Secondary Coil (Nodeshell rescue)
The primary coil is a transformer's input and the secondary coil can be considered as its output. Mutual induction causes voltage to be induced in the secondary coil.
By altering the number of coil turnings, one can change the voltage output. The input and output voltages are directly proportional to the number of turnings used. A transformer which generates a higher voltage output than input is called a step-up transformer, whereas one which lowers the voltage is called a step-down transformer. | 
