Solar Lights: How They Work Part II
As discussed in Part 1, solar lights generate and store their own power during the day, then release it at night to light your outdoors. An outdoor solar light is made up of six components, including the casing.
Solar Light Casing: The casing of the solar lights can be manufactured in many different materials; brass, bronze, copper, stainless steel, durable plastic, etc. Even the durable plastic is strong enough to last absolutely years. Any casing should be wiped down with a damp cloth periodically to remove layers of dirt.
Solar Panel: also called solar cells, or photovoltaic (PV) modular cells, which is a group of cells electronically connected and packaged in one frame. Solar cells are created with silicon which has impurities added to it, to allow electrical current to pass to the diode, also known as doping. Silicon crystals are expensive to make and the major expense of the solar light. The solar panel converts sunlight directly into electricity, charging the NiCd or NiMH rechargeable battery, then transferred to the LED diode. Solar cells are wired directly to the battery through the diode, which prevents the battery’s current from flowing back through the solar cell at night.
NiCd or NiMH Rechargeable Battery: Nickel-Cadium (NiCd) or Nickel-Metal Hydride (NiMH) batteries are designed to operate from fully charged to fully discharged. An AA size NiCd battery produces about 1.2 volts, and can store a maximum of approximately 700 milliamp-hours. NiMH batteris are a type of secondary electrochemical cell similar to an NiCd. NiMH uses a hydrogen absorbing alloy for the negative electrode instead of cadmium. As in NiCd cells, the positive is nickel oxide hydroxide (NiOOH). A NiMH charging voltage is 1.4-1.6 volts per cell, and can have 2-3 times the capacity of an equivalent size NiCd. A good quality NiMH will generally last up to 1,000 nights.
Photoresistor Cell: Located on the exterior of the casing, sends input to the controller board that darkness is occurring.
Controller Board: Accepts power from the solar cell and battery. When the photoresistor indicates darkness to the controller board, the controller board activated the battery. The three-transistor circuit turns on the LED light.
Light Emitting Diode (LED): A diode is the simplest possible semi-conductor device, and allows current to flow in one direction, but not the other. Basically, a diode is a one-way turnstile for electrons. One LED emits roughly the same brightness as a 2 watt incandescent bulb. The tiny LED bulb fits into an electrical circuit and illuminates solely by movement of electrons in a semi-conductor material, and lasts as long as a standard transistor. There is no filament to burn out, which is why LED lights have a lifespan of 100,000 hours, which is over 25 years.
That is how solar lights work, very simple, very few components, and the energy to have light outdoors at night is supplied completely free of charge, by the sun.
Check out all of our Solar Lights products at www.NaturesSolarLights.com. Go Green!
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