edge. Next, align and drill holes on the four sides of the other four electric wooden boards approximately 0.5 cm away from the edges with the screw holes on the side of the front electric wooden board.
3) After drilling, install screws into the screw holes. Assemble the outer shell of the multifunctional emergency power supply with an electric wooden board, leaving a back cover for installation.
4) Install the handle, gearbox, three-phase generator, Farad capacitor bank and fix them in the box. Install the audio module, antenna, button, LED light board, DC digital voltmeter, speaker, etc. in the corresponding holes cut in the first step and fix them.
5) According to the schematic diagram of the work, wire and connect it properly.
4、Debugging
I first check if the wiring is correct and firm, check if the gearbox is flexible and add lubricating oil, and turn the handle to see if the voltmeter shows. Connect the multimeter to the output terminal of the voltage regulator module, use a small flat screwdriver to turn the blue adjustable resistor, adjust the voltage displayed on the multimeter to 5 V. Then press the “Radio” button to display the received frequency, pull out the antenna, press the “Search” button to change the received frequency, rotate the antenna direction to achieve the best received signal and clear and loud sound.
Next, insert a USB detector into the USB2 interface to check if the voltage polarity is correct, and press the LED button to check if the LED light function is normal. Insert a USB detector into the USB1 interface to check if the voltage polarity is correct. Finally, press the “Igniter” button to check if the igniter is heating up.
Debugging is completed, the back cover is installed, and the work meets the design requirements and can be used.
5、Innovation points and application display
The multifunctional emergency power supply has a simple and reasonable structure, is convenient to use, and has a variety of functions. It can achieve functions such as emergency charging, emergency lighting, radio reception, and manual power generation. Moreover, the power supply is equipped with an ignition device, which can meet the user’s outdoor fire needs.
The functional demonstration is as follows:
