What is working principle of electric circuit for solar lawn light ?

Solar lawn light is the most utilized for projects among solar pv industry in China, it is the unique solar application product which is controlled by adopting special IC (integrated circuit) in the world, its electric power is completely provided by semiconductor material, moreover, its lighting source is also semiconductor, it is semiconductor lighting product. With the global economic recovery in future, the total demand would increase in international market, at the same time, China’s market demand would gradually increase as well, It could have large potential requirement for villa, garden and Golf Course, etc.

With the rapid development of solar pv industry, companies which manufacture solar lawn light is gradually increasing and their scale is enlarger in China. Presently, China’s yield has been above 90% of the world, Over 0.3 billion sets would be sold out each year, the consumption of solar cells is 50~60MW. According to statistical data, the increasing speed of China’s average yield for solar lawn light has been exceeded 20% in recent years.

Working Principle for Solar Lawn Light
1. The Circuit Structure
Take a light-sensitive device with light-sensitive cell material as example, please check below circuit diagram. What we said light-sensitive cell serving as light-sensitive device is to exploit the light sensitive characteristic of solar cell, namely the output voltage of lighting solar cell, the output terminal would present high level; the output terminal of solar cell would have no voltage output when having no sunlight, then output terminal would appear low level.

This electric circuit is made up of battery charging circuit, power on/off circuit and drive circuit. Charging circuit consists of solar panel V1, diode D1 and battery V2. Power circuit is made up of audion Q1 and resistance R2. Drive circuit is made up of audion Q2.

2. Working Principle of Electric Circuit
According to above electric diagram, when having solar radiation, being equal to closing S1, connecting point 6. At the moment, the base electrode of audion Q1 appears high potential, Q1 is conduction ( collector and emitting electrode are conduction ), Q1 is under saturation situation, all of the current which gets through R2 would get through the collector of Q1 toward emitting electrode for ground connection, while there is nearly no any collector current to get through Q2, so Q2 is cut-off, namely, the collector and emitting electrode of Q2 have no current, the load LED1 has no current, stop to work.

At the same time, the electric power from solar cells gets through D1 to charge battery V2, another part gets through R2, collector and emitting electrode of Q1 to connect ground. As the internal resistance of battery is far less than R2, all of electric power from solar cells nearly transmits to battery V2.

When having no solar radiation, being equal to cutting off S1. At the moment, the base electrode of Q1 appears low potential, Q1 is cut-off (collector and emitting electrode are cut-off), Q1 is under cut-off situation, all of the current which gets through R2 would get through base electrode of Q2 towards emitting electrode to connect ground, so, Q1 is under expanding situation, namely, the base current and collector current of Q1 become β times coefficient, then the load LED1 normally work.

The advantage of Solar Lawn Light
Solar Lawn light is to exploit LED as lighting source, its lifespan is long with above 50000 hours, low working voltage, LED is very suitable for solar lawn light, especially the LED technology has got a great achievement and its property has a large improvement in past 5 years, its cost performance has got a large improvement as well. In addition, LED is powered by low current, the cost of lighting control is low, it can adjust strong or weak brightness and switch on or off, which can’t have any bad effect to LED. It is also convenient to control lighting color, to change lighting classifies, to produce dynamic effectiveness.
The power of solar lawn light is small, main purpose is for decoration, it is very easy to move, no need pave any cable, waterproof IP65, therefore, it has got a great development in market.

The developing tendency of solar lawn light
Solar power is treated as the burgeoning energy, it is being rapid developing because of its irreplaceable advantages. As the fourth generation new lighting source, solar lawn light has got an effective utilization for cities decoration, roadway illumination, courtyard brightness, indoor illumination and other illumination areas. Especially in remote area with lacking of electric power, solar lighting has more widely application prospect. In the past, most of people thought energy-saving lamp is a technology breakthrough because it can save four-fifths power, but LED can save a quarter of energy-saving lamp, which is a great innovation in solid light source. Moreover, LED has a superior lighting quality, no radiation, it is durable and reliable and low maintenance cost, which is typical green lighting source. The successful research of super brightness LED has greatly decreased the usage cost of solar lighting, and it is environmental friendly, easy to install, safe operation, economy and energy-saving. As LED has this advantages which is high lighting effectiveness and low heat, it has increasingly been applied for more and more illumination fields, and present the tendency to replace traditional lighting.

In the West of China, non-main road solar street light and solar courtyard light have gradually been large-scale. With the huge development of solar lighting, “Green Illumination” will be a kind of tendency.

Bingsolar Power, 24th, March, 2018