So far the motor starts when you press and stops when you press. In industry most circuits need time: the second motor starts five seconds after the first, the fan keeps running for a minute after the machine stops, the pump fills for 3 seconds and stops. That's the job of the timer. You'll learn the on-delay, the off-delay and the cyclic timer, and wire by hand all the trainer's timer exercises (practicals 14 to 24) on the board, with real time and a counter running on the timer.