The equipment which can be controlled The equipment which works by the resistance. Such as the the tungsten-filament lamp, the soldering iron and so on. The equipment which is using the AC series motor(with the brush). Such as the drill, the electric fan, the cleaner and so on. The equipment which can not do the control The fluorescence light. The synchronous motor(using the capacitor) As for the synchronous motor, the number of rotations is decided by the frequency of the alternating current. So, basically, it isn't possible to control with the circuit this time. However, the torque(power to turn) of the motor declines when the electric current which flows through the synchronous motor decreases. With it, the revolution can be slowed down. In this case, with the load which is applied to the axis of the motor, the number of rotations isn't constant. The electric power which can be controlled is decided by the permission value of the electric current which can pour into the TRIAC. I used the TRIAC which can apply the 12-A electric current to the circuit this time. In the calculation, in case of AC 100V, a maximum of 1200 W can be controlled but in the actual use, about 700 W or 800 W are safe.