4. Alternating current generators can be used at any speed without the use of governors.
43-a. The Esselbé Rotary Aero Motor. Four Pistons are Contained in the Ring Shaped Cylinder at the Left Which are so Connected with Cranks and Gears in the Gear Box that the Pistons and the Cylinder Rotate in Opposite Directions. As the Pistons Rotate they also Oscillate Back and Forth in Regard to One Another, so that the Working and Compression Strokes are Performed. From Aero London.
When installing an ignition system give due consideration to the reliability of the source of current. The gas engine is no more reliable than its source of current. Failure of the current means the failure of the engine.
(80) Primary Batteries.
Current is produced in a primary battery by the chemical action of a fluid known as an ELECTROLYTE upon two dissimilar metals or solids known as the electrodes. One of the electrodes, the negative, is usually made of zinc which is more readily attacked by the electrolyte than the positive electrode. As the metal of the negative electrode is dissolved and passes into the solution during the process of current generation, the electrolyte is also exhausted. The production of current is accompanied by the liberation of hydrogen gas from the electrolyte from which it is displaced by the zinc taken into solution.
When the electrodes are immersed in the electrolyte, and the outer ends of the electrodes are connected with a wire, a current will flow from the positive electrode to the negative through the wire, and from the negative to the positive electrode through the fluid. It will be seen that to complete the circuit between the electrodes it is necessary that the current flows through the electrolyte.
Electrical energy is actually generated in the primary battery by the chemical combustion of the negative electrode in the same way that heat energy is developed by the burning of a fuel.
By connecting the binding posts of the electrodes to the two wires of the external circuit, a current will flow through the circuit as long as the electrodes remain undissolved, or until the positive electrode is covered with hydrogen gas bubbles.
The bubbles of gas tend to insulate the positive electrode from the electrolyte or fluid, thus breaking the circuit through the fluid, and stopping the flow of current. This action is known as polarization.