Hydro Power

The dynamo is a mechanical engine, like the steam engine, the water turbine or the gas engine; and it converts the mechanical motion of the driven wheel into electrical motion,with the aid of a magnet.

The reaction turbine is best adapted to low heads, with a large supply of water. It is not advisable, under ordinary circumstances, to use it under heads exceeding 100 feet, as its speed is then excessive. It may be used under falls as low as two feet. Five thousand cubic feet of water a minute would give approximately 14 actual horsepower under such a head.

The principal items of cost in installing an impulse wheel are in connection with the pipe line, and the governor. In small heads, that is, under 100 feet, the expense of pipe line is low. Frequently, however, the governor will cost more than the water motor itself, although cheaper, yet efficient, makes are now being put on the market to meet this objection.

In general, there are two types of water wheels, the impulse wheel and the reaction wheel. Both are called turbines, although the name belongs, more properly, to the reaction wheel alone.

A weir is, in effect, merely a temporary dam set across the stream in such a manner as to form a small pond; and to enable one to
measure the water escaping from this pond. It may be likened to the overflow pipe of a horse trough which is being fed from a spring.