Fig. 1
The instant this is done the current causes the iron cores to become magnets, they attract A, which then breaks contact at S. The spring mounting of A causes it to jump back to its first position, S then touches the platinum disc again, the current flows as before, and the armature is again attracted only to break contact with S and fly back.
This continual making and breaking of the circuit keeps up as long as the push is pressed, a ball mounted on A by means of a rod strikes against the gong G causing a continuous ringing of the bell. The wires leading between the bell, battery cell and push must all be insulated, that is, covered with cotton, rubber, etc., which prevents the leakage of current should two wires cross each other. Copper wire is mostly used for circuits indoors, the details of the kind and size of wire will be given later on.
The main parts of an electric bell circuit are then—the battery to supply the electric current; the circuit, or wires, to carry this current; a push, or circuit breaker, to control the current flow; and a bell to utilize the current.
CHAPTER I
The Battery
The Battery Cell.
The battery cell most used in electric bell work is the Leclanche, or some modification of it.
