Compressor unit and control device used thereby

A compressor unit containing a compressor element (1) driven by a motor (3) which is provided with an outlet pipe (15) and an inlet pipe (7), and a compressed air receiver (14) onto which the outlet pipe (15) is connected, whereby a pneumatically controlled throttle valve (9) is provided in the inlet pipe (7), whereas the motor (3) has a pneumatically controlled speed regulator (6), and whereby the speed regulator (6) and the throttle valve (9) are connected to the compressed air receiver (14) via a compressed air pipe (26), said compressed air pipe having a control device (18) with a control valve therein characterized in that the control valve is an electropneumatic valve (19) which is coupled to an electronic control (20), and wherein a first pressure sensor (21) is connected to the compressed air receiver (14) which transforms a measured compressed air receiver pressure in the compressed air receiver (14) to an electric signal;

• a second pressure sensor (22) is installed in the compressed air pipe (26) between the electropneumatic valve (19) and the speed regulator (6) and the throttle valve (9) in order to measure an actual regulating pressure exerted on said speed regulator (6) and the throttle valve (9) and to transform the measured regulating pressure to an electric signal, and
• whereby the electronic control (20) is electrically connected to said first and second pressure sensors (21 and 22) and to a means for adjusting nominal pressure (25a) which adjusts a nominal pressure, said electronic control (20) having means for controlling the electropneumatic valve (19) according to the signals received from said first and second pressure sensors (21 and 22) and according to a signal received from said means for adjusting nominal pressure (25).