Previous publication of the introduction of solar panels and related small production, led to many including this writer, the reader's interest. Nothing else, whim, decided to use two on hand a miniature solar panel DIY solar power system, simulation of modern solar power, but can also use it to power small devices play.
Solar power is the basic principle: usually the collected light energy into electrical energy stored in the open load up the release of stored energy. A typical example is the solar power solar street light: there is sunlight in the daytime when they are battery charging, the battery to the bulb through the night on the (now mostly low-power bright LED) power for lighting. Many cities have begun to use this main road street lights solar power. A practical solar power is more complex, but no matter how complex, is the original aim of the principle. Of course, we make a mini solar power is not necessary to do less complex.
The principle of solar panels and design
In understanding the actual solar power, the author began to design solar panels, my whole idea is: by solar panels to charge 1.2V rechargeable battery energy storage, then use the boost circuit to boost the 1.2V above 3V for the load. Some people may say: Why not a few rechargeable batteries in series to energy storage and output it, this is not the boost circuit can be omitted? Why turn such a bend to the middle of it? Because we use solar panels to recharge the battery, after all, solar panels have few opportunities to generate higher voltage, the battery voltage is too high will cause its own can not be charged. I do this for a solar panel, good lighting in the room by the window where the output voltage can be above 1.2 volts (connected in the circuit, the non-load state), so start to the rated voltage of 1.2 V of the battery charge, but if you want to make it more than the output voltage of 3V to afraid to go to get the sun. Using a battery energy storage has the advantage that light intensity can greatly reduce the charge request to extend the battery charging time.
Solar-powered circuit board shown in Figure 1. By the D1, BT constitute the system of solar charging circuit. Usually, if a certain light intensity, solar panels will charge through diode D1 to charge the battery BT, until saturation. In addition to solar charging, I also designed a spare external DC power charging port to avoid contingencies. External charging circuit consists of R1, DS1, D2, BT form, R1 1W power resistor selection, when R1 is 10 ohms when the best external charging voltage of 3-4 V, DS1 external charging indicator light, it is the use of voltage drop on the resistor R1 to lit. Step behind the use of blocking oscillator circuit is the fast turn-off (as) the characteristics of the realization of step-up. S1 for the power switch S1 is closed when the boost circuit to work, solar panels that can drive the load, J1 for the output interface, DS2 is the output indicator.
Component selection
Commercially available solar panels prices are generally higher, but we do not need to buy a lot of solar panels, can be moderate. After measurement, used in the production of solar panels in a single open circuit voltage can reach 4.2V, short-circuit current up to 38mA. The whole system is used in million circuit boards (commonly known as "hole plate") on the structures, so the need to prepare for a million with the circuit board. Figure 2 is ready for solar panels and two hole plate. Use a battery rated at 1.2V common 5 NiMH rechargeable battery. Boost circuit can be used inside a single cell highlighted LED flashlight ready boost circuit boards. The author is the demolition of an abandoned single-cell LED flashlight which highlighted the boost circuit boards. For myself, the inductor T1 F8mm with F0.4mm enameled wire in a small ring around the 15 laps, respectively, and 9 ring, small ring can be removed from the waste out of energy-saving lamps, diode IN5819 IN4148 if no alternative is available, C1 100uF tantalum capacitors used, if not also be used instead of electrolytic capacitor equivalent, but slightly lower efficiency.
Production process
First, a short cut welded wire solar panels in the two electrodes as a pin (Figure 3) in order to facilitate connections and fixed on the circuit board. Two solar panels is positive on the positive and negative on the negative (labeled above) use them in parallel, which can effectively enhance the solar panels to provide current capacity. After installing the solar panels shown in Figure 4.
Install energy storage, rechargeable batteries are shown in Figure 3 can also be a way to take the battery positive and negative terminal connected to the circuit board, which is welded on the pin at the battery terminals fixed to the circuit board, for stability, with a pointed metal Tools and then on the circuit board drilling reinforced with nylon straps (Figure 5).
Next to the bright LED flashlight used in the single cell removed a small piece of circuit board attached to step-up circuit board. Remove the circuit board to boost the two lines connecting the battery positive connection of a point in Figure 1, the negative pole b points; connected LED lamps positive connection c point of two lines, d point to the negative pole. I produced, the step-up circuit board by DuPont with the following pin connected to the main circuit plate board (Figure 6), this way you can take your own, as long as easy to produce on the line. If you do step-up their own circuit board traces directly to the tunnel, component selection has been detailed above, will not repeat them. Circuit is not complicated, you can play in the hole board free.
Figure 7 is made of solar panels after, made after the power supply can give a few small things, such as flashlights, radios and the like. Then highlight a few white LED, to become a solar LED flashlight, solar power panels in Figure 8 bright LED lights up the scene.
Due to the production volume of the issue without taking into account the lack of experience in this regard, the circuit board did not choose to do a little big shell, which was very easy to carry, so I hope to play lovers in the production of the imagination, the shape designed to be compact, so that While the appearance of more portable, increasing usability.
