5-step controller with main protection and operation indicator lights for transformational speed of voltage controlled motors/fans. Five different speeds can be set on a connected motor/fan using the built-in device step switch. The switching circuit 1 is the lowest and the switching circuit 5 is the highest speed. The control circuit of the controller is protected by a 2 A fuse. The controllers are also available with connection for a flow monitor and a gas solenoid valve. The flow monitor must be installed in the air stream of the fan. If a sufficient amount of air is fed through the fan, the gas solenoid valve is activated via the flow monitor. The application range of these devices is favoured in the kitchen exhaust when gas appliances are installed.