Nowadays, the energy issue is closely watched by our human beings. The development of various new energy sources has already been put on the agenda. As a new energy source, solar energy is very widely used in civilian applications. At present, the application of non-main road solar street lights, solar garden lights and solar lawn lights, solar decorative lights, etc. has gradually formed scale. In the design of solar lamp, there are many factors involved in the control of the light source, the solar cell system, and the battery charge and discharge. Any problem in any one of the links will cause product defects.
In this paper, the external characteristics of solar cells, battery charge and discharge control, solar lighting fixtures often compare led and three-color high-efficiency energy-saving lamps, analyze their advantages and disadvantages and use occasions. At the same time, an improved method is proposed for the problems existing in the design of solar lamp circuits on the market. Due to its unique advantages, solar lamps have developed rapidly in recent years.
The lawn lamp has low power, mainly for decoration purposes, and has high requirements for mobility. In addition, the circuit is difficult to lay and the waterproof requirement is high. The above requirements make the lawn lamp powered by the solar battery show many unprecedented advantages. Especially in foreign markets, the demand for solar lawn lamps is very large compared to other products.
In 2002, only the solar cells consumed by Guangdong and Shenzhen for the production of solar lawn lamps reached 2MW, equivalent to one-third of the domestic solar battery production that year, and this year still maintained a strong development momentum, which was unexpected. Solar garden lights are widely used in parks, living quarters and non-main roads.
At the same time, due to the rapid development, some products are not mature enough in technology, there are many defects in the choice of light source and circuit design, which reduces the economy and reliability of the product and wastes a lot of resources. In view of the above problems, this paper puts forward its own views for the reference of factories producing solar lamps.
1) The characteristics of led are close to the stable diode, the working voltage changes by 0.1V, and the operating current may vary by about 20mA. For safety, the series current limiting resistor is used under normal conditions, and the great energy loss is obviously not suitable for the solar lawn lamp, and the LED brightness varies with the operating voltage. It is a good idea to use the booster circuit. You can also use a simple constant current circuit. In short, you must automatically limit the current, otherwise the LED will be damaged.
2) The peak current of general led is 50~100mA, and the reverse voltage is about 6V. Be careful not to exceed this limit, especially when the solar cell is reversed or the battery is unloaded. When the peak voltage of the booster circuit is too high, it is likely to exceed this limit. led.
3) The temperature characteristic of led is not good, the temperature rises by 5 °C, the luminous flux decreases by 3%, and it should be noted in summer.
4) The working voltage is discrete, the same model, the same batch of led working voltage has a certain difference, it should not be used in parallel. Must be used in parallel, and should consider current sharing.
5) Super bright white light led color temperature is 6400k~30000k. At present, the ultra-bright white light LED with low color temperature has not yet entered the market. Therefore, the solar lawn light produced by the ultra-bright white light LED has relatively poor penetrating ability, so it is necessary to pay attention to the optical design.
6) Static electricity has a great influence on super bright white LED. Anti-static facilities should be installed during installation. Workers should wear anti-static wrists. Super bright white light led by static electricity may not be visible by the eyes, but the service life will be shorter.