An emergency radio is a small radio that can be used in emergency situations like in a disaster or other such events. The radio may be serving the same purpose of listening to the local stations. An emergency however has a basic difference with standard radios as well. An emergency radio may or may not use battery power as a primary source of power for operation. These radios may take their power from the human (known as a dynamo radio) or from other sources like the sun (known as solar powered radios).
The advantage these radios can have over standard battery powered radio is that they can work on the power sources which may be readily available. A human hand and sun can be found almost anywhere whether in the forest or in a place that has been struck by a disaster. If the sun is not available like in the night, the radio can be powered by the hand. The point being that it may not be disabled for the reason that no battery power is available. And radio can sometimes help in listening to important news and updates which can also have some important instructions for the people of a specific area.
A hand powered radio can also be called a dynamo radio which has a small crank which is rotated to charge an internal built in battery used to power the radio. The operation time of the radio can vary because it may consume more battery when the volume level is high. The radio can be charged again so by rotating the crank so that it’s normal operation may continue.
A solar powered radio may have a small photovoltaic cell which can convert the sun’s rays into electrical energy. A solar powered radio may have a built in battery which is charges through the solar cells in order to run the radio. The size of the cell can mostly be enough to run the radio at normal volume level for the time when the sun is shining bright. If not used at that time, the radio’s rechargeable batteries can be charges by keeping it in the sunlight for later use maybe in the night.
Some of such radios may also have a small charging port for cell phones so that they may be charged from the solar energy or dynamo power in case a standard powered supply is not available.