A very easy automatic solar light system ca be developed making use of some LEDs, a rechargeable battery and a small solar panel. The system instantly switches ON the lamps at dusk and switches them OFF at dawn.
The circuit design is very simple and might be known with the following factors:
As can be viewed in the presented circuit diagram, the design essentially includes a solar panel, a PNP transistor, few LEDs, a battery and a few resistors.
The transistor is the only active component which can be placed as a switch for stopping the battery voltage from achieving the linked LEDs throughout day time.
Throughout broad day light, the solar panel generates the essential amount of voltage which happens to be used across the rechargeable battery via the 1N4007 diode and the resistor R*. This voltage charges the battery gradually from dawn to dusk.
The resistor R* value ought to be modified according to the specifications of the battery for decreasing too much current to it.
The resistor also may serve as the current reducing resistor for the associated LEDs when the transistor is turned on.
Here it is often determined as 10 Ohms.
Provided that the solar panel yields the optimum amount of power, the positive potential at the base of the transistor keeps it turned OFF.
In spite of this when dusk sets in the solar voltage starts to decrease, just in case it falls below the zener diode rating, the transistor gradually begins carrying out, lighting the LEds slowly.
With total lack of sun light or when its totally dark, the transistor performs completely with the aid of the 1K resistor, and generates full brightness over the LEDs.
The next morning, the cycle repeats once again.
The circuit could be altered in lots of various ways.
The above diagram can also be integrated the following manner. It seems a lot more sensible now as the resistor is taken off the emitter for aiding economical initiating of the transistor.
The diagram demonstrates a defective transistor number (8050), make use of 8550 rather.
Suggested Solar Panel Specifications
6 to 8V/2 watt
Voltage - 6V
Current - 330 mA